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Cold Spring Harbor Perspectives in... Jun 2015The global significance of Campylobacter jejuni and Campylobacter coli as gastrointestinal human pathogens has motivated numerous studies to characterize their... (Review)
Review
The global significance of Campylobacter jejuni and Campylobacter coli as gastrointestinal human pathogens has motivated numerous studies to characterize their population biology and evolution. These bacteria are a common component of the intestinal microbiota of numerous bird and mammal species and cause disease in humans, typically via consumption of contaminated meat products, especially poultry meat. Sequence-based molecular typing methods, such as multilocus sequence typing (MLST) and whole genome sequencing (WGS), have been instructive for understanding the epidemiology and evolution of these bacteria and how phenotypic variation relates to the high degree of genetic structuring in C. coli and C. jejuni populations. Here, we describe aspects of the relatively short history of coevolution between humans and pathogenic Campylobacter, by reviewing research investigating how mutation and lateral or horizontal gene transfer (LGT or HGT, respectively) interact to create the observed population structure. These genetic changes occur in a complex fitness landscape with divergent ecologies, including multiple host species, which can lead to rapid adaptation, for example, through frame-shift mutations that alter gene expression or the acquisition of novel genetic elements by HGT. Recombination is a particularly strong evolutionary force in Campylobacter, leading to the emergence of new lineages and even large-scale genome-wide interspecies introgression between C. jejuni and C. coli. The increasing availability of large genome datasets is enhancing understanding of Campylobacter evolution through the application of methods, such as genome-wide association studies, but MLST-derived clonal complex designations remain a useful method for describing population structure.
Topics: Adaptation, Physiological; Campylobacter coli; Campylobacter jejuni; Evolution, Molecular; Recombination, Genetic
PubMed: 26101080
DOI: 10.1101/cshperspect.a018119 -
Gut Microbes Jul 2017Chemotaxis, a process that mediates directional motility toward or away from chemical stimuli (chemoeffectors/ligands that can be attractants or repellents) in the... (Review)
Review
Chemotaxis, a process that mediates directional motility toward or away from chemical stimuli (chemoeffectors/ligands that can be attractants or repellents) in the environment, plays an important role in the adaptation of Campylobacter jejuni to disparate niches. The chemotaxis system consists of core signal transduction proteins and methyl-accepting-domain-containing Transducer like proteins (Tlps). Ligands binding to Tlps relay a signal to chemotaxis proteins in the cytoplasm which initiate a signal transduction cascade, culminating into a directional flagellar movement. Tlps facilitate substrate-specific chemotaxis in C. jejuni, which plays an important role in the pathogen's adaptation, pathobiology and colonization of the chicken gastrointestinal tract. However, the role of Tlps in C. jejuni's host tissue specific colonization, physiology and virulence remains not completely understood. Based on recent studies, it can be predicted that Tlps might be important targets for developing strategies to control C. jejuni via vaccines and antimicrobials.
Topics: Animals; Bacterial Proteins; Campylobacter Infections; Campylobacter jejuni; Chemotaxis; Chickens; Gastrointestinal Tract
PubMed: 28080213
DOI: 10.1080/19490976.2017.1279380 -
Microbiology (Reading, England) Sep 2020is a major bacterial foodborne-pathogen. Ciprofloxacin is an important antibiotic for the treatment of , albeit high rates of fluoroquinolone resistance have limited...
is a major bacterial foodborne-pathogen. Ciprofloxacin is an important antibiotic for the treatment of , albeit high rates of fluoroquinolone resistance have limited its usefulness. Persister-cells are transiently antibiotic-tolerant fractions of bacterial populations and their occurrence has been associated with recalcitrant and persistent bacterial infections. Here, time-kill assays with ciprofloxacin (200×MIC, 25 µg ml) were performed in strains 81-176 and RM1221 and persister-cells were found. The frequency of survivors after 8 h of ciprofloxacin exposure was approx. 10 for both strains, while after 22 h the frequency was between 10-10, depending on the strain and growth-phase. Interestingly, the stationary-phase cultures did not display more persister-cells compared to exponential-phase cultures, in contrast to what has been observed in other bacterial species. Persister-cells after ampicillin exposure (100×MIC, 200 µg ml) were not detected, implying that persister-cell formation in is antibiotic-specific. In attempts to identify the mechanism of ciprofloxacin persister-cell formation, stringent or SOS responses were not found to play major roles. Overall, this study reports ciprofloxacin persister-cells in and challenges the notion of persister-cells as plainly dormant non-growing cells.
