Evaluation of the effects of feeding dried algae containing beta-1,3-glucan on broilers challenged with Eimeria.
Levine R,Horst G,Tonda R,Lumpkins B,Mathis G
This study determined the effect of a dried algae product containing beta-1,3-glucan on broiler performance and immunity during an Eimeria challenge. Heterotrophically grown Euglena gracilis, which contained ∼55% beta-1,3-glucan, was dried and milled for inclusion into a non-medicated starter diet. Two experiments were conducted to evaluate dietary treatments containing 0, 50, 100, 150, and 200 g/ton dried algae. In both experiments, male broilers were orally challenged on day 14 with a coccidial inoculum consisting of E. acervulina, E. maxima, and E. tenella. Fecal matter was collected 120-144 hours post-exposure to determine relative amounts of oocyte shedding and birds were sacrificed on day 20 for lesion scoring. Broiler performance was assessed on a weekly basis. In the first experiment, birds receiving dried algae at 50 and 200 g/ton showed a significant improvement in FCR compared to the infected control during the challenge period (days 14-20). In the second experiment, the dried algae treatment had no significant effect on FCR, but lesion scores were significantly reduced in the groups receiving 50, 150, and 200 g/ton dried algae relative to the infected control. In both experiments, the dried algae treatment did not significantly impact mortality or oocyte shedding. In the second experiment, staining of intestinal samples with fluorescently tagged antibodies demonstrated that dried algae at 100 g/ton increased the number of intestinal macrophages compared to the infected control. A significant and dose-dependent increase in intestinal MHC-II+ expression was also observed for birds fed dried algae, with an 8-fold increase observed in the 200 g/ton group relative to the infected control. Similarly, increased total immune cell density (measured by the mean fluorescence intensity of CD45+ cells) was also observed at 150 and 200 g/ton. Overall, these data suggest that dried algae rich in beta-1,3-glucan can help improve gut immunity and host protection, thereby reducing morbidity associated with coccidiosis.
Parasite-specific proliferative responses of chicken spleen cells upon in vitro stimulation with Eimeria tenella antigen.
Wattrang Eva,Thebo Per,Ibrahim Osama,Dalgaard Tina Sørensen,Lundén Anna
This study aimed to set up methodology to monitor parasite-specific T-cell activation in vitro using Eimeria tenella-infected chickens. A sonicated E. tenella sporozoite protein preparation was used for the activation of chicken spleen cell cultures. Proliferation assessed by 3H-thymidin incorporation or blast transformation of T-cells assessed by immunofluorescence labelling and flow cytometry were used as read-outs for activation. Results showed that E. tenella-specific proliferation was detected in cultures of spleen cells collected in a 'window' between 8 and 14 days after primary infection. However, due to high variation in proliferative responses between individuals and to high background proliferation, large numbers of observations were needed to obtain significant results. Moreover, the outcome was not improved by increasing the infection dose to chickens or by depletion of T-cell receptor (TCR) γ/δ expressing cells from cultures. An E. tenella-specific blast transformation response was observed for TCRα/β expressing cells within the same 'window', confirming the identity of the responding cells as classic T-cells. Thus, it is possible to study the kinetics of E. tenella-specific T-cell responses in vitro. However, more in-depth phenotypic identification of the responding T-cells could improve the methodology.
Effects of the PI3K/Akt signaling pathway on the apoptosis of early host cells infected with Eimeria tenella.
Zhang Xuesong,Li Shan,Zheng Mingxue,Zhang Li,Bai Rui,Li Ruiqi,Hao Siyuan,Bai Bing,Kang Huixin
This study investigated the role of PI3K/Akt signaling pathway on host cell apoptosis in the early infection of Eimeria tenella. Chicken cecal epithelial cells were treated with apoptosis-inducer Actinomycin D (Act D) or PI3K/Akt signaling pathway inhibitor LY294002 and then infected with E. tenella. Results demonstrated that the E. tenella-infected group had less apoptosis 4-8 h after the infection and more apoptosis 12-20 h after the infection than the control group. At 4-20 h after the infection, the apoptotic/necrotic rate and the Caspase-3 activity in the Act D + E. tenella group were lower (P < 0.01) than those in the Act D-treated group. The p-Akt and NF-κB contents in the E. tenella-infected group were higher (P < 0.01) than those in the control group 4-12 h after the infection. However, the bad content and the Caspase-9/3 activity were lower (P < 0.05) in the E. tenella-infected group than in the control group. Compared with the E. tenella-infected group, the LY294002 + E. tenella group showed decreased p-Akt content and increased apoptotic/necrotic rate, bad content, NF-κB expression, membrane permeability transition pore (MPTP) openness, and Caspase-9/3 activity. Thus, the early development of E. tenella could inhibit host cell apoptosis by downregulating the Caspase-3 activity. Upregulating this activity promoted apoptosis. In addition, activating the PI3K/Akt signaling pathway inhibited the apoptosis of E. tenella host cells in the early infection by reducing the expression of the bad content, limiting the MPTP opening, and decreasing the Caspase-9 and Caspase-3 activities.
Comparison of the host cells apoptosis induced by precocious strains and virulent strains of Eimeria tenella.
Zhang Li,Zheng Ming-Xue,Xi Rou,Xu Zhi-Yong,Zhang Xue-Song,Zheng Long-Long,Bai Rui,Mi Cheng-Long,Hao Fei-Fei,Feng Yu-Ping
The present study aims to investigate the similarities and differences between the host cells apoptosis induced by virulent line of Eimeria tenella (Tsx) and precocious line (PTsx), which can provide a theoretical basis for the study of drugs and vaccines against coccidiosis. HE staining, Hoechst 33342/AnnexinV-FITC/PI composite staining, and ELISA were used to detect the infection rate, apoptosis rate, and Caspase-3 enzyme activity of host cells infected by PTsx or Tsx, respectively. The apoptotic rates and Caspase-3 absorbance of the inoculation groups were lower (P < 0.05 or P < 0.01) than those of the control group at 4 h, whereas the apoptotic rates and Caspase-3 absorbance of the inoculation groups were higher (P < 0.05 or P < 0.01) than those of the control groups at 24 to 120 h. At the same inoculation dose, there was no significant difference in the infection rate, apoptosis rate or Caspase-3 absorbance between Tsx groups and PTsx groups after E. tenella inoculation for 4 to 72 h (P > 0.05). However, these indicators of PTsx groups were lower (P < 0.01) than those of the same dose inoculated Tsx groups at 120 h. The apoptosis rates of cecal and glandular epithelial cells in the inoculated groups were higher (P < 0.01) than those in the control group after inoculated E. tenella 5 D in vivo, and the apoptosis rates of cecal and glandular epithelial cells in PTsx group was lower (P < 0.01) than that in the same dose inoculated Tsx group. These observations indicate that both Tsx and PTsx inhibit host cell apoptosis in the early development of E. tenella, induce host cell apoptosis in the middle and late stages, and the apoptosis-inducing effect on host cells increases with increasing dose. However, when the same dose of oocysts was inoculated, the amount of apoptosis induced by PTsx in late development was less than Tsx.
Effects of Eimeria tenella infection on the barrier damage and microbiota diversity of chicken cecum.
Zhou Bian-Hua,Jia Liu-Shu,Wei Shan-Shan,Ding Hai-Yan,Yang Jing-Yun,Wang Hong-Wei
The symbiosis of host and intestinal microbiota constitutes a microecosystem and plays an important role in maintaining intestinal homeostasis and regulating the host's immune system. Eimeria tenella, an obligate intracellular apicomplexan parasite, can cause coccidiosis, a serious intestinal disease. In this study, the effects of E. tenella infection on development parameters (villus height, crypt depth, mucosa thickness, muscularis thickness, and serosa thickness) and microbiota in chicken cecum were investigated. Fourteen-day-old male Hy-Line Variety Brown layer chickens were inoculated with sporulated oocysts of E. tenella. Cecal tissues were collected 7 d after inoculation. Relative density of goblet cells and glycoproteins were determined by Alcian blue periodic acid-Schiff staining and periodic acid-Schiff staining, respectively. Intestinal development parameters were also evaluated. Cecal contents were extracted, and the composition of cecal microflora was examined by Illumine sequencing in the V3-V4 region of the 16S rRNA gene. Results indicated that E. tenella infection destroyed the structure of cecal tissue and reduced the relative density of goblet cells and glycoproteins. Sequencing analysis indicated that E. tenella infection altered the diversity and composition of cecal microbiota. The populations of Proteobacteria, Enterococcus, Incertae, and Escherichia-Shigella decreased, and those of Bacteroidales and Rikenella significantly increased in the infected group compared with those in the control group. Hence, the pathological damage caused by E. tenella infection is associated with cecal microbiota dysbiosis, and this finding may be used to develop an alternative measure for alleviating the effect of coccidiosis on the poultry industry.
Eukaryotic elongation factor 2 is involved in the anticoccidial action of diclazuril in the second-generation merozoites of Eimeria tenella.
Zhou Bian-Hua,Jia Liu-Shu,Guo Hong-Wei,Ding Hai-Yan,Yang Jing-Yun,Wang Hong-Wei
Eimeria tenella, an obligate intracellular parasite, can actively invade the cecal epithelial cells of chickens and cause severe enteric disease. Eukaryotic elongation factor 2 (eEF2) plays a major role in protein synthesis and cell survival. This study aims to explore the exact mechanisms underlying diclazuril inhibition in second-generation merozoites of E. tenella. The eEF2 cDNA of the second-generation merozoites of E. tenella (EtEF2) was cloned by reverse transcriptase polymerase chain reaction and rapid amplification of cDNA ends. Diclazuril-induced expression profiles of EtEF2 were also analyzed. The cloned full-length cDNA (2893 bp) of the EtEF2 nucleotide sequence encompassed a 2499 bp open reading frame (ORF) that encoded a polypeptide of 832 residues with an estimated molecular mass of 93.12 kDa and a theoretical isoelectric point of 5.99. The EtEF2 nucleotide sequence was submitted to the GenBank database with the accession number KF188423. The EtEF2 protein sequence shared 99 % homology with the eEF2 sequence of Toxoplasma gondii (GenBank XP_002367778.1). The GTPase activity domain and ADP-ribosylation domain were conserved signature sequences of the eEF2 gene family. The changes in the transcriptional and translational levels of EtEF2 were detected through quantitative real-time PCR and Western blot analyses. The mRNA expression level of EtEF2 was 2.706 fold increases and the protein level of EtEF2 was increased 67.31 % under diclazuril treatment. In addition, the localization of EtEF2 was investigated through immunofluorescence assay. Experimental results demonstrated that EtEF2 was distributed primarily in the cytoplasm of second-generation merozoites, and its fluorescence intensity was enhanced after diclazuril treatment. These findings indicated that EtEF2 may have an important role in understanding the signaling mechanism underlying the anticoccidial action of diclazuril and could be a promising target for novel drug exploration.
Laboratory Growth and Genetic Manipulation of Eimeria tenella.
Pastor-Fernández Iván,Pegg Elaine,Macdonald Sarah E,Tomley Fiona M,Blake Damer P,Marugán-Hernández Virginia
Current protocols in microbiology
Eimeria is a genus of apicomplexan parasites that contains a large number of species, most of which are absolutely host-specific. Seven species have been recognized to infect chickens. Infection of susceptible chickens results in an intestinal disease called coccidiosis, characterized by mucoid or hemorrhagic enteritis, which is associated with impaired feed conversion or mortality in severe cases. Intensive farming practices have increased the significance of coccidiosis since parasite transmission is favored by high-density housing of large numbers of susceptible chickens. Routine chemoprophylaxis and/or vaccination with live parasite vaccines provides effective control of Eimeria, although the emergence of drug resistance and the relative cost and production capacity of current vaccine lines can prove limiting. As pressure to reduce drug use in livestock production intensifies, novel vaccination strategies are needed. Development of effective protocols supporting genetic complementation of Eimeria species has until recently been hampered by their inability to replicate efficiently in vitro. Now, the availability of such protocols has raised the prospect of generating transgenic parasite lines that function as vaccine vectors to express and deliver heterologous antigens. For example, this technology has the potential to streamline the production of live anticoccidial vaccines through the generation of parasite lines that co-express immunoprotective antigens derived from multiple Eimeria species. In this paper we describe detailed protocols for genetic manipulation, laboratory growth, and in vivo propagation of Eimeria tenella parasites, which will encourage future work from other researchers to expand biological understanding of Eimeria through reverse genetics. © 2019 by John Wiley & Sons, Inc.
RNA Sequencing Analysis of Chicken Cecum Tissues Following Infection in Vivo.
