Isolation and characterization of Borrelia hermsii associated with two foci of tick-borne relapsing fever in California.
Fritz Curtis L,Bronson Lawrence R,Smith Charles R,Schriefer Martin E,Tucker James R,Schwan Tom G
Journal of clinical microbiology
Relapsing fever, caused by the spirochete Borrelia hermsii and transmitted by the soft tick Ornithodoros hermsi, is endemic in many rural mountainous areas of California. Between 1996 and 1998, 12 cases of relapsing fever associated with two exposure sites in northern California were investigated. Follow-up at exposure sites included collection of soft ticks and serum specimens from sylvatic rodents. Attempts to cultivate spirochetes were made through inoculation of patient blood into mice and by feeding Ornithodoros ticks on mice. Three isolates of B. hermsii were recovered from two blood specimens and one pool of ticks. The protein and plasmid profiles of the three isolates were comparable to those of previous B. hermsii isolates from the western United States. Western immunoblotting of patient sera demonstrated an expanding immunologic response to antigens within four distinct molecular weight regions by 3 to 4 weeks postonset. Antibody to B. hermsii was detected in sera from 4 of 11 yellow-pine chipmunks (Tamias amoenus); no other rodent species collected were seropositive.
Tick-borne relapsing fever.
Dworkin Mark S,Schwan Tom G,Anderson Donald E,Borchardt Stephanie M
Infectious disease clinics of North America
Each year, many residents of and visitors to endemic regions of the western United States are exposed to the tick vectors of tick-borne relapsing fever (TBRF), Ornithodoros hermsi, Ornithodoros turicata, or Ornithodoros parkeri. This disease is remarkable because the human host is unaware of the tick bite, usually becomes very ill, may experience an exacerbation of symptoms rather than improvement shortly after beginning appropriate treatment, and, despite often high numbers of the etiologic organism in the blood, rarely dies as a result of the illness. Although relapsing fever is acquired in many parts of the world, this article focuses primarily on knowledge about TBRF in North America.
Epidemiology of tick-borne borreliosis in Morocco.
Diatta Georges,Souidi Yassine,Granjon Laurent,Arnathau Céline,Durand Patrick,Chauvancy Gilles,Mané Youssouph,Sarih M'hammed,Belghyti Driss,Renaud François,Trape Jean-François
PLoS neglected tropical diseases
BACKGROUND:The presence in Morocco of Argasid ticks of the Ornithodoros erraticus complex, the vector of tick-borne relapsing fever (TBRF) in North Africa, has been known since 1919, but the disease is rarely diagnosed and few epidemiological data are available. METHODOLOGY/PRINCIPAL FINDINGS:Between 2006 and 2011, we investigated the presence of Ornithodoros ticks in rodent burrows in 34 sites distributed across Morocco. We also collected small mammals in 10 sites and we investigated TBRF in febrile patients in Kenitra district. The prevalence of Borrelia infections was assessed by nested PCR amplification in ticks and the brain tissue of small mammals, and by evaluation of thick blood films in patients. A high proportion of burrows were infested with ticks of the O. erraticus complex in all regions of Morocco, with a mean of 39.5% for the whole country. Borrelia infections were found in 39/382 (10.2%) of the ticks and 12/140 (8.6%) of the rodents and insectivores studied by PCR amplification, and 102 patients tested positive by thick blood film. Five small mammalian species were found infected: Dipodillus campestris, Meriones shawi, Gerbillus hoogstrali, Gerbillus occiduus and Atelerix algirus. Three Borrelia species were identified in ticks and/or rodents: B. hispanica, B. crocidurae and B. merionesi. CONCLUSIONS/SIGNIFICANCE:Tick populations belonging to O. erraticus complex are widely distributed in Morocco and a high proportion of ticks and small mammals are infected by Borrelia species. Although rarely diagnosed, TBRF may be a common cause of morbidity in all regions of Morocco.
Isolation and characterization of Borrelia parkeri in Ornithodoros parkeri (Ixodida: Argasidae) collected in Colorado.
Gage K L,Eggleston M E,Gilmore R D,Dolan M C,Montenieri J A,Tanda D T,Piesman J
Journal of medical entomology
This study describes the identification of Borrelia parkeri spirochetes in Colorado. Two isolates of B. parkeri (6230 and 6232) were recovered from Ornithodoros parkeri Cooley ticks collected at an inactive prairie dog town in Moffat County. Both isolates were partially characterized by sequencing and subsequent parsimony and neighbor-joining analyses of appropriate regions of the 16S ribosomal RNA, flagellin and P66 genes. Analyses of the 16S gene sequences from the Colorado isolates indicated that they were more closely related to B. parkeri and B. tucatae than to B. hermsii or the other species of Borrelia investigated in this study. Additional analyses of amino acid sequences for flagellin and P66, however, clearly demonstrated that isolates 6230 and 6232 were most closely related to B. parkeri. The possible significance of B. parkeri as an agent of human disease is discussed.
New World relapsing fever Borrelia found in Ornithodoros porcinus ticks in central Tanzania.
