Genetic control of bacterial biofilms.
Wolska Krystyna I,Grudniak Anna M,Rudnicka Zofia,Markowska Katarzyna
Journal of applied genetics
Nearly all bacterial species, including pathogens, have the ability to form biofilms. Biofilms are defined as structured ecosystems in which microbes are attached to surfaces and embedded in a matrix composed of polysaccharides, eDNA, and proteins, and their development is a multistep process. Bacterial biofilms constitute a large medical problem due to their extremely high resistance to various types of therapeutics, including conventional antibiotics. Several environmental and genetic signals control every step of biofilm development and dispersal. From among the latter, quorum sensing, cyclic diguanosine-5'-monophosphate, and small RNAs are considered as the main regulators. The present review describes the control role of these three regulators in the life cycles of biofilms built by Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella enterica serovar Typhimurium, and Vibrio cholerae. The interconnections between their activities are shown. Compounds and strategies which target the activity of these regulators, mainly quorum sensing inhibitors, and their potential role in therapy are also assessed.
10.1007/s13353-015-0309-2
[The loop mediated isothermal amplification of DNA: principle of method and perspectives of application in molecular diagnostic of cholera: publications review].
Mironova L V,Adelshin R V,Biketov S F,Shchit I A,Dyatlov I A,Balakhonov S V
Klinicheskaia laboratornaia diagnostika
The article considers characteristics of technology of reaction of loop mediated isothermal amplification of DNA (LAMP), issues of optimization of reaction and perspectives of its application as a quick highly-specific test in molecular diagnostics of infectious diseases and monitoring of contamination of environment objects with pathogens. The analysis of publications data concerning application of LAMP in diagnostics of cholera testifies high diagnostic value. The LAMP supports possibility of direct rapid detection of toxin-producing strains of Vibrio cholerae in clinical samples. This technique also provides identification of determinants of cholera vibrio in pure culture, samples from environment objects and food products. The research studies established exceeding of parameters of sensitivity and specificity of LAMP as compared with polymerase chain reaction that permits considering LAMP as a perspective technique for express-analysis of clinical material from patients with suspicion on cholera. The LAMP technique can be also used in screening studies of environment objects. The development of test-systems based on application of this technology is required.
Biofilm Matrix Proteins.
Fong Jiunn N C,Yildiz Fitnat H
Microbiology spectrum
Proteinaceous components of the biofilm matrix include secreted extracellular proteins, cell surface adhesins, and protein subunits of cell appendages such as flagella and pili. Biofilm matrix proteins play diverse roles in biofilm formation and dissolution. They are involved in attaching cells to surfaces, stabilizing the biofilm matrix via interactions with exopolysaccharide and nucleic acid components, developing three-dimensional biofilm architectures, and dissolving biofilm matrix via enzymatic degradation of polysaccharides, proteins, and nucleic acids. In this article, we will review functions of matrix proteins in a selected set of microorganisms, studies of the matrix proteomes of Vibrio cholerae and Pseudomonas aeruginosa, and roles of outer membrane vesicles and of nucleoid-binding proteins in biofilm formation.
10.1128/microbiolspec.MB-0004-2014
Living in the matrix: assembly and control of Vibrio cholerae biofilms.
Nature reviews. Microbiology
Nearly all bacteria form biofilms as a strategy for survival and persistence. Biofilms are associated with biotic and abiotic surfaces and are composed of aggregates of cells that are encased by a self-produced or acquired extracellular matrix. Vibrio cholerae has been studied as a model organism for understanding biofilm formation in environmental pathogens, as it spends much of its life cycle outside of the human host in the aquatic environment. Given the important role of biofilm formation in the V. cholerae life cycle, the molecular mechanisms underlying this process and the signals that trigger biofilm assembly or dispersal have been areas of intense investigation over the past 20 years. In this Review, we discuss V. cholerae surface attachment, various matrix components and the regulatory networks controlling biofilm formation.
10.1038/nrmicro3433
Vibrio cholerae Biofilms and Cholera Pathogenesis.
Silva Anisia J,Benitez Jorge A
PLoS neglected tropical diseases
Vibrio cholerae can switch between motile and biofilm lifestyles. The last decades have been marked by a remarkable increase in our knowledge of the structure, regulation, and function of biofilms formed under laboratory conditions. Evidence has grown suggesting that V. cholerae can form biofilm-like aggregates during infection that could play a critical role in pathogenesis and disease transmission. However, the structure and regulation of biofilms formed during infection, as well as their role in intestinal colonization and virulence, remains poorly understood. Here, we review (i) the evidence for biofilm formation during infection, (ii) the coordinate regulation of biofilm and virulence gene expression, and (iii) the host signals that favor V. cholerae transitions between alternative lifestyles during intestinal colonization, and (iv) we discuss a model for the role of V. cholerae biofilms in pathogenicity.
10.1371/journal.pntd.0004330
Host-Microbe-Pathogen Interactions: A Review of Pathogenesis in .