Wang Xiaohui,Zou Wenbin,Yu Hailiang,Lin Yuxin,Dai Guojun,Zhang Tao,Zhang Genxi,Xie Kaizhou,Wang Jinyu,Shi Huiqiang
() is one of the most frequent and pathogenic species of protozoan parasites of the genus that exclusively occupies the cecum, exerting a high economic impact on the poultry industry. To investigate differentially expressed genes (DEGs) in the cecal tissue of Jinghai yellow chickens infected with , the molecular response process, and the immune response mechanism during coccidial infection, RNA-seq was used to analyze the cecal tissues of an infection group (JS) and an uninfected group (JC) on the seventh day post-infection. The DEGs were screened by functional and pathway enrichment analyses. The results indicated that there were 5477 DEGs (-value < 0.05) between the JS and the JC groups, of which 2942 were upregulated, and 2535 were downregulated. GO analysis indicated that the top 30 significantly enriched GO terms mainly involved signal transduction, angiogenesis, inflammatory response, and blood vessel development. KEGG analysis revealed that the top significantly enriched signaling pathways included focal adhesion, extracellular matrix-receptor interaction, and peroxisome proliferator-activated receptor. The key DEGs in these pathways included , and . These genes play an important role in the infection of . This study further enhances our understanding of the molecular mechanism of infection in chickens.
Molecular characterization and immune protection of an AN1-like zinc finger protein of Eimeria tenella.
Zhao Huanzhi,Zhao Qiping,Zhu Shunhai,Huang Bing,Lv Ling,Liu Guiling,Li Zhihang,Wang Lu,Dong Hui,Han Hongyu
Coccidiosis is caused by multiple species of the apicomplexan protozoa Eimeria. Among them, Eimeria tenella is frequently considered to be the most pathogenic. Zinc finger proteins (ZnFPs) are a type of protein containing zinc finger domains. In the present study, a putative Eimeria tenella AN1-like ZnFP (E. tenella AN1-like zinc finger domain-containing protein, putative partial mRNA, EtAN1-ZnFP) was cloned and characterized, and its immune protective effects were evaluated. The 798-bp ORF sequence of EtAN1-ZnFP that encoded a protein of approximately 27.0 kDa was obtained. The recombinant EtAN1-ZnFP protein (rEtAN1-ZnFP) was expressed in Escherichia coli. Western blot analysis showed that the recombinant protein was recognized by the anti-GST monoclonal antibody and anti-sporozoite protein rabbit serum. qPCR analysis revealed that EtAN1-ZnFP was highly expressed in unsporulated oocysts and sporozoites. Immunostaining with an anti-rEtAN1-ZnFP antibody indicated that EtAN1-ZnFP was uniformly distributed in the cytoplasm of sporozoites, except for the refractive body; furthermore, this protein was evenly distributed in the cytoplasm of immature schizonts but seldom distributed in mature schizonts. The results of the in vitro invasion inhibition assay indicated that the antibodies against rEtAN1-ZnFP efficiently reduced the ability of E. tenella sporozoites to invade host cells. Animal challenge experiments demonstrated that the chickens immunized with rEtAN1-ZnFP protein significantly decreased mean lesion scores and fecal oocyst output compared with challenged control group. The results suggest that EtAN1-ZnFP can induce partial immune protection against infection with E. tenella and could be an effective candidate for the development of new vaccines.
Molecular characterization of surface antigen 10 of Eimeria tenella.
Liu Guiling,Zhu Shunhai,Zhao Qiping,Dong Hui,Huang Bing,Zhao Huanzhi,Li Zhihang,Wang Lu,Han Hongyu
Chicken coccidiosis is caused by the apicomplexan parasite Eimeria spp. At present, drug resistance of Eimeria is common because of the indiscriminate use of anticoccidial drugs. The gene encoding surface antigen 10 of Eimeria tenella (EtSAG10) is differentially expressed between drug-resistant and drug-sensitive strains. RNA-seq analysis indicated that this gene was downregulated in strains resistant to maduramicin and diclazuril compared to susceptible strains. EtSAG10 DNA sequence alignment revealed that they contained one and ten mutations in MRR and DZR, compared with DS, respectively. A full-length EtSAG10 cDNA was successfully cloned and expressed, and the polyclonal antibody was prepared. The transcription and translation levels of EtSAG10 were analyzed by quantitative real-time PCR (qPCR) and Western blotting. The localization of EtSAG10 in Spz, Mrz, and parasites in the first asexual stage was determined by indirect immunofluorescence. The potential association of EtSAG10 with sporozoite invasion of host cells was assessed by invasion inhibition assays. The results showed that EtSAG10 had a predicted transmembrane domain at the C-terminal end and a predicted signal peptide at the N-terminal end. EtSAG10 was downregulated in drug-resistant strains, which is consistent with the RNA-seq results. The EtSAG10 protein was localized to the parasite surface and parasitophorous vacuole membrane. This protein was shown to play a role in the infection of chicken intestine by sporozoites.
Proteomic analysis of the second-generation merozoites of Eimeria tenella under nitromezuril and ethanamizuril stress.
Li Xue-Yan,Liu Li-Li,Zhang Min,Zhang Li-Fang,Wang Xiao-Yang,Wang Mi,Zhang Ke-Yu,Liu Ying-Chun,Wang Chun-Mei,Xue Fei-Qun,Fei Chen-Zhong
Parasites & vectors
BACKGROUND:Eimeria tenella is a highly pathogenic coccidian that causes avian coccidiosis. Both nitromezuril (NZL) and ethanamizuril (EZL) are novel triazine compounds with high anticoccidial activity, but the mechanisms of their action are still unclear. This study explored the response of E. tenella to NZL and EZL by the study of changes in protein composition of the second-generation merozoites. METHODS:Label-free quantification (LFQ) proteomics of the second-generation merozoites of E. tenella following NZL and EZL treatment were studied by LC-MS/MS to explore the mechanisms of action. The identified proteins were annotated and analyzed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and protein-protein interaction (PPI) networks analysis. RESULTS:A total of 1430 proteins were identified by LC-MS/MS, of which 375 were considered as differential proteins in response to drug treatment (DPs). There were 26 only found in the NZL treatment group (N-group), 63 exclusive to the EZL treatment group (E-group), and 80 proteins were present in both drug groups. In addition, among the DPs, the abundant proteins with significantly altered expression in response to drug treatment (SDPs) were found compared with the C-group, of which 49 were upregulated and 51 were downregulated in the N-group, and 66 upregulated and 79 downregulated in the E-group. Many upregulated proteins after drug treatment were involved in transcription and protein metabolism, and surface antigen proteins (SAGs) were among the largest proportion of the downregulated SDPs. Results showed the top two enriched GO terms and the top one enriched pathway treated with EZL and NZL were related, which indicated that these two compounds had similar modes of action. CONCLUSIONS:LFQ proteomic analysis is a feasible method for screening drug-related proteins. Drug treatment affected transcription and protein metabolism, and SAGs were also affected significantly. This study provided new insights into the effects of triazine anticoccidials against E. tenella.
Effect of vitamin A deficiency on host intestinal immune response to Eimeria acervulina in broiler chickens.
Dalloul R A,Lillehoj H S,Shellem T A,Doerr J A
The effects of vitamin A (VitA) deficiency on the host intestinal immune response and disease susceptibility to coccidiosis were investigated in broiler chickens following oral infection with Eimeria acervulina (EA). Day-old male broilers were fed milo-soybean meal diets either with 8,000 IU VitA/kg feed (CONT) or without added VitA (A-DEF). At 25 d, a group of randomly selected birds from each treatment was inoculated orally with EA-sporulated oocysts. Intestinal immune response was assessed by the changes in the duodenum intraepithelial lymphocyte (IEL) subpopulations using flow cytometry at 35 d in in fected and noninfected birds. Concanavalin A (ConA)-induced spleen lymphocyte proliferation was tested using dimethylthiazol diphenyltetrazolium bromide colorimetric assay. Whether challenged or not with EA, A-DEF birds had fewer IEL expressing the surface markers CD3, CD4, CD8, alphabetaTCR, and gammabetaTCR. Without EA challenge, A-DEF birds had more surface IgA-expressing cells than CONT birds. Upon challenge, A-DEF chickens showed lower CD4+ IEL than CONT chickens. Following EA infection, CD8+ IEL increased in the CONT group, whereas no change was found in CD8+ IEL of A-DEF birds. A higher number of EA oocysts was recovered from A-DEF birds than from CONT birds (9.2 x 10(8) vs 5.4 x 10(8), respectively; P < or = 0.05). Serum samples taken 10 d post challenge showed higher antibody level against a recombinant coccidial antigen in A-DEF birds than in CONT birds. The A-DEF birds showed depressed ConA-induced lymphoproliferation response and produced lower serum interferon-gamma than CONT birds. These data show that VitA deficiency compromised local immune defenses of challenged birds, as reflected in lymphocyte profiles, oocyst shedding, and interferon-gamma levels in A-DEF birds.
Effect of coccidial challenge and vaccination on the performance, veterinary postmortem scores, and blood biochemistry of broiler chickens.
Cowieson A J,Livingston M L,Nogal B,Hoang V,Wang Y-T,Crespo R,Livingston K A
A total of 960 male Cobb 500 broilers were used in a growth performance study to explore the effect of coccidial vaccination and/or coccidial challenge on blood biochemistry and veterinary postmortem metrics. Day-old chicks were randomly divided into one of the 4 experimental treatments. Treatments were arranged in a 2 × 2 factorial arrangement, with the factors being without or with vaccination (administered on day 1) or coccidial challenge (oral gavage on day 7). Growth performance was monitored on a weekly basis. Blood sample collection, as well as full veterinary necropsies, were carried out on days 6, 8, 13, 20, 27, and 34. Birds that did not receive the vaccination but were challenged with coccidiosis had higher feed conversion ratio, lower body weights, and higher mortality than the other experimental groups, and this effect was particularly evident from day 13 to day 20. Birds challenged with coccidiosis had lower plasma sodium and total carotenoid concentrations and higher potassium and globulin concentrations than nonchallenged birds. Significant interactions between age and experimental treatment for these blood parameters were observed, particularly on day 13. The necropsy results confirmed the effectiveness of the challenge and vaccination treatments, wherein birds that were challenged had higher coccidiosis scores on day 13 and day 27 than birds that were not challenged. These results demonstrate the potential for plasma sodium, potassium, total protein, total carbon dioxide, globulin, and carotenoid analysis for early diagnosis of coccidiosis in growing broiler chickens. Further work is necessary to establish whether the changes in blood biochemistry observed in the present study are transferable to alternative flocks of chicken and whether early diagnosis and intervention may mitigate performance losses associated with this disease.
The anticoccidial activity of the fluoroquinolone lomefloxacin against experimental Eimeria tenella infection in broiler chickens.
El-Shazly Kamal Ahmed,El-Latif Amera Abd,Abdo Walied,El-Morsey Ahmed,El-Aziz Magdy Ibrahim Abd,El-Mogazy Heba
Coccidiosis is a crucial parasitic disease of the poultry industry. As a result of the enormous global economic losses and the increased resistance to the conventional anticoccidial agents, there is a continuous need to find new anticoccidials. Here, the anticoccidial effect of the fluoroquinolone lomefloxacin versus diclazuril in experimentally infected broilers was tested for the treatment of Eimeria tenella infection. Ninety 14-day-old Cobb strain broiler chickens were allocated into five groups, each with 18 chicks. Group 1 (G1) was separated as an uninfected negative control and received no treatment; group 2 (G2), infected untreated (positive control); group 3 (G3), infected and treated with lomefloxacin at a dose rate of 100 ppm in drinking water; group 4 (G4), infected and treated with diclazuril at a dose rate of 2.5 ppm in drinking water; group 5 (G5), infected and treated with lomefloxacin at a dose rate of 100 ppm plus diclazuril at dose rate of 2.5 ppm in drinking water. Clinical signs, mortality rates, number of oocysts per gram of faeces (OPG), growth performance parameters (weight gain: WG and feed conversion ratio: FCR), lesion scoring, haematological and serum biochemical analyses, antioxidant biomarkers and histopathologic inspection of the caeca were used as evaluation criteria for the anticoccidial efficacy of both lomefloxacin and diclazuril. The findings herein showed that administration of lomefloxacin and/or diclazuril improved growth performance parameters (WG, FCR) and significantly (P ≤ 0.05) reduced OPG, and diminished the severity of bloody diarrhoea and mortalities. Additionally, haematological indices and serum biochemical parameters such as ALT, AST, ALP, creatinine, uric acid, total proteins, albumin and globulin were improved. Finally, a significant elevation in the levels of the antioxidant biomarkers was observed in the chicks of G3, G4 and G5 as compared with those of G2.
Differential expression of intestinal nutrient transporters and host defense peptides in Eimeria maxima-infected Fayoumi and Ross chickens.