Mitani Harumi,Talbert Alison,Fukunaga Masahito
Microbiology and immunology
Ticks were collected from 8 houses in Mvumi Mission village, near Dodoma, Tanzania. All ticks were examined for Borrelia infestation by flagellin gene-based nested polymerase chain reaction. All houses were highly infested with ticks, and all ticks collected were of the Ornithodoros porcinus species. Fifty-one out of 120 ticks were infected with spirochetes, and a flagellin gene sequence comparison showed that most of the spirochetes belonged to Borrelia duttonii, which is the causative agent of tick-borne relapsing fever in East Africa. The rest of the spirochetes were quite different from B. duttonii and instead resembled the New World tick-borne relapsing fever borreliae. Phylogenetic analysis using 16S ribosomal RNA gene sequences also supported the interpretation that the spirochete was a Borrelia species distinct from previously described members of the genus.
Evidence of Bartonella spp. in Blood and Ticks (Ornithodoros hasei) of Bats, in French Guiana.
Davoust Bernard,Marié Jean-Lou,Dahmani Mustapha,Berenger Jean-Michel,Bompar Jean-Michel,Blanchet Denis,Cheuret Marie,Raoult Didier,Mediannikov Oleg
Vector borne and zoonotic diseases (Larchmont, N.Y.)
We screened blood from 59 bats from French Guiana for Bartonella spp. PCRs were positive for 13.6% and culture was positive in one Noctilio albiventris and one Pteronotus parnellii, as well as in Ornithodoros hasei ticks collected from bats. Two isolated strains represent possible two new species.
A survey of argasid ticks and tick-associated pathogens in the Peripheral Oases around Tarim Basin and the first record of Argas japonicus in Xinjiang, China.
Zhao Li,Lin Xiang-Mei,Li Fei,Li Kai-Rui,He Bo,Zhang Lu-Yao,Pan Jiao-Jiao,Wang Qiang-Rong,Gao Jia-Min,Johnson Nicholas,Yuan Xiang-Fen,Lv Ji-Zhou,Wu Shao-Qiang,Liu Yong-Hong
Argasid ticks (Acari: Argasidae) carry and transmit a variety of pathogens of animals and humans, including viruses, bacteria and parasites. There are several studies reporting ixodid ticks (Acari: Ixodidae) and associated tick-borne pathogens in Xinjiang, China. However, little is known about the argasid ticks and argasid tick-associated pathogens in this area. In this study, a total of 3829 adult argasid ticks infesting livestock were collected at 12 sampling sites of 10 counties in the Peripheral Oases, which carry 90% of the livestock and humans population, around the Tarim Basin (southern Xinjiang) from 2013 to 2016. Tick specimens were identified to two species from different genera by morphology and sequences of mitochondrial 16S rRNA and 12S rRNA were derived to confirm the species designation. The results showed that the dominant argasid ticks infesting livestock in southern Xinjiang were Ornithodoros lahorensis (87.86%, 3364/3829). Ornithodoros lahorensis was distributed widely and were collected from 10 counties of southern Xinjiang. Argas japonicus was collected from Xinjiang for the first time. In addition, we screened these ticks for tick-associated pathogens and showed the presence of DNA sequences of Rickettsia spp. of Spotted fever group and Anaplasma spp. in the argasid ticks. This finding suggests the potential role for Argas japonicus as a vector of pathogens to livestock and humans.
Detection of a novel Rickettsia sp. in soft ticks (Acari: Argasidae) in Algeria.
Lafri Ismail,Leulmi Hamza,Baziz-Neffah Fadhila,Lalout Reda,Mohamed Chergui,Mohamed Karakallah,Parola Philippe,Bitam Idir
Microbes and infection
Argasid ticks are vectors of viral and bacterial agents that can infect humans and animals. In Africa, relapsing fever borreliae are neglected arthropod-borne pathogens that cause mild to deadly septicemia and miscarriage. It would be incredibly beneficial to be able to simultaneous detect and identify other pathogens transmitted by Argasid ticks. From 2012 to 2014, we conducted field surveys in 4 distinct areas of Algeria. We investigated the occurrence of soft ticks in rodent burrows and yellow-legged gull (Larus michahellis) nests in 10 study sites and collected 154 soft ticks. Molecular identification revealed the occurrence of two different soft tick genera and five species, including Carios capensis in yellow-legged gull nests and Ornithodoros occidentalis, Ornithodoros rupestris, Ornithodoros sonrai, Ornithodoros erraticus in rodent burrows. Rickettsial DNA was detected in 41/154, corresponding to a global detection rate of 26.6%. Sequences of the citrate synthase (gltA) gene suggest that this agent is a novel spotted fever group Rickettsia. For the first time in Algeria, we characterize a novel Rickettsia species by molecular means in soft ticks.
Borrelia crocidurae in Ornithodoros ticks from northwestern Morocco: a range extension in relation to climatic change?