Frontiers in immunology
Most animals maintain mutually beneficial symbiotic relationships with their intestinal microbiota. Resident microbes in the gastrointestinal tract breakdown indigestible food, provide essential nutrients, and, act as a barrier against invading microbes, such as the enteric pathogen . Over the last decades, our knowledge of pathogenesis, colonization, and transmission has increased tremendously. A number of animal models have been used to study how interacts with host-derived resources to support gastrointestinal colonization. Here, we review studies on host-microbe interactions and how infection with disrupts these interactions, with a focus on contributions from the model. We will discuss studies that highlight the connections between symbiont, host, and metabolism; crosstalk between and host microbes; and the impact of the host immune system on the lethality of infection. These studies suggest that modulates host immune-metabolic responses in the fly and improves fitness through competition with intestinal microbes.
10.3389/fimmu.2019.03128
Intestinal Colonization Dynamics of Vibrio cholerae.
Almagro-Moreno Salvador,Pruss Kali,Taylor Ronald K
PLoS pathogens
To cause the diarrheal disease cholera, Vibrio cholerae must effectively colonize the small intestine. In order to do so, the bacterium needs to successfully travel through the stomach and withstand the presence of agents such as bile and antimicrobial peptides in the intestinal lumen and mucus. The bacterial cells penetrate the viscous mucus layer covering the epithelium and attach and proliferate on its surface. In this review, we discuss recent developments and known aspects of the early stages of V. cholerae intestinal colonization and highlight areas that remain to be fully understood. We propose mechanisms and postulate a model that covers some of the steps that are required in order for the bacterium to efficiently colonize the human host. A deeper understanding of the colonization dynamics of V. cholerae and other intestinal pathogens will provide us with a variety of novel targets and strategies to avoid the diseases caused by these organisms.
10.1371/journal.ppat.1004787
[Biofilm development and environmental determinants in Vibrio cholerae].
Wang Quanmin,Ma Yao,Liu Lijun,Zhu Jun,Liu Zhi
Sheng wu gong cheng xue bao = Chinese journal of biotechnology
Biofilm associated Vibrio cholerae exhibits hypervirulence and supreme fitness against the harsh stresses during its infectious cycle. It is important to study the relationships between the regulation mechanism of V. cholerae biofilm development and its environmental adaption in host niche and aquatic habitat. Here, we summarize the recent advances in V. cholerae biofilm, including biofilm compositions, development and regulation. Particularly, we extensively discuss how V. cholerae fosters its biofilm architecture and assembly via sensing and responding various environmental determinants, such as bacterium self-produced molecules, natural environment components and host factors.
10.13345/j.cjb.170052
T6SS intraspecific competition orchestrates Vibrio cholerae genotypic diversity.
Kostiuk Benjamin,Unterweger Daniel,Provenzano Daniele,Pukatzki Stefan
International microbiology : the official journal of the Spanish Society for Microbiology
Vibrio cholerae is a diverse species that inhabits a wide range of environments from copepods in brackish water to the intestines of humans. In order to remain competitive, V. cholerae uses the versatile type-VI secretion system (T6SS) to secrete anti-prokaryotic and anti-eukaryotic effectors. In addition to competing with other bacterial species, V. cholerae strains also compete with one another. Some strains are able to coexist, and are referred to as belonging to the same compatibility group. Challenged by diverse competitors in various environments, different V. choleare strains secrete different combination of effectors - presumably to best suit their niche. Interestingly, all pandemic V. cholerae strains encode the same three effectors. In addition to the diversity displayed in the encoded effectors, the regulation of V. cholerae also differs between strains. Two main layers of regulation appear to exist. One strategy connects T6SS activity with behavior that is suited to fighting eukaryotic cells, while the other is linked with natural competence - the ability of the bacterium to acquire and incorporate extracellular DNA. This relationship between bacterial killing and natural competence is potentially a source of diversification for V. cholerae as it has been shown to incorporate the DNA of cells recently killed through T6SS activity. It is through this process that we hypothesize the transfer of virulence factors, including T6SS effector modules, to happen. Switching of T6SS effectors has the potential to change the range of competitors V. cholerae can kill and to newly define which strains V. cholerae can co-exist with, two important parameters for survival in diverse environments.
10.2436/20.1501.01.294
Diagnostic techniques for rapid detection of Vibrio cholerae O1/O139.
Ramamurthy Thandavarayan,Das Bhabatosh,Chakraborty Subhra,Mukhopadhyay Asish K,Sack David A
Vaccine
Cholera caused by the toxigenic Vibrio cholerae is still a major public health problem in many countries. This disease is mainly due to poor sanitation, hygiene and consumption of unsafe water. Several recent epidemics of cholera showed its increasing intensity, duration and severity of the illness. This indicates an urgent need for effective management and preventive measures in controlling the outbreaks and epidemics. In preventing and spread of epidemic cholera, rapid diagnostic tests (RDTs) are useful in screening suspected stool specimens, water/food samples. Several RDTs developed recently are considered as investigative tools in confirming cholera cases, as the culture techniques are difficult to establish and/or maintain. The usefulness of RDTs will be more at the point-of-care facilities as it helps to make appropriate decisions in the management of outbreaks or epidemiological surveillance by the public health authorities. Apart from RDTs, several other tests are available for the direct detection of either V. cholerae or its cholera toxin. Viable but non-culturable (VBNC) state of V. cholerae poses a great challenge in developing RDTs. The aim of this article is to provide an overview of current knowledge about RDT and other techniques with reference to their status and future potentials in detecting cholera/V. cholerae.
10.1016/j.vaccine.2019.07.099