Su S,Miska K B,Fetterer R H,Jenkins M C,Lamont S J,Wong E A
Fayoumi chickens are believed to be more disease resistant compared to commercial broiler chickens. The objective of this study was to compare mRNA expression of intestinal nutrient transporters, digestive enzymes, and host defense peptides (HDP) between Eimeria maxima-challenged Fayoumi and Ross broiler chickens. At 21 d of age, Ross broilers and Fayoumi lines M5.1 and M15.2 were challenged with 1,000 E. maxima oocysts. Control birds were not challenged. Duodenum, jejunum, and ileum were sampled (n = 6) at 7 d post challenge. Gene expression was analyzed using relative quantification PCR. Data were analyzed by ANOVA and significance level was set at P < 0.05. There was numerical, but not statistically significant, differential weight gain depression for Ross (15%) and Fayoumi lines M5.1 (21%) and M15.2 (22%) and significant line-specific changes in gene expression. For nutrient transporters, there was downregulation of mRNA for the brush border membrane, amino acid transporters b0,+AT/rBAT, BoAT, and EAAT3 in different segments of the small intestine of Ross and both lines of Fayoumi chickens, indicating that E. maxima challenge likely caused a decrease in nutrient uptake. For HDP, there was downregulation of avian beta defensin (AvBD) 1, 6, 10, 12, and 13 mRNA in the jejunum of the 2 Fayoumi lines, but no change in the Ross broilers. In the duodenum, there was upregulation of AvBD10 mRNA in the Ross and both Fayoumi lines and additionally upregulation of AvBD11, 12, and 13 mRNA in only Fayoumi line M15.2. Liver expressed antimicrobial peptide 2 (LEAP2) mRNA was downregulated in the duodenum and jejunum of Ross and Fayoumi line M5.1 but not in Fayoumi line M15.2. The homeostatic, non-challenged levels of AvBD mRNA were greater in Fayoumi line M15.2 than Ross and Fayoumi line M5.1 in the duodenum and ileum. This study demonstrates tissue- and genetic line-specific transcriptional responses to E. maxima, highlights novel potential candidate genes for response to coccidiosis, and confirms a role for several previously reported genes in response to coccidiosis.
The effects of dietary Bacillus subtilis supplementation, as an alternative to antibiotics, on growth performance, intestinal immunity, and epithelial barrier integrity in broiler chickens infected with Eimeria maxima.
Park Inkyung,Lee Youngsub,Goo Doyun,Zimmerman N P,Smith A H,Rehberger T,Lillehoj Hyun S
The objective of this study was to investigate the effects of dietary Bacillus subtilis supplementation on growth performance, jejunal lesion scores, oocyst shedding, and cytokine and tight junction protein expression in broiler chickens infected with Eimeria maxima. A total of 196 male day-old Ross 708 broilers were given a nonexperimental diet until 14 D of age. Then, all chickens were randomly assigned to one of seven dietary treatments: 2 basal diets (CON and NC); CON + virginiamycin (AB1); CON + bacitracin methylene disalicylate (BMD; AB2); CON + B. subtilis 1781 (PB1); CON + B. subtilis 747 (PB2); or CON + B. subtilis 1781 + 747 (PB3). At day 21, all chickens except those in the CON group were orally inoculated with E. maxima oocysts. At 7 D after E. maxima infection, the body weight gains of chickens fed PB2 and PB3 increased (P = 0.032) as much as those in chickens fed AB2. The body weight gain and feed efficiency of chickens fed PB2 were significantly increased (P < 0.001), and PB2 chickens showed (P = 0.005) the lowest lesion scores after E. maxima infection. Chickens fed PB2 showed (P < 0.05) lower mRNA expression of IL-1β in infected chicken groups. Chickens in the AB1, AB2, PB1, PB2, and PB3 groups showed (P < 0.05) greater mRNA expression of junctional adhesion molecule 2 in jejunal tissue, whereas occludin expression increased (P < 0.05) in the jejunal tissue of chickens fed AB2 or PB2. Dietary B. subtilis supplementation significantly improved the growth performance of young chickens to a level comparable with that induced by virginiamycin or BMD without E. maxima infection. After infection with E. maxima, dietary virginiamycin and BMD significantly enhanced the epithelial barrier integrity, and the dietary B. subtilis 747 showed significantly enhanced growth performance, intestinal immunity, and epithelial barrier integrity. Together our results indicated that certain strains of B. subtilis provide beneficial effects on the growth of young broiler chickens and have the potential to replace antibiotic growth promoters.
Dissection of the cecal microbial community in chickens after Eimeria tenella infection.
Chen Hong-Liang,Zhao Xin-Yu,Zhao Guang-Xun,Huang Hai-Bin,Li Hao-Rui,Shi Chun-Wei,Yang Wen-Tao,Jiang Yan-Long,Wang Jian-Zhong,Ye Li-Ping,Zhao Quan,Wang Chun-Feng,Yang Gui-Lian
Parasites & vectors
BACKGROUND:Eimeria spp. are responsible for chicken coccidiosis which is the most important enteric protozoan disease resulting in tremendous economic losses in the poultry industry. Understanding the interaction between the avian cecal microbiota and coccidia is of interest in the development of alternative treatments that do not rely on chemotherapeutics and do not lead to drug resistance. METHODS:We utilized 16S rRNA gene sequencing to detect the dynamics of the cecal microbial community in AA broilers challenged with Eimeria tenella. Histopathological analysis of the cecum was also conducted. RESULTS:We found that microbial shifts occur during the infection. Lactobacillus, Faecalibacterium, Ruminococcaceae UCG-013, Romboutsia and Shuttleworthia decreased in abundance. However, the opportunistic pathogens Enterococcus and Streptococcus increased in abundance over time in response to the infection. CONCLUSIONS:Eimeria tenella disrupts the integrity of the cecal microbiota and could promote the establishment and growth of potentially pathogenic bacteria. Defining bacterial populations affected by coccidial infection might help identify bacterial markers for intestinal disease as well as populations or species that could be beneficial in maintaining and restoring gut homeostasis during and after infection with E. tenella.
Effect of Cocciban herbal coccidiostats on hematobiochemical, fecal parameters and cecal histopathology of broiler chicken.
B Srinivasu,Preetam V Chinni,Srinivas Gurram,Rao D Srinivas
Tropical animal health and production
The objective of the present study was to investigate the comparative efficacy of recommended dose of selected anticoccidial drugs Salinomycin and Dinitolmide, while Cocciban at three dose levels on the hematobiochemical, fecal parameters and histopathology of broilers. For this purpose, 420-day-old commercial male broiler chicks were randomly divided into 7 treatment groups with 10 replications of 6 birds each and reared in battery brooders up to 42 days of age. Groups were designated as uninfected unmedicated (T), infected unmedicated (T), Cocciban 500 g/ton and infected (T), Cocciban 750 g/ton and infected (T), Cocciban 1000 g/ton and infected (T), Salinomycin 500 g/ton and infected (T), and Dinitolmide and infected (T). Groups T, T, T, T, T, and T were experimentally infected at 21-day-old by 50,000 oocysts of Eimeria species. The mean fecal, lesion scores and oocyst per gram of feces were significantly (p < 0.05) highest in infected unmedicated group, while lowest in the herbal Cocciban 1000 g/ton group than all other infected medicated groups. The hematological studies revealed a reduction in TEC, Hb, and PCV from 0 to 5th day of P.I. in all infected groups except healthy control group. The birds of all the infected groups improved in the values of TEC, Hb, PCV, blood glucose, and total serum protein on 7th day of P.I., but, the improvement was significantly (p < 0.05) better in herbal Cocciban 1000 g/ton treated birds than all other infected groups. Whereas, the TWBC counts were raised from 0 to 7th day of P.I. in all the infected groups compared to healthy control and no significant (p < 0.05) difference was observed in between the infected groups. The histopathological changes consisting of desquamation of epithelial cells, cellular infiltration, hemorrhages, edema, fibrous tissue proliferation, and developing stages of E. tenella at various depths of cecal wall were higher in all the infected groups when compared to Cocciban 1000 g/ton group.
Modulation of the intestinal microbiota of broilers supplemented with monensin or functional oils in response to challenge by Eimeria spp.
Vieira Alexandre Maciel,Soratto Tatiany Aparecida Teixeira,Cardinal Kátia Maria,Wagner Glauber,Hauptli Lucélia,Lima André Luis Ferreira,Dahlke Fabiano,Peres Netto Diego,Moraes Priscila de Oliveira,Ribeiro Andréa Machado Leal
The objective of this study was to evaluate the effect of supplementation with 100ppm sodium monensin or 0.15% of a blend of functional oils (cashew nut oil + castor oil) on the intestinal microbiota of broilers challenged with three different Eimeria spp. The challenge was accomplished by inoculating broiler chicks with sporulated oocysts of Eimeria tenella, Eimeria acervulina, and Eimeria maxima via oral gavage. A total of 864, day-old male broiler chicks (Cobb) were randomly assigned to six treatments (eight pens/treatment; 18 broilers/pen) in a 3 × 2 factorial arrangement, composed of three additives (control, monensin or blend), with or without Eimeria challenge. Intestinal contents was collected at 28 days of age for microbiota analysis by sequencing 16s rRNA in V3 and V4 regions using the Illumina MiSeq platform. Taxonomy was assigned through the SILVA database version 132, using the QIIME 2 software version 2019.1. No treatment effects (p > 0.05) were observed in the microbial richness at the family level estimated by Chao1 and the biodiversity assessed by Simpson's index, except for Shannon's index (p < 0.05). The intestinal microbiota was dominated by members of the order Clostridiales and Lactobacillales, followed by the families Ruminococcaceae, Bacteroidaceae, and Lactobacillaceae, regardless of treatment. When the controls were compared, in the challenged control group there was an increase in Erysipelotrichaceae, Lactobacillaceae, Bacteroidaceae, Streptococcaceae, and Peptostreptococcaceae, and a decrease in Ruminococcaceae. Similar results were found for a challenged group that received monensin, while the blend partially mitigated this variation. Therefore, the blend alleviated the impact of coccidiosis challenge on the microbiome of broilers compared to monensin.
The effect of sodium bisulfate and coccidiostat on intestinal lesions and growth performance of Eimeria spp.-challenged broilers.
Talghari Mariam,Behnamifar Alireza,Rahimi Shaban,Karimi Torshizi Mohammad Amir,Beckstead Robert,Grimes Jesse L
Coccidiosis is a high-prevalence disease that annually entails huge costs for the poultry industry. Control of coccidiosis in poultry production is based on the use of coccidiostats and vaccines. However, along with the problem of drug resistance, there is a concern about food safety and drug residues in poultry products. The objective of this study was to evaluate the effect of sodium bisulfate (SBS) in comparison with monensin (M) and their combination (SBSM) effects on controlling coccidiosis in broilers. In a randomized design, 300 chickens (Ross 308) were divided into 5 treatments and 4 replications (15 birds per replicate). All birds, except the negative control (NC), were orally inoculated with 4 Eimeria species on 14 D of age. Treatments included were as follows: NC, an unsupplemented basal diet, nonchallenged; positive control, a basal diet unsupplemented, challenged with Eimeria spp; a basal diet supplemented with 5 g/kg of SBS; a basal diet supplemented with 1 g/kg of M; and a basal diet supplemented with 5 g/kg SBS and 1 g/kg M (SBSM). Oocyst shedding per gram (OPG) of the faecal sample from each experimental unit was counted on 5 to 14 D after inoculation. Two chicks from each experimental unit were euthanized to investigate intestinal lesions on day 5 after inoculation. The NC birds showed the highest BW gain and the lowest feed conversion ratio. The birds in the SBSM group had improved feed consumption compared with the M group in the prechallenge period (P < 0.05). All supplemented treatments resulted in a significant decrease in OPG. The M and SBSM treatments showed more efficacy than the SBS group (P < 0.05) in reducing OPG. There was a significant reduction in cecal lesions owing to supplementation with SBS, but the effect of SBS in the upper part of the intestine was lower than the M and SBSM groups (P < 0.05). Based on the results of this study, SBS has protective effects against coccidiosis in ceca, and the combination of M and SBS (SBSM) did not show any further improvement effect compared with M alone on the control of coccidiosis.
Effects of dietary methionine plus cysteine levels on growth performance and intestinal antibody production in broilers during Eimeria challenge.