Souidi Yassine,Boudebouch Najma,Ezikouri Sayeh,Belghyti Driss,Trape Jean-François,Sarih M'hammed
Journal of vector ecology : journal of the Society for Vector Ecology
Tick-borne relapsing fever (TBRF) is caused by Borrelia spirochetes transmitted to humans by Argasid soft ticks of the genus Ornithodoros. We investigated the presence of Ornithodoros ticks in rodent burrows in nine sites of the Gharb region of northwestern Morocco where we recently documented a high incidence of TBRF in humans. We assessed the Borrelia infection rate by nested PCR and sequencing. All sites investigated were colonized by ticks of the Ornithodoros marocanus complex and a high proportion of burrows (38.4%) were found to be infested. Borrelia infections were observed in 6.8% of the ticks tested. Two Borrelia species were identified by sequencing: B. hispanica and B. crocidurae. The discovery in northwestern Morocco of Ornithodoros ticks infected by B. crocidurae represents a 350 km range extension of this Sahelo-Saharan spirochete in North Africa. The spread of B. crocidurae may be related to the increasing aridity of northwestern Morocco in relation to climate change.
First detection of "Candidatus Rickettsia wissemanii" in Ornithodoros hasei (Schulze, 1935) (Acari: Argasidae) from Argentina.
Colombo Valeria C,Montani Maria E,Pavé Romina,Antoniazzi Leandro R,Gamboa Marcelo D,Fasano Agustín A,Félix Maria L,Nava Santiago,Venzal José M
Ticks and tick-borne diseases
The aim of this study was to assess the presence of Rickettsia in soft ticks (Acari: Argasidae) collected from insectivorous bats (Chiroptera) in Santa Fe province, Argentina. First, a subset of ticks were mounted in Hoyer's medium to be determined by morphological characters and then confirmed by sequencing the mitochondrial 16S rRNA gene. Also ticks were processed by PCR assays using primers CS-78 and CS-323, which amplify a fragment of the Rickettsia spp. gltA gene. Positive ticks were subjected to a second PCR round with primers Rr190.70p and Rr190.701n of the spotted fever group rickettsiae ompA gene. A phylogenetic analysis was performed with Maximum-likelihood method, and the best fitting substitution models were determined with the Akaike Information Criterion. Five bats of the species Eptesicus diminutus Osgood, 1915, Eptesicus furinalis (d'Orbigny and Gervais, 1847), Eptesicus spp. (Vespertilionidae), and Molossops temminckii Burmeister, 1854 (Molossidae) were parasitized with Ornithodoros hasei (Schulze, 1935) larvae. One E. diminutus ticks' tested positive to "Candidatus Rickettsia wissemanii", a spotted fever group rickettsiae. The association O. hasei -"Ca. R. wissemanii" detected in this study represents the first evidence of a Rickettsia in Ornithodoros ticks in Argentina and the third report of this association in America. Also, this finding constitutes the first record of "Ca. R. wissemanii" in Argentina. Finally, we found for the first time the insectivorous bats E. diminutus and E. furinalis parasitized with O. hasei larvae. These findings add two new hosts and a new location, the southernmost recorded to date, for O. hasei.
Acquisition and subsequent transmission of Borrelia hermsii by the soft tick Ornithodoros hermsi.
Lopez Job E,Mccoy Brandi N,Krajacich Benjamin J,Schwan Tom G
Journal of medical entomology
Tick-borne relapsing fever is caused by spirochetes within the genus Borrelia. The hallmark of this disease is recurrent febrile episodes and high spirochete densities in mammalian blood resulting from immune evasion. Between episodes of spirochetemia when bacterial densities are low, it is unknown whether ticks can acquire the spirochetes, become colonized by the bacteria, and subsequently transmit the bacteria once they feed again. We addressed these questions by feeding ticks, Omnithodoros hermsi Wheeler (Acari: Argasidae),daily on an infected mouse during low andhigh levels of spirochete infections. This study demonstrates that spirochete acquisition by the tick vector can occur during low levels of mammalian infection and that once a spirochetemic threshold is attained within the blood, nearly 100% of ticks become colonized by Borrelia hermsii.
Borrelia hispanica in Ornithodoros erraticus, Portugal.
Palma M,Lopes de Carvalho I,Figueiredo M,Amaro F,Boinas F,Cutler S J,Núncio M S
Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases
Tick-borne relapsing fever (TBRF) is a spirochetal infection caused by the genus Borrelia. The disease is distributed in the Old and New World with many different species reported. In Europe, TBRF is caused by B. hispanica transmitted to man by Ornithodoros erraticus, a soft tick usually found in old premises to shelter pig herds. In Portugal, the first human case of TBRF was reported in 1942 but since the beginning of the 1960s, the disease has rarely been described and seems to either have disappeared or have been undiagnosed. Therefore, in 2009 a survey was undertaken to evaluate the presence of the tick in this type of premises and to evaluate its role as a reservoir of Borrelia. The work was carried out where the ticks were previously reported in the Alentejo and Algarve regions. Of 63 pigpens surveyed, O. erraticus was collected from 19% (n = 12) of these pigpens using CO(2) traps. To evaluate potential Borrelia hosts, both pigs (n = 25) and small rodents (n = 10) inhabiting these pigpens were surveyed for Borrelia presence, by whole blood PCR and/or tissue culture, respectively. All results for pigs and rodents were negative for the presence of B. hispanica. PCR assays targeting the 16S rRNA gene and intergenic spacer region of Borrelia were used. Sequence analysis of the positive samples confirmed the presence of B. hispanica in 2.2% (n = 5) of ticks from a pigpen in Alentejo. These results confirm natural, but albeit low, persistence of this agent in Portugal.
Identification of Bartonellae in the soft tick species Ornithodoros sonrai in Senegal.
Mediannikov Oleg,Diatta Georges,Kasongo Kangaji,Raoult Didier
Vector borne and zoonotic diseases (Larchmont, N.Y.)
Ticks, belonging to the soft ticks species Ornithodorus sonrai, have been collected from six sites in Senegal and were tested for the presence of Bartonella spp. Initial screening by PCR revealed the presence of these bacteria in ticks from two villages, Soulkhou Thissé (5/8, 62.5%) and Maka Gouye (1/24, 4.2%). Three bacterial strains were isolated from live ticks, and the genetic characterization of these strains suggests that they belong to two previously unknown species. The pathogenicity of these two new species of Bartonella is not yet known. The new isolates described here are the first strains of Bartonella spp. from soft ticks and the first isolates from any arthropod species in Africa.
Coxiella symbiont in the tick Ornithodoros rostratus (Acari: Argasidae).
Almeida Aliny P,Marcili Arlei,Leite Romario C,Nieri-Bastos Fernanda A,Domingues Luísa N,Martins João Ricardo,Labruna Marcelo B
Ticks and tick-borne diseases
In the present study, the presence of tick-associated bacteria and protozoa in Ornithodoros rostratus ticks (adults, nymphs, and eggs) from the Pantanal region of Brazil were determined by molecular detection. In these ticks, DNA from protozoa in the genera Babesia and Hepatozoon, and bacteria from the genera Rickettsia, Borrelia, Anaplasma, and Ehrlichia were not detected. Conversely, all tested ticks (100%) yielded PCR products for 3 Coxiella genes (16S rRNA, pyrG, cap). PCR and phylogenetic analysis of 3 amplified genes (16S rRNA, pyrG, cap) demonstrated that the agent infecting O. rostratus ticks was a member of the genus Coxiella. This organism grouped with Coxiella symbionts of other soft tick species (Argasidae), having different isolates of C. burnetii as a sister group, and these 2 groups formed a clade that grouped with another clade containing Coxiella symbionts of hard tick species (Ixodidae). Analysis of tick mitochondrial 16S rRNA gene database composed mostly of tick species previously shown to harbor Coxiella symbionts suggests a phylogenetic congruence of ticks and their Coxiella symbionts. Furthermore, these results suggest a very long period of coevolution between ticks and Coxiella symbionts and indicates that the original infection may have occurred in an ancestor common to the 2 main tick families, Argasidae (soft ticks) and Ixodidae (hard ticks). However, this evolutionary relationship must be confirmed by more extensive testing of additional tick species and expanded populations.
Borrelia crocidurae infection of Ornithodoros erraticus (Lucas, 1849) ticks in Tunisia.
Bouattour Ali,Garnier Martine,M'Ghirbi Youmna,Sarih M'hammed,Gern Lise,Ferquel Elisabeth,Postic Danièle,Cornet Muriel
Vector borne and zoonotic diseases (Larchmont, N.Y.)
Tick-borne relapsing fever (TBRF) is caused by Borrelia species transmitted to humans by infected Ornithodoros sp. ticks. The disease has been rarely described in North Africa, and in Tunisia the local transmission of TBRF seems to have disappeared or is undiagnosed. A longitudinal study was conducted in 14 sites located in four different bioclimatic zones of Tunisia to assess both the distribution of Ornithodoros sp. and their infection rate with the relapsing fever Borrelia sp. Three polymerase chain reaction methods targeting the 16S rRNA, the intergenic spacer, and the fla (flagellin) genes were used and phylogenetic analyses were carried out. Three hundred and fifty-eight specimens of Ornithodoros were collected: O. erraticus (previously termed "small variety") (n = 190) and O. normandi (n = 168). Borrelia crocidurae DNA was detected in 15.1% of O. erraticus (small variety) (24 out of the 159 randomly selected for testing) collected in rodent burrows situated in the arid and Saharan areas in southern Tunisia. Molecular analysis targeting the 16S rRNA gene and the noncoding intergenic spacer domain showed good resolution for this Borrelia sp., although no molecular polymorphism was evidenced according to location. In contrast, none of the 133 O. normandi, also randomly selected for testing, was infected by Borrelia sp. and these ticks were restricted to the subhumid and semiarid zones in northern Tunisia. Both O. erraticus (small variety) and O. normandi were found in Tunisia and the high B. crocidurae infection rate found in O. erraticus highlights the risk of TBRF transmission in the southern part of the country.
New records and human parasitism by Ornithodoros mimon (Acari: Argasidae) in Brazil.