Ren Zhouzheng,Bütz Daniel E,Whelan Rose,Naranjo Victor,Arendt Maria K,Ramuta Mitchell D,Yang Xiaojun,Crenshaw Thomas D,Cook Mark E
Research has shown that methionine+ cysteine (M+C) requirements may be higher when chickens are infected with Eimeria app. In a 4 × 2 factorial design, broilers (11 to 21 D) were fed one of 4 corn-soybean meal-based diets containing either 0.6, 0.8, 0.9, or 1.0% standardized ileal digestible (SID) M+C; on day 14, broilers from each diet were gavaged with either phosphate-buffered saline (PBS) or a commercial coccidiosis vaccine (at 100 × vaccine dose) which provide a mixture of live Eimeria acervulina, Eimeria maxima, and Eimeria tenella oocysts. Growth performance was recorded from day 11 to 21. Plasma and intestinal luminal samples were collected on days 14 and 21. Intestine lesion scores and fecal oocyst counts were conducted on day 21. Regardless of dietary SID M+C levels, compared to PBS gavaged broilers, the Eimeria-challenged broilers had (1) decreased (P < 0.05) body weight gain (BWG), feed intake (FI), and gain-to-feed ratio (G:F); (2) increased (P < 0.05) intestinal lesion scores and fecal oocyst counts; (3) increased (P < 0.05) plasma anti-Eimeria IgG, and intestinal luminal total IgA and anti-Eimeria IgA concentrations; and (4) increased (P < 0.05) levels of duodenum luminal gamma interferon (IFN-γ) and interleukin-10 (IL-10), as well as jejunum and cecum luminal IFN-γ concentrations. Regardless of Eimeria challenge, when compared to 0.6% SID M+C, broilers fed ≥0.8% SID M+C had (1) increased (P < 0.05) BWG, FI, and G:F and (2) increased (P < 0.05) levels of jejunum luminal total IgA. After Eimeria challenge, broilers fed 0.8% SID M+C had increased (P < 0.05) levels of jejunum luminal anti-Eimeria IgA compared to broilers fed diets containing 0.6 and 1.0% SID M+C. Collectively, in 11- to 21-D broilers, the growth suppression caused by Eimeria infection could not be mitigated by further increasing dietary M+C alone ≥0.8%. Further research should investigate interactions between dietary M+C and other nutrients for support of immune function and growth in pathogen-challenged broilers.
Effects of dietary amino acid density and feed allocation during the starter period on 41 days of age growth performance and processing characteristics of broiler chickens given coccidiosis vaccination at hatch1.
Cloft S E,Rochell S J,Macklin K S,Dozier W A
A study was conducted to determine if increasing digestible (dig) amino acid (AA) density or feed allocation of starter diets fed to broilers receiving coccidiosis vaccination can ameliorate poor cumulative growth performance and reduce meat yield. A total of 1,600 Yield Plus Ross × Ross 708 male broilers were assigned to a 2 × 3 factorial arrangement of dig AA density [moderate (1.15% dig Lys) and high (1.25% dig Lys)] and feed allotment (0.45, 0.73, and 1.00 kg/bird) with 2 positive control treatments during the starter period. Diets were formulated to essential AA ratios relative to dig Lys. Vaccinated birds received a 1x dosage of Coccivac- B52 prior to placement, whereas non-vaccinated birds in the positive control groups were fed diets containing diclazuril. Following consumption of the starter diets, birds were provided common grower and finisher diets. Broilers fed the high AA density diet during the starter period had higher cumulative BW gain and lower cumulative feed conversion ratios (P < 0.05) than those fed the moderate AA density diet. Broilers fed the high AA density diet had heavier (P ≤ 0.005) carcass and total breast weights than birds fed the moderate AA density diet. Broilers fed a starter allotment of 1.00 kg/bird produced heavier carcass weights (P ≤ 0.006) than did birds provided lower allotments. Additionally, broilers fed the high AA density diet had a greater percentage of 0 scores (P = 0.005) for the upper intestinal region during scoring. Results from this study indicated that feeding the high AA density diet at higher feed allotments during the starter period resulted in increased AA intake, which supported the bird through the vaccine challenge and enhanced the cumulative growth and meat yield.
Effects of Yucca schidigera-derived saponin supplementation during a mixed Eimeria challenge in broilers.
Oelschlager M L,Rasheed M S A,Smith B N,Rincker M J,Dilger R N
An experiment was conducted to determine if dietary Yucca-derived saponin supplementation could ameliorate the immune and growth responses of broilers during a mixed coccidian challenge. A total of 576 two-day-old male Ross 308 broiler chicks were housed in galvanized starter batteries and randomly assigned to 1 of 4 dietary treatment groups (12 replicate cages of 12 birds). Dietary treatments were corn-soybean meal-based and included 1) control diet + sham-inoculated (Ucon), 2) control diet + Eimeria oocyst challenge (Icon), 3) control diet with 250 mg/kg Yucca-derived saponin product + Eimeria oocyst challenge (ISap250), and 4) control diet with 500 mg/kg of Yucca-derived saponin product + Eimeria oocyst challenge (ISap500). On study day 14, birds were orally inoculated with 1.5 mL of tap water containing Eimeria acervulina, E. maxima, and E. tenella (100,000, 40,000, and 30,000 oocysts/dose, respectively), or sham-inoculated with 1.5 mL of tap water. Eimeria-challenged birds exhibited a reduction in growth compared with uninfected birds (P < 0.001); however, there were no detectable differences due to dietary treatment among Eimeria-challenged groups. Mucosal thickness in the jejunum was increased (P < 0.042) in all infected groups and there were no differences among infected groups; however, saponin supplementation included at 250 mg/kg was not significantly different from the uninfected birds. Lymphocytes as a percentage of total white blood cells were increased (P < 0.014) in all Eimeria-challenged groups at 7 D post-inoculation compared with uninfected birds, but birds supplemented at 250 mg/kg were not different from uninfected birds. Cecal and duodenal IFN-γ expression increased with infection when compared with sham-inoculated birds. Cecal and duodenal IL-1β expression increased (P < 0.008 and P < 0.039) due to infection, and ISap250 and ISap500 treatments ameliorated IL-1β expression to levels not different from sham-inoculated birds. These results suggest that saponin supplementation may provide some immunomodulatory effects during a mixed coccidian challenge as evidenced by lymphocyte responses, changes in intestinal structure, and alterations in cecal and duodenal inflammatory cytokine mRNA expression.
Utility of Feed Enzymes and Yeast Derivatives in Ameliorating Deleterious Effects of Coccidiosis on Intestinal Health and Function in Broiler Chickens.
Kiarie Elijah G,Leung Haley,Akbari Moghaddam Kakhki Reza,Patterson Rob,Barta John R
Frontiers in veterinary science
Coccidiosis induced necrotic lesions impair digestive capacity and barrier function in concurrence with increased risks for secondary bacterial infections. The industry has been successful in controlling coccidiosis with anticoccidials and vaccination. However, concerns over species resistant to anticoccidials, gaps in vaccination and restriction on antibiotics is stimulating research and application of alternative and/or complimentary strategies for coccidiosis control. The aim of this paper is to appraise literature on the utility of feed enzymes and yeast derivatives in modulating coccidiosis. Feed enzymes can complement endogenous enzymes (protease, amylase, and lipase) that may become insufficient in coccidiosis afflicted birds. Coccidiosis in the upper small intestine creates conditions that enhances efficacy of phytase and there are reports indicating supplemental phytase can mitigate the negative impact of coccidiosis on bone quality. Increase in intestinal short chain fatty acids due supplemental fiber degrading enzymes has been linked with reduced survivability of . There is evidence whole yeast (live or dead) and derivatives can modulate coccidiosis. Immunomudulation properties of the yeast derivatives have been shown to enhance cellular and humoral immunity in challenge models which is critical for effectiveness of coccidial vaccination. Moreover, yeast nucleotides have been shown to be beneficial in stimulating healing of intestinal mucosal surface. Other novel work has shown that certain yeast cells can produce derivatives with anticoccidial compounds effective in attenuating oocysts shedding. Yeast cell surface has also been shown to be an effective oral vaccine delivery vehicle. Overall, while further refinement research is warranted to address inconsistencies in responses and commercial application, there is evidence feed enzymes and yeast derivatives could complement strategies for maintaining intestinal function to bolster growth performance in broilers compromised with coccidiosis. However, broilers receive diets containing several feed additives with distinct mode of actions and yet there is dearth of empirical data on the expected responses.Future evaluations should consider combinations of additives to document animal responses and potential synergies.
Effects of Bacillus subtilis and zinc on the growth performance, internal organ development, and intestinal morphology of male broilers with or without subclinical coccidia challenge.
Wang Xi,Kiess Aaron S,Peebles E David,Wamsley Kelley G S,Zhai Wei
Effects of antibiotic (bacitracin), anticoccidial (narasin), and alternative (Bacillus subtilis and zinc) feed additives on growth performance, internal organ development, and intestinal morphology of commercial broilers with or without subclinical coccidia challenge were determined. A total of 1,344 1-day-old male Ross × Ross 708 broilers were randomly distributed into 12 treatments (6 diets × 2 challenge treatments, 8 replication pens/treatment) in 96 floor pens. The 6 dietary treatments were as follows: a control diet (corn and soybean-meal basal diet), a probiotic diet (basal diet + Bacillus subtilis), a zinc diet (basal diet + 100 ppm zinc), a probiotic and zinc combined diet, an anticoccidial diet (basal diet + narasin), and a practical diet (basal diet + narasin + bacitracin). On day 21, each chick in the challenge treatment was gavaged with a 10× dose of a commercial vaccine containing live Eimeria oocytes, whereas each chick in the non-challenge treatment was gavaged with equivalent distilled water. The subclinical coccidia challenge increased the relative weights of pancreas and decreased the ileal crypt depth of broilers at 26 d of age, increased feed conversion ratios from day 15 to 28 and 29 to 40, and increased the relative weights of duodenum and bursa on day 54. As compared to other diets, anticoccidial and practical diets increased BW gain and decreased feed conversion ratio from day 15 to 28, and increased the day 40 carcass weights. As compared to control diets, probiotic diets decreased BW gain and increased the mortality from day 15 to 28; however, probiotic diets did not affect the overall growth performance from day 0 to 54 or carcass yield on day 54. Growth measurements during periods of day 29 to 40 and day 41 to 54 were not affected by any feed additive. From this study, a subclinical coccidia challenge enlarged specific internal organs and compromised the feed conversion ability of broilers. Dietary Bacillus subtilis did not affect overall growth rate or carcass yield of broilers under subclinical coccidia challenge.
The impact of β-glucans on performance and response of broiler chickens during a coccidiosis challenge.
Ott C P,Omara I I,Persia M E,Dalloul R A
Coccidiosis is a costly parasitic disease to the poultry industry with multiple prevention methods being explored to control its impact. This study evaluated the feeding effects of β-glucans on performance and responses of chickens during a coccidiosis challenge. Cobb 500 male broilers (n = 1280) were assigned to 1 of 8 treatment groups (8 replicate pens; 20 birds/pen) in a 2 × 4 factorial arrangement, including non-infected and Eimeria-infected birds fed for 28 d a control diet, control + BG (150 g/MT Algamune 50), control + BGZn (100 g/MT Algamune 50 Zn), and control + 0.01% Salinomycin (Sal). On d15, birds in the challenge groups received a mixed Eimeria inoculum. Birds and feed were weighed weekly on a per pen basis to evaluate body weight gain (BWG), feed intake (FI), and feed conversion ratios (FCR). Lesion scores were assessed 6 d post infection (d21) on 3 birds per pen. Performance data were subjected to ANOVA and differences were established using the LS-MEANS statement with significance reported at P ≤ 0.05. There were minor differences in lesion scores among the dietary treatments in the infected groups with reduced duodenal and cecal scores in the Sal group compared to the BGZn and BG groups, respectively. The coccidiosis challenge main effect resulted in a significant reduction in 0-28 d BW and FI. Dietary treatment resulted in non-significant effect on BWG, but Sal addition resulted in increased FI. A significant diet X challenge interaction resulted in higher FCR in the Eimeria-challenged birds supplemented with Sal and BGZn in comparison to the other challenged groups, likely due to reduced mortality in the challenged Sal and BGZn groups. Body composition analysis at d28 revealed that the Eimeria challenge reduced both fat and lean tissue contents, where the β-glucans and Sal birds had lower fat percent than control birds.
Phenotypic and genetic variation in the response of chickens to Eimeria tenella induced coccidiosis.
Boulton Kay,Nolan Matthew J,Wu Zhiguang,Psifidi Androniki,Riggio Valentina,Harman Kimberley,Bishop Stephen C,Kaiser Pete,Abrahamsen Mitchell S,Hawken Rachel,Watson Kellie A,Tomley Fiona M,Blake Damer P,Hume David A
Genetics, selection, evolution : GSE
BACKGROUND:Coccidiosis is a major contributor to losses in poultry production. With emerging constraints on the use of in-feed prophylactic anticoccidial drugs and the relatively high costs of effective vaccines, there are commercial incentives to breed chickens with greater resistance to this important production disease. To identify phenotypic biomarkers that are associated with the production impacts of coccidiosis, and to assess their covariance and heritability, 942 Cobb500 commercial broilers were subjected to a defined challenge with Eimeria tenella (Houghton). Three traits were measured: weight gain (WG) during the period of infection, caecal lesion score (CLS) post mortem, and the level of a serum biomarker of intestinal inflammation, i.e. circulating interleukin 10 (IL-10), measured at the height of the infection. RESULTS:Phenotypic analysis of the challenged chicken cohort revealed a significant positive correlation between CLS and IL-10, with significant negative correlations of both these traits with WG. Eigenanalysis of phenotypic covariances between measured traits revealed three distinct eigenvectors. Trait weightings of the first eigenvector, (EV1, eigenvalue = 59%), were biologically interpreted as representing a response of birds that were susceptible to infection, with low WG, high CLS and high IL-10. Similarly, the second eigenvector represented infection resilience/resistance (EV2, 22%; high WG, low CLS and high IL-10), and the third eigenvector tolerance (EV3, 19%; high WG, high CLS and low IL-10), respectively. Genome-wide association studies (GWAS) identified two SNPs that were associated with WG at the suggestive level. CONCLUSIONS:Eigenanalysis separated the phenotypic impact of a defined challenge with E. tenella on WG, caecal inflammation/pathology, and production of IL-10 into three major eigenvectors, indicating that the susceptibility-resistance axis is not a single continuous quantitative trait. The SNPs identified by the GWAS for body weight were located in close proximity to two genes that are involved in innate immunity (FAM96B and RRAD).
Evaluation of encapsulated sodium butyrate with varying releasing times on growth performance and necrotic enteritis mitigation in broilers.
Liu J D,Lumpkins B,Mathis G,Williams S M,Fowler J
This study was conducted to evaluate the effect of an encapsulated sodium butyrate (Na-B) with targeted releasing times on growth performance and mitigating the impact of necrotic enteritis in broilers. Two Na-B (30% of Na-B content) products, CMA (2 h releasing time) and CMP (3 to 4 h releasing time), were evaluated in a necrotic enteritis challenge model. The experiment consisted of 4 Na-B treatments (500 and 1,000 ppm of each product) plus 2 control (non-challenged and challenged). A total of 336 Cobb-Cobb male broilers were placed 8 birds per pen into 7 replicate battery cages. On day 14, birds from challenged treatments were orally gavaged with ∼5,000 oocysts of Eimeria maxima. On day 19, 20, and 21, the challenged birds received 1 mL of 108 cfu/mL Clostridium perfringens. Total pen body weight (BW) and feed weight were assessed on day 14, 21, and 28 for BW gain and mortality-adjusted feed conversion ratio (FCR). On day 21, 3 birds were randomly selected per pen and scored for intestinal lesions. The duodenum and jejunum tissue were collected on day 21 and 28 for quantifying intestinal histology. Results revealed that adding CMA at 500 ppm showed significantly higher cumulative BW gain (P < 0.05) compared to the challenged control from day 1 to 21. Adding CMA at 500 ppm also showed the equivalent cumulative FCR that was comparable to the non-challenged control on day 21. The CMA treatments and CMP at 1,000 ppm treatment showed equivalent BW gain compared to the non-challenge control after an additional 7 d post-challenge on day 28. Both products at 500 or 1,000 ppm had the significantly (P < 0.05) lower intestinal lesion scores compared to the challenged control. However, there was no difference in lesion scores among the Na-B treatments. The Na-B product targeted to release in the anterior intestinal tract shows the beneficial effects on BW gain and feed utilization efficiency in current challenge model. Adding encapsulated Na-B product has the potential to mitigate the impact of necrotic enteritis in broilers.
Bacillus amyloliquefaciens CECT 5940 alone or in combination with antibiotic growth promoters improves performance in broilers under enteric pathogen challenge.
de Oliveira Marllon José Karpeggiane,Sakomura Nilva Kazue,de Paula Dorigam Juliano Cesar,Doranalli Kiran,Soares Letícia,Viana Gabriel da Silva
A study was conducted to investigate the effects of Bacillus amyloliquefaciens CECT 5940 as a direct-fed microbial (DFM) alone or in association with bacitracin methylene disalicylate (BMD) in broilers under enteric pathogen challenge. A total of 1,530-day-old male Cobb500 chicks were randomly assigned to 5 treatments, with 9 replicate pens with 34 birds each. Treatments included positive control (PC, basal diet without additives or challenge); negative control (NC, basal diet without additive and challenged birds); NC + 0.05 g/kg BMD; NC + 1 g/kg DFM (106 CFU B. amyloliquefaciens CECT 5940/g of feed); and NC + 0.05 g/kg BMD + 1 g/kg DFM. The challenge consisted of oral gavage with Eimeria maxima and Clostridium perfringens inoculum. Body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were evaluated on days 21, 35, and 42. Ileal and cecal content were collected on days 21 and 28 for C. perfringens enumeration by real-time PCR assay and the intestinal health was evaluated by scores. Uniformity (UN), carcass (CY), and breast meat yields (BMY) were evaluated on day 42. After 14 and 21 d post-inoculation, birds in the challenged groups had significant lower FI and BWG compared to the PC group (P < 0.05). However, the groups receiving DFM, BMD, or its combination presented better FCR, CY, BMY, UN, and lower incidence of footpad lesion and litter quality visual scores, compared to the NC group without feed additives (P < 0.05). Mortality was not affected by treatments (P > 0.05). Broilers fed DFM, BMD, or its combination presented lower C. perfringens in ileal content at 21 and 28 d compared to NC group without additives (P < 0.05) and also maintained gut health by keeping the frequency of ballooning, abnormal content, and swollen mucosa comparable to the PC group (P > 0.05). The study indicates that Bacillus amyloliquefaciens CECT 5940 is effective as BMD to provide similar performance and gut health in challenged broilers.
Effects of reducing growth rate via diet dilution on bone mineralization, performance and carcass yield of coccidia-infected broilers.
Oikeh Idiegberanoise,Sakkas Panagiotis,Taylor James,Giannenas Ilias,Blake Damer P,Kyriazakis Ilias
Coccidiosis and rapid growth rate (GR) compromise bone mineralization in modern broilers. We tested the hypothesis that reducing GR via diet dilution during peak bone development will improve bone mineralization in both infected and uninfected broilers. A total of 384 male Ross 308 chicks were allocated to a basal grower diet (3,107 kcal/kg ME and 19.4% CP) diluted with 0, 5, 10, or 15% lignocellulose (n = 12 pens/treatment, 8 birds/pen) at day 10 of age. Prior to this, birds in each group received half the intended diet-dilution levels (day 8 to 10 of age) and a common starter diet (day 1 to 7 of age). At day 13 of age (day 0 post-infection, pi), birds were orally inoculated with either 7,000 sporulated Eimeria maxima oocysts (I) or water (C), forming a 4 diet-dilution level × 2 infection status factorial experiment. Performance was measured over 12 days pi and scaled to BW at infection (day 0 pi) to account for a priori BW differences. At day 12 pi (day 25 of age), 1 bird/pen (a total of 6 birds/treatment) was sampled to assess tibia and femur mineralization relative to BW, and carcass yield. There was no interaction (P > 0.05) between infection status and diet-dilution level on ADFI/BW measured over day 1 to 12 pi, or on any bone variable. ADG/BW pi decreased (P < 0.01) with diet dilution amongst C birds, but was statistically similar (P > 0.05) amongst I birds. I compared to C birds had reduced breast meat (P < 0.05) and eviscerated carcass yield (P < 0.01), femur (P < 0.05) and tibia (P < 0.01) breaking strength (BS), and femur ash weight (AW) (P < 0.05). Diet dilution did not affect carcass yield, but improved femur BS (P < 0.001), and tended to improve (P < 0.1) femur and tibia AW. Overall, diet dilution significantly affected femur, more than tibia, variables: relative BS, robusticity index, and ash percentage. Reducing GR affected broiler long bone mineralization to a similar degree in the presence or absence of coccidiosis.
Effects of coccidial vaccination and dietary antimicrobial alternatives on the growth performance, internal organ development, and intestinal morphology of Eimeria-challenged male broilers.
Wang Xi,Peebles E David,Kiess Aaron S,Wamsley Kelley G S,Zhai Wei
Effects of the coccidial vaccination and dietary antimicrobial alternatives on growth performance, internal organ development, and intestinal morphology of male broilers subjected to an Eimeria challenge were determined. A total of 1,120 one d-old Ross × Ross 708 male broilers were randomly distributed to 80 floor pens (10 treatments, 8 replication pens/treatment, and 14 chicks/pen). A 2 × 5 factorial arrangement of treatments was used to determine the main and interaction effects of the coccidial vaccination (vaccinated or non-vaccinated) and the dietary additive [1) corn and soybean-meal basal diet, 2) basal diet + antimicrobials (bacitracin and salinomycin), 3) basal diet + probiotics (3 Bacillus subtilis strains), 4) basal diet + prebiotics (mannan-oligosaccharides and β-glucans), and 5) basal diet + probiotics + prebiotics]. To mimic the Eimeria challenge, all chicks were gavaged with a 20x dose of a different coccidial vaccine (live Eimeria oocysts) at Day 14. The coccidial vaccination decreased Day 0-14 and 29-42 BW gain (BWG) and subsequently decreased Day 0-56 BWG. Broilers fed diets with antimicrobials exhibited the lowest feed conversion ratio (FCR) during the periods of Day 0-14 and 15-28, the shallowest ileal crypt depth on Day 28, and the lowest relative duodenum weight on Day 28 and 42. The Pre+Pro diets helped the broilers to reach a lower overall FCR than did the Pro alone diets and helped the broilers reach a FCR similar to that of the Anti diets. However, broilers fed diets supplemented with prebiotics and probiotics exhibited the deepest intestinal crypt depth on Day 28. There was no interaction between coccidial vaccination and dietary additive on growth performance or any carcass yield. In conclusion, antimicrobial additives might reduce the intestinal size of broilers; whereas prebiotic and B. subtilis-based probiotic additives might promote the growth of several digestive organs. Prebiotics can be safely used with B. subtilis-probiotics in broiler feed without compromising feed conversion ability.
Dietary supplementation with free methionine or methionine dipeptide improves environment intestinal of broilers challenged with Eimeria spp.
Khatlab Angélica de Souza,Del Vesco Ana Paula,Rodrigues Oliveira Neto Adhemar,Almeida Fernanda Losi Alves,Gasparino Eliane
Journal of animal science
This study examined the influence of a diet enriched with free methionine (dl-Met) or methionine dipeptide (dl-MMet) on the intestinal health of Eimeria-challenged (EC) and unchallenged (UC) broilers. A non-supplemented, methionine-deficient diet (NS) was used as control. Treatments were arranged in a 2 × 3 factorial completely randomized design with eight replications. Broilers in the EC group were infected with sporulated oocysts of Eimeria spp. (E. acervulina, E. maxima, E. praecox, and E. mitis) at 14 d of age. Performance analysis, light and electron microscopy of the jejunum, analysis of genes related to apoptosis and cell proliferation in the jejunum, and blood tests were performed at 6 days post-inoculation (dpi). EC broilers had poorer performance than UC broilers, regardless of diet (P < 0.001). Broilers fed the dl-Met diet had greater weight gain (P = 0.004) and lower feed conversion ratio (P = 0.019) than broilers fed other diets. Jejunal sections from EC broilers fed the NS diet showed short (P = 0.001) and wide villi (P < 0.001) with increased crypt depth (P < 0.001) and reduced villus / crypt ratio (P = 0.001), jejunal absorptive surface area (P < 0.001), number of neutral goblet cells (Eimeria challenge: P = 0.048; diet P = 0.016), and mucin 2 (MUC2) gene expression (P = 0.018). EC birds fed the dl-MMet diet had higher enterocyte height (P < 0.001). Birds fed the dl-MMet diet had low lamina propria width (P = 0.009). UC broilers fed the dl-Met diet had the highest number of acidic goblet cells (P = 0.005), whereas EC broilers assigned the dl-MMet diet showed the highest number of intraepithelial lymphocytes (P = 0.033). Reduced expression of caspase-3 (CASP3) (P = 0.005), B-cell lymphoma 2 (BCL2) (P < 0.001), mechanistic target of rapamycin (MTOR) (P < 0.001), and ribosomal protein S6 kinase B1 (RPS6KB1) (P < 0.001) genes was observed in EC animals. MTOR expression levels were highest in birds fed the dl-MMet diet (P = 0.004). Plasma activities of aspartate aminotransferase (AST) was influenced by both diet (P = 0.002) and Eimeria challenge (P = 0.005), with EC broilers assigned the NS diet showing the highest levels. EC broilers fed the NS diet had higher creatine kinase (CK) activity (P = 0.049). EC broilers had lower plasma uric acid (P = 0.004) and higher serum mucoproteins level (P < 0.001). These results indicate that methionine dipeptide supplementation is able to mitigate the harmful intestinal effects of Eimeria spp. in broilers.
Influence of coccidiosis vaccination on nutrient utilization of corn, soybean meal, and distillers dried grains with solubles in broilers.