Labruna Marcelo B,Marcili Arlei,Ogrzewalska Maria,Barros-Battesti Darci M,Dantas-Torres Filipe,Fernandes André A,Leite Romario C,Venzal Jose M
Journal of medical entomology
The bat tick Ornithodoros mimon Kohls, Clifford & Jones is currently known by only few reports in Bolivia, Uruguay, Argentina, and the state of São Paulo in southeastern Brazil. Here, we expand the distribution of O. mimon in Brazil to the states of Minas Gerais (southeastern region), Goiás (central-western), Pernambuco, and Rio Grande do Norte (northeastern). Ticks were collected on human dwellings, where there had been repeated complains of tick bites on persons during the night. Tick bites were generally followed by intense inflammatory reactions that lasted for several weeks at the bite site. Bats and opossums were reported to inhabit the attic of the infested houses. In addition, a free-ranging opossum (Didelphis albiventris Lund) trapped in Rio Grande do Norte was found infested by argasid larvae. Based on morphological and/or molecular analysis, all ticks were identified as O. mimon. From one of the sites (Tiradentes, state of Minas Gerais), 20 field-collected nymphs were tested by a battery of polymerase chain reaction protocols targeting tick-borne microorganisms of the genera Babesia, Hepatozoon, Rickettsia, Borrelia, Anaplasma, Ehrlichia, and Coxiella; no tick specimen was found infected by any of these microorganism genera. The current study expands northwards the distribution of O. mimon, which has been shown to be very harmful to humans because of the intense inflammatory response that usually occurs after tick bites.
Rickettsia lusitaniae sp. nov. isolated from the soft tick Ornithodoros erraticus (Acarina: Argasidae).
Milhano Natacha,Palma Mariana,Marcili Arlei,Núncio Maria Sofia,de Carvalho Isabel Lopes,de Sousa Rita
Comparative immunology, microbiology and infectious diseases
In this study a novel Rickettsia from the spotted fever group, isolated from Ornithodoros erraticus soft ticks collected from pigpens in the south of Portugal, is described. After initial screening revealed Rickettsia-positive ticks, isolation attempts were then performed. Successful isolates were achieved by shell-vial technique using Vero E6 cells at 28°C. Molecular characterization of the isolate was performed based on analysis of five rickettsial genes gltA, ompA, ompB, sca1 and htr with their subsequent concatenation along with other rickettsial species resulting in a clustering of the new isolate with Rickettsia felis and Rickettsia hoogstraalii. The degree of nucleotide sequence similarity with other rickettsiae fulfills the criteria for classification of our isolate as a novel species. The name Rickettsia lusitaniae sp. nov. (=CEVDI PoTiRo) is proposed for this new species found in O. erraticus.
Ubiquitous bacteria Borrelia crocidurae in Western African ticks Ornithodoros sonrai.
Elbir Haitham,FotsoFotso Aurélien,Diatta Georges,Trape Jean François,Arnathau Céline,Renaud François,Durand Patrick
Parasites & vectors
BACKGROUND:In West Africa, tick-borne relapsing fever is a neglected arthropod-borne infection caused by Borrelia crocidurae transmitted by the argasid tick Ornithodoros sonrai. From an epidemiological point of view, it is of interest to know whether some genotypes of the vector are specialized in carrying certain genotypes of the pathogen. FINDINGS:Thirty-five O. sonrai ticks collected in Mali, Senegal, Mauritania and Morocco confirmed to be B. crocidurae-infected, were genotyped by 16S rRNA gene sequencing. B. crocidurae was genotyped by Multispacer Sequence Typing. The 35 O. sonrai ticks grouped into 12 genotypes with strong geographical structuration. MST resolved the 35 B. crocidurae isolates into 29 genotypes with pairwise divergence of 0.09 - 1.56 % without strict geographical structuration as genotype ST22 was found in Mali, Senegal and Mauritania. There was no evidence of tick-borrelia specialization as one O. sonrai genotype carried several B. crocidurae genotypes and one B. crocidurae genotype was found in different O. sonrai genotypes. CONCLUSIONS:This report illustrates a non-specialized circulation of B. crocidurae borreliae within O. sonrai ticks in West Africa.
Ecological niche modeling and distribution of Ornithodoros hermsi associated with tick-borne relapsing fever in western North America.
Sage Kylie M,Johnson Tammi L,Teglas Michael B,Nieto Nathan C,Schwan Tom G
PLoS neglected tropical diseases
Tick-borne relapsing fever in western North America is a zoonosis caused by the spirochete bacterium, Borrelia hermsii, which is transmitted by the bite of infected Ornithodoros hermsi ticks. The pathogen is maintained in natural cycles involving small rodent hosts such as chipmunks and tree squirrels, as well as the tick vector. In order for these ticks to establish sustained and viable populations, a narrow set of environmental parameters must exist, primarily moderate temperatures and moderate to high amounts of precipitation. Maximum Entropy Species Distribution Modeling (Maxent) was used to predict the species distribution of O. hermsi and B. hermsii through time and space based on current climatic trends and future projected climate changes. From this modeling process, we found that the projected current distributions of both the tick and spirochete align with known endemic foci for the disease. Further, global climate models predict a shift in the distribution of suitable habitat for the tick vector to higher elevations. Our predictions are useful for targeting surveillance efforts in areas of high risk in western North America, increasing the efficiency and accuracy of public health investigations and vector control efforts.