Gautier A E,Rochell S J
Two experiments were conducted to determine the impact of coccidiosis vaccination on the apparent ileal digestibility (AID) of nutrients and ileal digestible energy (IDE) in commonly used feed ingredients in broilers. Eight experimental treatments based on a factorial arrangement of coccidiosis vaccination (control with in-feed diclazuril [CTL] or vaccinated [VAC]) and 4 different diets were administered to male Cobb 500 broilers in floor pens containing 12 birds per pen. For the vaccinated group, a 3× dose of a live coccidiosis vaccine was given via oral gavage on the day of hatch. Experimental diets consisted of a basal diet and 3 test diets in which 30% of the basal diet was replaced with either corn, soybean meal (SBM), or distillers dried grains with solubles (DDGS) to allow for calculation of nutrient digestibility of individual ingredients by difference. Broilers were fed a common diet from 0 to 7 D and experimental diets from 7 to 12 D. On day 12, blood and ileal digesta were collected to measure plasma carotenoids and determine AID of nitrogen, ether extract, IDE (experiments 1 and 2), and amino acids (AA) (experiment 2). Vaccination increased (P < 0.05) excreta oocyst counts and decreased (P < 0.05) plasma carotenoids when compared with CTL birds. Interactive effects (P < 0.05) were observed for AID of nitrogen (experiment 1) which was reduced by vaccination in birds fed the corn diet and increased for birds fed DDGS. No differences (P > 0.05) in IDE were observed between VAC and CTL birds in either experiment, whereas vaccination decreased (P < 0.05) AID of ether extract independently of diet. Interactive effects (P < 0.05) were observed for AA digestibility, whereby digestibility of all AA was reduced by VAC in corn diets but generally increased AA digestibility of DDGS diets, with minimal impact on SBM diets. In conclusion, the impact of coccidiosis vaccination on nutrient and energy digestibility varied among ingredients; however, digestibility was minimally impacted or improved with DDGS.
Evaluation of optimum conditions for decoquinate nanoliposomes and their anticoccidial efficacy against diclazuril-resistant Eimeria tenella infections in broilers.
Bo Ruonan,Dai Xingru,Huang Jie,Wei Simin,Liu Mingjiang,Li Jingui
Decoquinate (DQ) is used for prophylaxis against coccidian infections within the digestive tract of chickens, but DQ is extremely insoluble in water. Hence, improving the water solubility of DQ is extremely important. First, decoquinate nanoliposomes (DQNLs) were prepared by the thin-film dispersion-ultrasonic method. The preparation conditions of DQNLs were optimized using the orthogonal test. The optimal preparation conditions of DQNLs were: a ratio of egg-yolk lecithin:drug (w/w) of 10:1, ratio of egg-yolk lecithin:cholesterol (w/w) of 5:1, rotary-evaporation temperature of 50 ℃, and ultrasound duration of 15 min. The encapsulation efficiency of DQNLs prepared under these conditions reached 99.24 % and drug loading was 5.67 %. The characterization of optimized DQNLs was also done. Transmission electron microscopy of DQNLs showed that they had the characteristic structure of liposomes. The mean particle size was 115.6 nm. The polydispersity index was 0.175. The zeta potential was -39.1 mV. The stability of DQNLs was high upon storage at 4 ℃. In vivo studies demonstrated that the lower dose (5 mg/L) of DQNLs in drinking water obtained the similar anticoccidial efficacy to that of 40 mg/kg DQ in feed against diclazuril-resistance Eimeria tenella isolate. The in vitro inhibitory effect of DQNLs on the sporulation of Eimeria tenella oocysts was dose-dependent. Therefore, the anticoccidial efficacy of DQ was enhanced significantly after being encapsulated into nanoliposomes.
Effects of Eimeria tenella infection on chicken caecal microbiome diversity, exploring variation associated with severity of pathology.
Macdonald Sarah E,Nolan Matthew J,Harman Kimberley,Boulton Kay,Hume David A,Tomley Fiona M,Stabler Richard A,Blake Damer P
Eimeria species cause the intestinal disease coccidiosis, most notably in poultry. While the direct impact of coccidiosis on animal health and welfare is clear, its influence on the enteric microbiota and by-stander effects on chicken health and production remains largely unknown, with the possible exception of Clostridium perfringens (necrotic enteritis). This study evaluated the composition and structure of the caecal microbiome in the presence or absence of a defined Eimeria tenella challenge infection in Cobb500 broiler chickens using 16S rRNA amplicon sequencing. The severity of clinical coccidiosis in individual chickens was quantified by caecal lesion scoring and microbial changes associated with different lesion scores identified. Following E. tenella infection the diversity of taxa within the caecal microbiome remained largely stable. However, infection induced significant changes in the abundance of some microbial taxa. The greatest changes were detected in birds displaying severe caecal pathology; taxa belonging to the order Enterobacteriaceae were increased, while taxa from Bacillales and Lactobacillales were decreased with the changes correlated with lesion severity. Significantly different profiles were also detected in infected birds which remained asymptomatic (lesion score 0), with taxa belonging to the genera Bacteroides decreased and Lactobacillus increased. Many differential taxa from the order Clostridiales were identified, with some increasing and others decreasing in abundance in Eimeria-infected animals. The results support the view that caecal microbiome dysbiosis associated with Eimeria infection contributes to disease pathology, and could be a target for intervention to mitigate the impact of coccidiosis on poultry productivity and welfare. This work highlights that E. tenella infection has a significant impact on the abundance of some caecal bacteria with notable differences detected between lesion score categories emphasising the importance of accounting for differences in caecal lesions when investigating the relationship between E. tenella and the poultry intestinal microbiome.
Eimeria tenella oocysts attenuated by low energy electron irradiation (LEEI) induce protection against challenge infection in chickens.
Thabet Ahmed,Schmäschke Ronald,Fertey Jasmin,Bangoura Berit,Schönfelder Jessy,Lendner Matthias,Ulbert Sebastian,Daugschies Arwid
In vitro and in vivo studies were performed to assess whether Eimeria tenella (E. tenella) oocysts, exposed to low energy electron irradiation (LEEI), might be considered potential vaccine candidates against cecal coccidiosis. Sporulated oocysts were exposed to LEEI of 0.1 kGy to 10.0 kGy. Reproduction inhibition assays (RIA) were performed in MDBK cells to assess infectivity of sporozoites excysted from irradiated and non-irradiated oocysts. LEEI of 0.1 kGy or 0.5 kGy resulted in 73.2% and 86.5% inhibition of in vitro reproduction (%I), respectively. Groups of 12 one day old (D1) chicken were orally inoculated with Paracox®-8 (G1), 2.0 × 10 non-irradiated oocysts (G2) or 1.0 × 10 irradiated oocysts exposed to LEEI of 0.1 kGy (G3, G4) or 0.5 kGy (G5). Chicken of groups G1, G2, G4 and G5 were challenged 3 weeks later (D21) by a single inoculation of 7.5 × 10 non-attenuated oocysts of the same strain while G3 remained unchallenged. All chickens were subject to necropsy 7 days after challenge (D28) to estimate lesion scores (LS) and oocyst index (OI). A positive control (PC, non-vaccinated, challenged) and a negative control (NC, non-vaccinated, non-challenged) were kept in parallel. Chicken of group G5 had similar weight gain as the Paracox®-8 group (G1) after challenge and higher weight gains as compared to the other vaccinated groups. Feed conversion ratio (FCR) did not differ between chickens inoculated with oocysts irradiated with 0.5 kGy (G5) and negative control (NC) before challenge (1.25-1.52). After challenge FCR was 1.99 (G5) to 2.23 (G4) in the vaccinated chicken compared to 1.76 in group NC. LS and OI were significantly lower in all vaccinated groups as compared to group PC. Progeny oocysts collected from the feces of chickens following vaccination with irradiated oocysts exhibited lower in vitro infectivity/reproduction in MDBK cells with %I of 89.7% and 82.4% for progeny of oocysts irradiated with 0.5 kGy and 0.1 kGy, respectively, suggesting hereditary attenuation by LEEI treatment. Seroconversion was demonstrated by ELISA before challenge (D21) in all vaccinated groups, however, chicken inoculated with irradiated oocysts displayed higher antibody levels than those inoculated with precocious oocysts (G1). In Western blot analysis chicken vaccinated with virulent (G2) or 0.1 kGy-irradiated E. tenella oocysts (G3, G4) showed more protein bands compared to G5 (0.5 kGy). We conclude that LEEI could be a promising technology for production of attenuated oocyst vaccines.
A review of Eimeria antigen identification for the development of novel anticoccidial vaccines.
Venkatas J,Adeleke M A
Coccidiosis is a major poultry disease which compromises animal welfare and costs the global chicken industry a huge economic loss. As a result, research entailing coccidial control measures is crucial. Coccidiosis is caused by Eimeria parasites that are highly immunogenic. Consequently, a low dosage of the Eimeria parasite supplied by a vaccine will enable the host organism to develop an innate immune response towards the pathogen. The production of traditional live anticoccidial vaccines is limited by their low reproductive index and high production costs, among other factors. Recombinant vaccines overcome these limitations by eliciting undesired contaminants and prevent the reversal of toxoids back to their original toxigenic form. Recombinant vaccines are produced using defined Eimeria antigens and harmless adjuvants. Thus, studies regarding the identification of potent novel Eimeria antigens which stimulate both cell-mediated and humoral immune responses in chickens are essential. Although the prevalence and risk posed by Eimeria have been well established, there is a dearth of information on genetic and antigenic diversity within the field. Therefore, this paper discusses the potential and efficiency of recombinant vaccines as an anticoccidial control measure. Novel protective Eimeria antigens and their antigenic diversity for the production of cheap, easily accessible recombinant vaccines are also reviewed.
Preliminary study of the mechanism of action of ethanamizuril against Eimeria tenella.
Li Xueyan,Chen Huiya,Zhao Qiping,Zhang Lifang,Zhang Keyu,Wang Xiaoyang,Wang Mi,Liu Yingchun,Wang Chunmei,Xue Feiqun,Fei Chenzhong
Ethanamizuril (EZL) is a novel triazine compound with excellent anticoccidial activity. We carried out a preliminary investigation of the effects of EZL on the different life cycle stages of Eimeria tenella. EZL mainly acted on the schizogony stage, with peak activity during the second-generation merozoite stage. We also studied the possible target of EZL by identifying the majorly differentially expressed gene affected by EZL in second-generation merozoites using real-time polymerase chain reaction, and screening for surface antigen proteins (SAGs). The relative expression levels of SAGs were compared by Western blot analysis showing that expression levels of surface antigen family member (SAGfm) and SAG19 were significantly downregulated by EZL. Immunofluorescence analysis indicated that SAGfm and SAG19 were localized on the surface of second-generation merozoites. In addition, fluorescence signals were significantly stronger in second-generation merozoites of infected non-medicated control (INC) group compared with that of the EZL group. Therefore, it was speculated that SAGs might be a potential target of EZL action. The inhibitory effects of anticoccidial drugs on SAG levels in coccidia thus warrant further research.
Anti-coccidial effect of essential oil blends and vitamin D on broiler chickens vaccinated with purified mixture of coccidian oocyst from Eimeria tenella and Eimeria maxima.
Upadhaya Santi Devi,Cho Suk Hyeon,Chung Thau Kiong,Kim In Ho
A total of 800 1-day-old Ross 308 male broiler chicks were used in a 5-wk feeding trial to evaluate the effects of commercial feed additive that is composed of blends of essential oil (EO; CRINA Poultry, DSM) and vitamin D3. The birds were randomly assigned to 5 treatments with 10 replicate cages; each stocked with 16 birds and was fed corn-soybean-meal-based basal diet. Dietary treatments included: CON, unvaccinated birds fed basal diet/control; CCO, CON + coccidian oocysts vaccinated birds; EOD1, CCO + Essential oil blends and vitamin D/Prototype 1 (50 μg 25-OH-D3/kg diet, 15 mg CRINA Poultry/kg diet); EOD2, CCO + Prototype 2 (69 μg 25-OH-D3/kg diet, 30 mg CRINA Poultry/kg diet); and EOD3, CCO + Prototype 3 (138 μg 25-OH-D3/kg diet, 50 mg CRINA Poultry/kg diet). On day 7, all birds, except CON, were inoculated with 300 to 500 purified sporulated viable oocysts from Eimeria tenella and Eimeria maxima. As a result of this study, the supplementation of EO blends with vitamin D3 showed trends in improvement (P = 0.075) body weight gain (BWG) compared with CON and CCO during the grower phase (day 7 to 21). An increase (P < 0.05) in BWG and reduction (P < 0.05) in feed conversion ratio (FCR) were observed in birds fed EOD2 diet during day 21 to 35 compared with vaccinated birds without feed additive. The cumulative performance during overall period (day 1 to 35) also showed that BWG was increased and FCR was reduced in EOD2 and EOD3 compared with CON, CCO, and EOD1. Furthermore, the apparent total tract digestibility of dry matter tended (P = 0.06) to increase in EOD2 and EOD3 compared with CON and other treatments. The EOD2 and EOD3 treatments showed increased (P < 0.05) excreta Lactobacillus counts than EOD1. The intestinal lesion score induced by E. tennela in gastro-intestinal tract was lower (P < 0.05) in EOD1, EOD2, and EOD3 treatments compared with CCO. In conclusion, blends of EO and vitamin D3 could be used as anti-coccidial feed additive in broilers with coccidian infection.
Anticoccidial drugs of the livestock industry.
Noack Sandra,Chapman H David,Selzer Paul M
Coccidiosis is a parasitic disease of a wide variety of animals caused by coccidian protozoa. The coccidia are responsible for major economic losses of the livestock industry. For example, the annual cost due to coccidiosis to the global poultry industry has been estimated to exceed US$ 3 billion annually. Currently available drugs for the control of this disease are either polyether ionophorous antibiotics that are derived from fermentation products, or synthetic compounds, produced by chemical synthesis. Unfortunately, no new drugs in either category have been approved for use for decades. Resistance has been documented for all those of the drugs currently employed and therefore the discovery of novel drugs with unique modes of action is imperative if chemotherapy is to remain the principal means to control this disease. This chapter aims to give an overview of the efficacy and mode of action of the current compounds used to control coccidiosis in livestock and provides a brief outlook of research needs for the future.
Impact of dietary chitosan oligosaccharide and its effects on coccidia challenge in broiler chickens.
Osho S O,Adeola O
British poultry science
1. Two experiments were conducted, the first to determine the optimum inclusion of chitosan oligosaccharide (COS) in broiler diets to support growth performance, digestive functions, intestinal morphology, and immune organs. The second experiment evaluated the immune-protective properties of COS on broiler chickens during coccidia challenge (CC).2. Experiment 1 investigated the effect of graded dietary concentration of COS in the diets of broiler chickens using eight cage replicates for each of the six diets. A corn-soybean meal-based diet was used as the basal diet and supplemented with 0.0, 0.5, 1.0, 1.5, 2.0, or 2.5 g of COS/kg feed to form the six treatments.3. The diet supplemented with 1.0 g COS/kg of feed provided the optimal inclusion level for broiler chickens regarding body weight (BW) gain, jejunal villus height, villus height to crypt depth ratio, and ileal energy digestibility at d 22 of age.4. Experiment 2 investigated the immune-protective properties of COS in broiler chickens during CC. A total of 224 male broiler chicks were randomly assigned to eight replicate cages in a 2 × 2 factorial arrangement of treatments with two COS concentrations (0 or 1 g of COS/kg of diet), with or without CC.5. On d 18 of age, birds in the CC group received twice the recommended coccidia vaccine dose of 30 doses/kg BW.6. Coccidia challenge reduced (P < 0.05) and dietary COS increased (P < 0.05) BW gain, and feed intake. Dietary COS mitigated (P < 0.05) the CC-induced effects on gain:feed. Dietary COS supplementation attenuated the CC-induced effects (P < 0.05) on the expression of occludin genes.7. In conclusion, dietary COS improved performance, and the immune-related beneficial impact of COS supplementation was associated with reduced expression of pro-inflammatory cytokine genes.
Response of broiler chickens to dietary soybean bioactive peptide and coccidia challenge.
Osho S O,Xiao W W,Adeola O
Growth performance, nutrient digestibility, jejunal morphology, plasma cytokine, and gene expression responses of broiler chickens (Cobb 500) to graded concentrations of dietary soybean bioactive peptide (SBP) and coccidia challenge (CC) were investigated in 2 experiments. In experiment 1, 384 male broiler chicks were used to investigate the effect of graded dietary concentrations of SBP on growth performance, nutrient digestibility, and intestinal morphology in a randomized complete block design with 8 replicate cages and 6 diets. Corn-soybean meal-based diet was supplemented with 0, 1, 2, 3, 4, and 5 g of SBP/kg of diet. There were linear effects (P < 0.05) of graded concentrations of SBP on BW, BW gain, gain:feed, ileal villus height, and jejunal crypt depth at day 22 post hatching. There were linear effects (P < 0.01) of graded SBP concentrations on Ileal DM and energy digestibility. Experiment 2 was conducted to investigate the immune-protective properties of SBP on broiler chickens during a coccidia challenge. A total of 256 male broiler chicks were randomly assigned to 8 replicate cages in a 2 × 2 factorial arrangement of treatments with 2 SBP levels (0 or 4 g/kg of diet) and with or without CC. On day 14 post hatching, birds in the challenged group received 20×, which is twice the recommended coccidia vaccine dose of 25 doses/kg BW, whereas the non-challenged group received physiological saline. Dietary SBP ameliorated the CC-induced effect (P = 0.01) on gain: feed. Coccidia challenge reduced (P < 0.05) jejunal villi height, whereas dietary SBP supplementation increased (P < 0.05) jejunal villi height. Dietary SBP attenuated the CC-induced effects (P < 0.05) on the expression of plasma IL-1β, transforming growth factor-β, claudin-1, and occludin genes. In conclusion, dietary SBP improved growth performance, nutrient digestibility, and jejunal morphology. In addition, dietary SBP reduced the impact of coccidia challenge, and may be beneficial in the feed of broiler chickens for alleviation of health-related effects of coccidia infection.
Effect of functional oils on the immune response of broilers challenged with spp.
Moraes P O,Andretta I,Cardinal K M,Ceron M,Vilella L,Borille R,Frazzon A P,Frazzon J,Santin E,Ribeiro A M L
Animal : an international journal of animal bioscience
Infection with Eimeria sp. results in the activation of multiple facets of the host immune system; the use of phytogenics can modulate the inflammatory response and improve the performance of the challenged animal. The aim of this study was to evaluate the effect of a commercial blend of cashew nut shell liquid (CNSL) and castor oil on the immune response of broilers challenged with coccidiosis. A total of 864 one-day-old male chicks (Cobb 500) were randomly distributed into six treatment groups (8 pens/treatment and 18 chicks/pen) in a three-by-two factorial design with three additives: control (non-additive), 100 ppm of monensin or 0.15% CNSL-castor oil. Challenge status was determined twice at 14 days of age. Unchallenged birds were inoculated by gavage with oocysts sporulated with Eimeria tenella, Eimeria acervulina and Eimeria maxima. Although the positive control (non-additive and challenged) and CNSL-castor oil treatment groups exhibited similar variation in weight gain (ΔBWG) compared to unchallenged birds fed without additives, the variation observed in birds fed diets containing CNSL-castor oil was associated with a higher maintenance requirement and not feed efficiency. In the second week after infection, ΔBWG of the CNSL-castor oil treatment group did not significantly change compared to the other treatment groups. At days 7 and 14 post-challenge, there was a higher excretion of oocysts in the control group, whereas the CNSL-castor oil and monensin groups did not differ. The CNSL-castor oil group exhibited increased gene expression of interferon (IFN), interleukin 6 (IL-6) and tumor necrosis factor (TNF), while the control group exhibited increased expression of cyclooxygenase (COX) and IL-1. The heterophils/lymphocyte ratio was low for the monensin treatment group. The unchallenged birds that received monensin treatment presented higher gene expression of IFN, COX and IL-1 compared to the other treatments, while the CNSL-castor oil group exhibited reduced gene expression, except for TNF. The commercial blend of cashew nut liquid and castor oil modulated the inflammatory response against Eimeria spp. In the absence of the parasite, there was no stimulation of genes involved in the inflammatory response, demonstrating that the blend is an effective tool in specifically modulating the immune system of birds afflicted with coccidiosis.
Efficacy of probiotic Enterococcus faecium in combination with diclazuril against coccidiosis in experimentally infected broilers.
El-Sawah A A,Aboelhadid S M,El-Nahass E N,Helal H E,Korany A M,El-Ashram S
Journal of applied microbiology
AIMS:The study was conducted to investigate the combination of a probiotic strain of Enterococcus faecium and diclazuril to control coccidiosis in broilers. METHODS AND RESULTS:A total of 240 one-day-old female broiler chicks were divided into eight groups (30 chicks per group): prophylactic groups (G1, G2 and G3) and therapeutic groups (G4, G5 and G6) and two control groups (untreated infected, G7 and untreated uninfected, G8 controls). In the prophylactic approach, diclazuril alone (G1), probiotic alone (G2) or a mixture of both probiotic and diclazuril (G3) was orally administered to the chicks via drinking water 10 days prior to the infection. However, in the therapeutic approach, G4, G5 and G6 birds were administered diclazuril alone, probiotic alone and diclazuril+probiotic mix, respectively, in drinking water for five consecutive days after the appearance of clinical signs of coccidiosis. Birds of both approaches and G7 were experimentally infected with 25 × 10 Eimeria-sporulated oocysts. Chicks in G3 showed the highest weight gain, the lowest lesion score, a low oocyst count and mortality rate among the challenged groups. Moderate lesion scores and oocyst counts were observed in chickens administered probiotics prophylactically. In the therapeutic approach, broilers in G6 but not G5 displayed a decreased mortality rate and lesion score in comparison to those in G7 and G8. However, the result of the probiotic-treated group was not significantly different from that in the untreated infected control group. CONCLUSION:The probiotic supplementation as a prophylactic approach can decrease the adverse effects of eimerian infection. In addition, the probiotic and diclazuril mix achieved a considerable improvement in the growth performance. Therefore, probiotic plus diclazuril combination achieved a synergistic effect. SIGNIFICANCE AND IMPACT OF THE STUDY:Investigation into the synergism/antagonism between a probiotic and diclazuril as anticoccidial agent and the difference in the timing of administration.
Effects of Bacillus subtilis and coccidial vaccination on cecal microbial diversity and composition of Eimeria-challenged male broilers.
Wang Xi,Farnell Yuhua Z,Kiess Aaron S,Peebles E David,Wamsley Kelley G S,Zhai Wei
In a companion study, the effects of dietary antibiotic alternative and coccidial vaccination on the growth performance of male broilers have been reported. In this paper, the effects of dietary probiotics and coccidial vaccination on diversity and composition of cecal microbiota were investigated using a 3 (diets) × 2 (vaccinated or non-vaccinated) factorial setting of treatments. Three diets, including a corn and soybean-meal control diet, an antibiotic diet (a control diet supplemented with bacitracin and salinomycin), and a probiotic diet (a control diet supplemented with Bacillus subtilis) were provided to broiler chicken from day 0 to 42. To simulate an Eimeria challenge in the field, all chicks were gavaged with a 20× dose of commercial coccidial vaccine containing live Eimeria oocysts on day 14. Cecal contents were collected on day 42. High-throughput sequencing of the 16S rRNA gene was used to determine microbial diversity and composition. Coccidial vaccination to broilers reduced bacterial diversity (Shannon index) of the cecal microbiota. There was a significant interaction between the dietary additive and coccidial vaccination on the observed bacterial species number. Diets supplemented with B. subtilis increased bacterial species of non-vaccinated broilers but decreased bacterial species of vaccinated broilers. In contrast, diets supplemented with antibiotics reduced bacterial species of broilers from both groups. Interactions between dietary additive and coccidial vaccination were also observed on microbial composition. Vaccinated broilers fed the B. subtilis diet exhibited the lowest Firmicutes percentage and highest Bacteroidetes percentage within the microbial community. In addition, vaccinated broilers fed the B. subtilis diet exhibited the highest Rikenella microfusus percentage. From this study, the coccidial vaccination on the day of hatch reduced the microbial diversity of broilers at a later age. The inclusion of B. subtilis-probiotics in the feed of vaccinated broilers may reduce microbial diversity in cecal content by increasing the proportion of a predominant bacterial species, R. microfusus, in the microbial community.
Longitudinal Characterization of Coccidiosis Control Methods on Live Performance and Nutrient Utilization in Broilers.