Rickettsia lusitaniae associated with Ornithodoros yumatensis (Acari: Argasidae) from two caves in Yucatan, Mexico.
Sánchez-Montes Sokani,Guzmán-Cornejo Carmen,Martínez-Nájera Yecenia,Becker Ingeborg,Venzal José M,Labruna Marcelo B
Ticks and tick-borne diseases
The genus Rickettsia includes obligate intracellular bacteria transmitted by several hematophagous arthropods such as ticks, fleas and sucking lice. In particular hard ticks (Ixodidae) have been cited as the main vectors of pathogenic rickettsiae in Mexico. However, there have been only two records of a single Rickettsia species associated with Mexican soft ticks (Argasidae). In this study, we searched for rickettsial DNA in argasid ticks (13 adults and eight nymphs of Ornithodoros yumatensis) from two bat caves in the state of Yucatan, Mexico. Additionally one larva collected in a cave from Chiapas, Mexico, and associated with Desmodus rotundus was used to corroborate the tick taxonomic determination. Of these, nine ticks (43%) yielded expected PCR products for the rickettsial gltA gene. These PCR-positive ticks were tested with additional PCR protocols targeting the rickettsial genes gltA, ompA and ompB. DNA partial sequences from these genes showed 99-100% identities with Rickettsia lusitaniae, an agent isolated from O. erraticus in Portugal, and closely related to R. felis and R. hoogstraalii. Based on the results from this study, the inventory of rickettsiae distributed in Mexico increases from six to seven species.
Clinical Findings Associated with Ornithodoros brasiliensis Tick Parasitism in Travelers, Southern Brazil.
Dall'Agnol Bruno,Schott Diogo,Padilha Thamiris,Antunes Paola,Souza Ugo A,Webster Anelise,Souza Getúlio D,Ferreira Carlos Alexandre S,Reck José
Wilderness & environmental medicine
We report a series of clinical cases associated with parasitism by the Ornithodoros brasiliensis tick in a group of travelers in the Caxias do Sul municipality, Southern Brazil. These cases draw attention to underdiagnosed noninfectious syndromes caused by ticks with restricted local distributions.
Novel Babesia and Hepatozoon agents infecting non-volant small mammals in the Brazilian Pantanal, with the first record of the tick Ornithodoros guaporensis in Brazil.
Wolf Rafael William,Aragona Mônica,Muñoz-Leal Sebastián,Pinto Leticia Borges,Melo Andréia Lima Tomé,Braga Isis Assis,Costa Jackeliny dos Santos,Martins Thiago Fernandes,Marcili Arlei,Pacheco Richard de Campos,Labruna Marcelo B,Aguiar Daniel Moura
Ticks and tick-borne diseases
Taking into account the diversity of small terrestrial mammals of the Pantanal, the present study aimed to verify the occurrence of infection by Ehrlichia spp., Anaplasma spp., Rickettsia spp., Hepatozoon spp., Babesia spp. and parasitism by ticks in non-volant small mammals collected in the Brazilian Pantanal. Samples of blood, liver and spleen were collected from 64 captured animals, 22 marsupials and 42 rodents. Pathogen detection was performed by the use of genus-specific Polymerase Chain Reaction (PCR) assays. Ticks collected from the animals consisted of Amblyomma sculptum and Amblyomma triste nymphs, and Ornithodoros guaporensis larvae. None of the vertebrate samples (blood, liver, or spleen) yielded detectable DNA of Rickettsia spp. or Ehrlichia spp. The blood of the rodent Hylaeamys megacephalus yielded an Anaplasma sp. genotype (partial 16S rRNA gene) 99% similar to multiple Anaplasma spp. genotypes around the world. The blood of three rodents of the species Calomys callosus were positive for a novel Hepatozoon sp. agent, phylogenetically related (18S rDNA gene) to distinct Hepatozoon genotypes that have been detected in rodents from different parts of the world. One marsupial (Monodelphis domestica) and three rodents (Thrichomys pachyurus) were positive to novel piroplasmid genotypes, phylogenetically (18S rDNA gene) related to Theileria bicornis, Cytauxzoon manul, and Cytauxzoon felis. The present study provides the first molecular detection of Hepatozoon sp. and piroplasmids in small mammals in Brazil. Additionally, we expanded the distribution of O. guaporensis to Brazil, since this tick species was previously known to occur only in Bolivia.
Coxiella-like endosymbiont in argasid ticks (Ornithodoros muesebecki) from a Socotra Cormorant colony in Umm Al Quwain, United Arab Emirates.