Gautier Alyson E,Latorre Juan D,Matsler Phil L,Rochell Samuel J
Frontiers in veterinary science
An experiment was conducted to quantify the timing and magnitude of the effects of coccidiosis vaccination on the growth performance, apparent ileal digestibility (AID) of nutrients and energy, intestinal morphology, and plasma carotenoids and nitric oxide in broilers. Treatment groups consisted of 3 coccidiosis control methods [unvaccinated, unmedicated (NC), in-feed chemical coccidiostat (PC), and live oocyst vaccination (VAC) at day of hatch] administered to male Cobb broilers reared in floor pens. Body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were determined at 12, 16, 20, 28, and 36 d. Blood and ileal digesta were collected from birds in 10 replicate pens of each treatment at 12, 16, 20, and 36 d to evaluate plasma carotenoid and nitric oxide concentrations and determine nutrient AID and IDE. Jejunal samples were taken at 12, 20, and 36 d for morphological measurements. Oocyst shedding in VAC birds was confirmed by increased oocyst counts and decreased carotenoid concentrations ( < 0.05) when compared with PC birds, with no differences ( > 0.05) in nitric oxide concentrations. At 20 d, BWG and FI were lowest ( < 0.05) in VAC birds, intermediate in NC birds, and highest in PC birds, with no differences in FCR ( > 0.05). By 28 and 36 d, FCR was higher ( < 0.05) for VAC and NC birds but BWG and FI of VAC birds were similar ( > 0.05) to PC birds. At d 12, IDE and AID of nitrogen and ether extract were lower ( < 0.05) in VAC birds than PC birds. At d 16, AID of nitrogen was similar ( > 0.05) between PC and VAC birds, whereas AID of ether extract remained lower in VAC birds than PC birds. No differences in AID of nutrients or IDE were observed ( > 0.05) between VAC and PC birds at 20 or 36 d. No differences ( > 0.05) in jejunal morphology were observed at any time point. Overall, VAC elicited a transient reduction in AID and IDE, particularly for lipids, that diminished by d 20.
Comparative evaluation of herbal coccidiostat with chemotherapeutic coccidiostats on performance of broilers to control coccidiosis.
Srinivasu B,Preetam V Chinni,Gurram Srinivas,Reddy A Rajashekher
Tropical animal health and production
The objective of the present study was to investigate the comparative efficacy of recommended dose of selected anticoccidial drugs Salinomycin, Dinitolmide, while Cocciban at three dose levels on the performance of broilers. For this purpose, 420-day-old commercial male broiler chicks were randomly divided into 7 treatment groups with 10 replications of 6 birds each and reared in battery brooders up to 42 days of age. Groups were designated as uninfected unmedicated (T), infected unmedicated (T), Cocciban 500 g/ton and infected (T), Cocciban 750 g/ton and infected (T), Cocciban 1000 g/ton and infected (T), Salinomycin 500 g/ton and infected (T), and Dinitolmide and infected (T). Groups T, T, T, T, T, and T were experimentally infected at 21 days old by 50,000 oocysts of Eimeria species. The broilers were fed with starter (0-21 days) and finisher diets (22-42 days). The herbal product Cocciban 1000 g/ton alone had significantly (P < 0.05) higher body weight gain and feed efficiency than all other infected groups during the overall experimental period (0-42 days), but significantly lower than healthy control. All the groups did not show significant (P > 0.05) effect on mean feed intake, percent carcass yields and percent weights of liver, heart and gizzard. Similarly there was no significant (P < 0.05) influence of treatment groups on the organoleptic characteristics of meat. Treatment groups did not have any significant (P < 0.05) influence on humeral immune response to ND vaccine and cell-mediated immune response to PHA-P. Among all the infected groups, Cocciban 1000 g/ton group (78.33%) recorded more mean percent livability than all other infected groups.
The influence of indigestible protein on the performance and meat quality of broilers vaccinated for coccidiosis.
Bryan D D L S,Abbott D A,Classen H L
High dietary protein and the use of poorly digested protein sources have been suggested to negatively impact broiler health, possibly because of protein fermentation in the distal intestinal tract. The effect of dietary protein levels with low or high indigestible protein fractions (LIP or HIP) on male and female broiler performance were evaluated. The trial was completely randomized with a 2 × 3 × 2 factorial arrangement, where gender, dietary protein levels (24, 26, and 28%), and dietary protein digestible fractions were the main factors. Ross 308 male (1944) and female (2232) were allocated to 72 pens with 54 males or 62 females per pen. Six grower diets 24-LIP, 24-HIP, 26-LIP, 26-HIP, 28-LIP, and 28-HIP were fed from 0 to 32 D of age. Birds were vaccinated with Coccivac-B52 on day 5, and feed intake and BW were recorded on 0, 12, 22, and 32 D. On day 32, 24 birds per treatment were processed for meat yield. Males were heavier than females at all post-hatch ages and the LIP birds were heavier than their HIP counterparts on 32 D. On day 22, birds fed 24 and 26% CP were heavier than those fed 28% CP. Birds fed the 28-LIP diet consumed less total feed than their 24 and 26-LIP equivalents. Birds fed 24% CP had the highest total feed to gain ratio, whereas LIP fed birds had a lower total feed to gain than those fed HIP diets. LIP diets resulted in higher total mortality than the HIP diets. Carcass yield was higher for females than males, increased with CP level, and was lower in HIP than LIP birds. An interaction between CP level and protein digestibility resulted in the 26 and 28-LIP having higher breast yield than all other diets. In conclusion, broiler growth performance and meat yield were affected by dietary indigestible protein alone or in combination with gender and dietary CP level.
Comparison between a commercial blend of functional oils and monensin on the performance and microbiota of coccidiosis-challenged broilers.
Moraes P O,Cardinal K M,Gouvêa F L,Schroeder B,Ceron M S,Lunedo R,Frazzon A P G,Frazzon J,Ribeiro A M L
The aim of the study was to evaluate the effects of a cashew nut shell oil and commercial castor oil blend (CNSL-Castor oil) on the performance and microbiota of broiler chickens with and without coccidiosis challenge. A total of 864 one-day-old male chicks (Cobb) were randomly distributed to receive 6 treatments (8 pens/treatment; 18 chicks/pen) in a 3 × 2 factorial, with 3 additives (control [non-additives], 100 ppm sodium monensin, or 0.15% CNSL-Castor oil blend), and 2 levels of coccidiosis challenge at 14 D of age (unchallenged or inoculated by gavage with 1 mL of solution containing oocysts sporulated with Eimeria tenella, Eimeria acervulina, and Eimeria maxima). No differences in productive performance were observed among treatments in the pre-challenge period and in unchallenged birds (P > 0.05). Seven-days post-challenge, birds receiving monensin performed better than birds in the positive control group (non-additive and challenge) or in the CNSL-Castor oil group (P > 0.05). However, 14 D post-challenge, birds supplemented with CNSL-Castor oil presented higher weight gain and better feed conversion (P > 0.05), without any change in feed intake (P > 0.05). During the accumulated period (1 to 42 D of age), the live weight, weight gain, and feed intake did not differ between the CNSL-Castor oil and monensin groups, both of which presented higher values than the positive control. Lactobacillus spp. and Clostridium perfringens numbers were increased in the challenged birds (P < 0.05). CNSL-Castor oil supplementation reduced Clostridium cluster XIV, C. perfringens, and S. aureus, compared with the monensin and control groups (P > 0.05). In addition, the CNSL-Castor oil group presented the highest number of Lactobacillus spp. copies, followed by the monensin and positive control groups (P > 0.05). Thus, monensin and CNSL-Castor oil effectively minimized the impact of coccidiosis at different times. While monensin acts as an antimicrobial, CNSL-Castor oil modulates the intestinal microbiota with antimicrobial action against gram-positive bacteria, mainly C. perfringens and S. aureus.
Differential gene response to coccidiosis in modern fast growing and slow growing broiler genotypes.
Giles Tim,van Limbergen Tommy,Sakkas Panagiotis,Belkhiri Aouatif,Maes Dominiek,Kyriazakis Ilias,Mendez J,Barrow Paul,Foster Neil
We analysed intestinal tissues from groups of fast growing (Ross 308) broilers with natural or experimental coccidiosis, by genomic microarray. We identified genes that were differentially expressed (DE) in all groups and analysed expression of a panel of these, by qPCR, in Ross 308 and slow growing (Ranger classic) broilers, infected with 2500 or 7000 oocysts of Eimeria maxima for 6 or 13 days post-infection (dpi). Four genes (ADD3, MLLT10, NAV2 and PLXNA2) were upregulated (P <0.05) in Ross 308 but were not DE in Ranger Classic at 6 dpi with 2500 oocysts. Six genes (PTPRF, NCOR1, CSF3, SGK1, CROR and CD1B) were upregulated (P <0.05) in both Ross 308 and Ranger Classic infected with 2500 oocysts at 6 dpi but were not DE at 6 dpi with 7000 oocysts. At 13 dpi with 7000 oocysts, NAV2 and NCOR1 were upregulated in Ross 308 (P <0.05) and PTPRF was upregulated in both genotypes (P <0.05). DE of immune genes within the biomarker panel also occurred, with CSF3 upregulated in both genotypes infected with 2500 oocysts at 6 dpi and in Ranger Classic infected with 7000 oocysts, at 6 and 13 dpi (P <0.05). IL-22 was down-regulated in Ranger Classic infected with 2500 or 7000 oocysts at 6 dpi (P <0.05) but upregulated in both genotypes at 13 dpi (P <0.05). CD72 was down-regulated in Ranger Classic infected with 2500 oocysts at 6 dpi and with 7000 oocysts at 6 and 13 dpi (P <0.05). CD72 was upregulated in Ross 308 infected with 2500 oocysts at 6 dpi but was down-regulated following infection with 7000 oocysts at 13 dpi (P <0.05). In conclusion, differential gene expression occurs in fast and slow growing broiler genotypes with coccidiosis. In addition, we highlight a potential genetic biomarker panel for early diagnosis of coccidiosis.
Anticoccidial effect of Piper sarmentosum extracts in experimental coccidiosis in broiler chickens.
Wang Dingfa,Zhou Luli,Li Wei,Zhou Hanlin,Hou Guanyu
Tropical animal health and production
To study the anticoccidial effect of Piper sarmentosum extracts (PSE) in experimental broiler coccidiosis, 270 one-day-old Wenchang broiler chickens were randomly assigned to six groups, each with three replicates (n = 15). The six groups were blank control group (BC), negative control group (NC), positive control group (PC), and another three PSE addition groups. Chickens in three control groups were fed a basal diet without PSE supplementation. Chickens in the three PSE addition groups were fed a basal diet supplemented with PSE at 100 (T100), 200 (T200), and 300 (T300) mg/kg of feed, respectively. At 15 days of age, chickens in group NC, PC, and three PSE addition groups were challenged with an oral dose of 1 × 10(5) Eimeria tenella oocysts each chick. Chickens in group PC were fed with diclazuril solution in water for 5 days after 48 h with oocysts inoculation. The results showed that PSE and diclazuril improved growth performance and significantly (P < 0.05) decreased oocysts per gram in inoculated broiler chickens. PSE and diclazuril significantly (P < 0.05) decreased nitric oxide at 6 and 9 days post-inoculation relative to the NC group, respectively. At 6 and 9 days post-inoculation, PSE supplementation at 200 mg/kg in the diet increased concentration of interleukin 2 (IL-2) and interferon gamma (IFN-γ) (P < 0.05). PSE supplementation at 200 mg/kg in the diet significantly (P < 0.05) increased mRNA expressions of IFN-γ and IL-2 in the cecum of chickens at 9 days post-inoculation relative to the BC and NC group. The current results showed the anticoccidial properties, and beneficial effect on intestinal mucosa damage of PSE in broiler chickens that had been challenged by coccidiosis.
Eimeria maxima-induced transcriptional changes in the cecal mucosa of broiler chickens.
Li Charles,Yan Xianghe,Lillehoj Hyun S,Oh Sungtaek,Liu Liheng,Sun Zhifeng,Gu Changqin,Lee Youngsub,Xianyu Zhezi,Zhao Hongyan
Parasites & vectors
BACKGROUND:Apicomplexan protozoans of the genus Eimeria cause coccidiosis, one of the most economically relevant parasitic diseases in chickens. The lack of a complete understanding of molecular mechanisms in the host-parasite interaction limits the development of effective control measures. In the present study, RNA sequencing (RNA-Seq) was applied to investigate the host mRNA profiles of the cecal mucosa collected at day 5 post-infection with Eimeria maxima (EM). RESULTS:Total RNA from cecal samples of the uninfected naïve control and the EM groups was used to make libraries, generating 354,924,372 and 356,229,250 usable reads, respectively, which were assembled into a total of 386,088 high-quality unigenes (transcripts) in Trinity software. RNA-Seq analysis of cecal samples in the two groups revealed 332 upregulated and 363 downregulated genes with significant differences (P ≤ 0.05), including several significant immune-related gene families, such as the major histocompatibility complex (MHC) class I alpha chain, granzyme A and immunoglobulin subtype genes among upregulated differentially expressed genes. In addition, a total of 60 clusters of differentiation (CD) molecular genes and 570 novel genes were found. The completeness of the assembled transcriptome was further assessed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, Gene ontology (GO), eggNOG and CAZy for gene annotation. The broad gene categories represented by the highly differentiated host genes suggested enrichment in immune responses, and downregulation in the metabolic pathway, MARK signaling pathway, vascular smooth muscle contraction, and proteins processing in endoplasmic reticulum after EM infection. CONCLUSIONS:Eimeria maxima induced statistically significant differences in the cecal mucosal gene expression of infected chickens. These findings provide new insights into the host-parasite interaction and enhance our understanding of the molecular mechanism of avian coccidiosis.