Al-Deeb Mohammad A,Frangoulidis Dimitrios,Walter Mathias C,Kömpf Daniela,Fischer Silke F,Petney Trevor,Muzaffar Sabir Bin
Ticks and tick-borne diseases
Coxiella burnetii is a pathogen causing Q fever in domestic animals and humans. Seabirds have been implicated as possible reservoirs of this bacterium in the Arabian Gulf and in the Western Indian Ocean. Recently, Coxiella species closely related to C. burnetii was detected from ticks collected from oil rigs used as roosting areas by Socotra Cormorants (Phalacrocorax nigrogularis) in the western Arabian Gulf. We collected ticks from the largest breeding colony of Socotra Cormorants in the United Arab Emirates on the eastern extreme of the species' breeding range to determine the prevalence of C. burnetii and evaluate its role as a wild reservoir. All ticks were identified as Ornithodoros muesebecki and genomic DNA was extracted from larval and nymph/adult tick pools. Multiplex PCR tests were performed targeting three C. burnetii specific genes. C. burnetii was not detected although a Coxiella-like endosymbiont was identified that was closely related to Coxiella symbionts from Ornithodoros capensis ticks. Because domestic and wild ungulates are the primary source of C. burnetii, we suggest that the presence of free-ranging, native and non-native ungulates in some off-shore islands in the Arabian Gulf could disseminate C. burnetii to seabirds. More comprehensive studies on seabird colonies are needed to better understand the diversity and prevalence of Coxiella symbionts and to establish if C. burnetii is endemic on some of these islands.
New Rickettsia species in soft ticks Ornithodoros hasei collected from bats in French Guiana.
Tahir Djamel,Socolovschi Cristina,Marié Jean-Lou,Ganay Gautier,Berenger Jean-Michel,Bompar Jean-Michel,Blanchet Denis,Cheuret Marie,Mediannikov Oleg,Raoult Didier,Davoust Bernard,Parola Philippe
Ticks and tick-borne diseases
In French Guiana, located on the northeastern coast of South America, bats of different species are very numerous. The infection of bats and their ticks with zoonotic bacteria, especially Rickettsia species, is so far unknown. In order to improve knowledge of these zoonotic pathogens in this French overseas department, the presence and diversity of tick-borne bacteria was investigated with molecular tools in bat ticks. In the beginning of 2013, 32 bats were caught in Saint-Jean-du-Maroni, an area close to the coast of French Guiana, and the ticks of these animals were collected. A total of 354 larvae of Argasidae soft ticks (Ornithodoros hasei) from 12 bats (Noctilio albiventris) were collected and 107 of them were analysed. DNA was extracted from the samples and quantitative real-time PCR was carried out to detect Rickettsia spp., Bartonella spp., Borrelia spp. and Coxiella burnetii. All tested samples were negative for Bartonella spp., Borrelia spp. and Coxiella burnetii. Rickettsia DNA was detected in 31 (28.9%) ticks. An almost entire (1118 base pairs long) sequence of the gltA gene was obtained after the amplification of some positive samples on conventional PCR and sequencing. A Bayesian tree was constructed using concatenated rrs, gltA, ompA, ompB, and gene D sequences. The study of characteristic sequences shows that this Rickettsia species is very close (98.3-99.8%) genetically to R. peacockii. Nevertheless, the comparative analysis of sequences obtained from gltA, ompA, ompB, rrs and gene D fragments demonstrated that this Rickettsia is different from the other members of the spotted fever group. The sequences of this new species were deposited in GenBank as Candidatus Rickettsia wissemanii. This is the first report showing the presence of nucleic acid of Rickettsia in Ornithodoros hasei ticks from South American bats.
'Candidatus Rickettsia nicoyana': A novel Rickettsia species isolated from Ornithodoros knoxjonesi in Costa Rica.
Moreira-Soto Rolando D,Moreira-Soto Andrés,Corrales-Aguilar Eugenia,Calderón-Arguedas Ólger,Troyo Adriana
Ticks and tick-borne diseases
Rickettsiae are intracellular bacteria commonly associated with hematophagous arthropods. Most of them have been described in hard ticks, but some have been found in soft ticks. Here we report the detection and isolation of a new Rickettsia from Ornithodoros knoxjonesi larvae collected from Balantiopteryx plicata (Emballonuridae) in Nicoya, Costa Rica. Two ticks were processed to detect Rickettsia spp. genes gltA, ompA, ompB, and htrA by PCR. Part of the macerate was also inoculated into Vero E6 and C6/36 cell lines, and cells were evaluated by Giménez stain, indirect immunofluorescence assay (IFA), and PCR. Both ticks were positive by PCR and rickettsial growth was successful in Vero E6 cells. Amplification and sequencing of near full length rrs, gltA, sca4 genes, and fragments of ompA and ompB showed that the Rickettsia sp. was different from described species. The highest homologies were with 'Candidatus Rickettsia wissemanii' and Rickettsia peacockii: 99.70% (1321/1325) with both sequences for rrs, 99.58% (1172/1177) and 99.76% (1246/1249) for gltA, 99.26% with both sequences (2948/2970 and 2957/2979) for sca4, 98.78% (485/491) and 98.39% (2069/2115) for ompA, and 98.58 (1453/1474) and 98.92% (1459/1475) for ompB; respectively. Bat blood, spleen, liver, and lung samples analyzed for Rickettsia detection were negative. Results demonstrate that the Rickettsia isolated from O. knoxjonesi is probably an undescribed species that belongs to the spotted fever group, for which 'Candidatus Rickettsia nicoyana' is proposed. Considering that B. plicata inhabits areas where contact with humans may occur and that human parasitism by Ornithodoros has been reported in the country, it will be important to continue with the characterization of this species and its pathogenic potential.
The epidemiology and geographic distribution of relapsing fever borreliosis in West and North Africa, with a review of the Ornithodoros erraticus complex (Acari: Ixodida).
Trape Jean-François,Diatta Georges,Arnathau Céline,Bitam Idir,Sarih M'hammed,Belghyti Driss,Bouattour Ali,Elguero Eric,Vial Laurence,Mané Youssouph,Baldé Cellou,Prugnolle Franck,Pugnolle Franck,Chauvancy Gilles,Mahé Gil,Granjon Laurent,Duplantier Jean-Marc,Durand Patrick,Renaud François
BACKGROUND:Relapsing fever is the most frequent bacterial disease in Africa. Four main vector / pathogen complexes are classically recognized, with the louse Pediculus humanus acting as vector for B. recurrentis and the soft ticks Ornithodoros sonrai, O. erraticus and O. moubata acting as vectors for Borrelia crocidurae, B. hispanica and B. duttonii, respectively. Our aim was to investigate the epidemiology of the disease in West, North and Central Africa. METHODS AND FINDINGS:From 2002 to 2012, we conducted field surveys in 17 African countries and in Spain. We investigated the occurrence of Ornithodoros ticks in rodent burrows in 282 study sites. We collected 1,629 small mammals that may act as reservoir for Borrelia infections. Using molecular methods we studied genetic diversity among Ornithodoros ticks and Borrelia infections in ticks and small mammals. Of 9,870 burrows investigated, 1,196 (12.1%) were inhabited by Ornithodoros ticks. In West Africa, the southern and eastern limits of the vectors and Borrelia infections in ticks and small mammals were 13°N and 01°E, respectively. Molecular studies revealed the occurrence of nine different Ornithodoros species, including five species new for science, with six of them harboring Borrelia infections. Only B. crocidurae was found in West Africa and three Borrelia species were identified in North Africa: B. crocidurae, B. hispanica, and B. merionesi. CONCLUSIONS:Borrelia Spirochetes responsible for relapsing fever in humans are highly prevalent both in Ornithodoros ticks and small mammals in North and West Africa but Ornithodoros ticks seem absent south of 13°N and small mammals are not infected in these regions. The number of Ornithodoros species acting as vector of relapsing fever is much higher than previously known.
Comparative vector competence of the Afrotropical soft tick Ornithodoros moubata and Palearctic species, O. erraticus and O. verrucosus, for African swine fever virus strains circulating in Eurasia.
Pereira de Oliveira Rémi,Hutet Evelyne,Paboeuf Frédéric,Duhayon Maxime,Boinas Fernando,Perez de Leon Adalberto,Filatov Serhii,Vial Laurence,Le Potier Marie-Frédérique
African swine fever (ASF) is a lethal hemorrhagic disease in domestic pigs and wild suids caused by African swine fever virus (ASFV), which threatens the swine industry globally. In its native African enzootic foci, ASFV is naturally circulating between soft ticks of the genus Ornithodoros, especially in the O. moubata group, and wild reservoir suids, such as warthogs (Phacochoerus spp.) that are bitten by infected soft ticks inhabiting their burrows. While the ability of some Afrotropical soft ticks to transmit and maintain ASFV is well established, the vector status of Palearctic soft tick species for ASFV strains currently circulating in Eurasia remains largely unknown. For example, the Iberian soft tick O. erraticus is a known vector and reservoir of ASFV, but its ability to transmit different ASFV strains has not been assessed since ASF re-emerged in Europe in 2007. Little is known about vector competence for ASFV in other species, such as O. verrucosus, which occurs in southern parts of Eastern Europe, including Ukraine and parts of Russia, and in the Caucasus. Therefore, we conducted transmission trials with two Palearctic soft tick species, O. erraticus and O. verrucosus, and the Afrotropical species O. moubata. We tested the ability of ticks to transmit virulent ASFV strains, including one of direct African origin (Liv13/33), and three from Eurasia that had been involved in previous (OurT88/1), and the current epizooties (Georgia2007/1 and Ukr12/Zapo). Our experimental results showed that O. moubata was able to transmit the African and Eurasian ASFV strains, whereas O. erraticus and O. verrucosus failed to transmit the Eurasian ASFV strains. However, naïve pigs showed clinical signs of ASF when inoculated with homogenates of crushed O. erraticus and O. verrucosus ticks that fed on viraemic pigs, which proved the infectiousness of ASFV contained in the ticks. These results documented that O. erraticus and O. verrucosus are unlikely to be capable vectors of ASFV strains currently circulating in Eurasia. Additionally, the persistence of infection in soft ticks for several months reaffirms that the infectious status of a given tick species is only part of the data required to assess its vector competence for ASFV.