Topics: Ampicillin; Anti-Bacterial Agents; Bacterial Load; Campylobacter jejuni; Ciprofloxacin; DNA Damage; Drug Resistance, Bacterial; Drug Tolerance; Microbial Sensitivity Tests; SOS Response, Genetics
PubMed: 32697188
DOI: 10.1099/mic.0.000953 -
Virulence Apr 2013Campylobacter jejuni is a major cause of food-borne gastroenteritis worldwide. While mortality is low, morbidity imparted by post-infectious sequelae such as... (Review)
Review
Campylobacter jejuni is a major cause of food-borne gastroenteritis worldwide. While mortality is low, morbidity imparted by post-infectious sequelae such as Guillain-Barré syndrome, Reiter syndrome/reactive arthritis and irritable bowel syndrome is significant. In addition, the economic cost is high due to lost productivity. Food animals, particularly poultry, are the main reservoirs of C. jejuni. The over-use of antibiotics in the human population and in animal husbandry has led to an increase in antibiotic-resistant infections, particularly with fluoroquinolones. This is problematic because C. jejuni gastroenteritis is clinically indistinguishable from that caused by other bacterial pathogens, and such illnesses are usually treated empirically with fluoroquinolones. Since C. jejuni is naturally transformable, acquisition of additional genes imparting antibiotic resistance is likely. Therefore, an understanding of the antibiotic resistance mechanisms in C. jejuni is needed to provide proper therapy both to the veterinary and human populations.
Topics: Animals; Anti-Bacterial Agents; Campylobacter Infections; Campylobacter jejuni; Drug Resistance, Bacterial; Humans
PubMed: 23406779
DOI: 10.4161/viru.23753 -
FEMS Microbiology Reviews Apr 2005Microbial cell surface glycans in the form of glycolipids and glycoproteins frequently play important roles in cell-cell interaction and host immune responses. Given the... (Review)
Review
Microbial cell surface glycans in the form of glycolipids and glycoproteins frequently play important roles in cell-cell interaction and host immune responses. Given the likely importance of these surface structures in the survival and pathogenesis of Campylobacter jejuni, a concerted effort has been made to characterise these determinants genetically and structurally since the genome was sequenced in 2000. We review the considerable progress made in characterising the Campylobacter glycome including the lipooligosaccharide (LOS), the capsule and O- and N-linked protein glycosylation systems, and speculate on the roles played by glycan surface structures in the life-cycle of C. jejuni.
Topics: Animals; Bacterial Capsules; Bacterial Proteins; Campylobacter jejuni; Carbohydrate Sequence; Glycosylation; Humans; Lipopolysaccharides; Molecular Sequence Data
PubMed: 15808749
DOI: 10.1016/j.femsre.2005.01.003 -
Veterinary Microbiology Dec 2023Microaerophilic, Gram-negative Campylobacter jejuni is the causative agent of campylobacteriosis, the most common bacterial gastrointestinal infection worldwide.... (Review)
Review
Microaerophilic, Gram-negative Campylobacter jejuni is the causative agent of campylobacteriosis, the most common bacterial gastrointestinal infection worldwide. Adhesion is the crucial first step in both infection or interaction with the host and biofilm formation, and is a critical factor for bacterial persistence. Here we describe the proteins and other surface structures that promote adhesion to various surfaces, including abiotic surfaces, microorganisms, and animal and human hosts. In addition, we provide insight into the distribution of adhesion proteins among strains from different ecological niches and highlight unexplored proteins involved in C. jejuni adhesion. Protein-protein, protein-glycan, and glycan-glycan interactions are involved in C. jejuni adhesion, with different factors contributing to adhesion to varying degrees under different circumstances. As adhesion is essential for survival and persistence, it represents an interesting target for C. jejuni control. Knowledge of the adhesion process is incomplete, as different molecular and functional aspects have been studied for different structures involved in adhesion. Therefore, it is important to strive for an integration of different approaches to obtain a clearer picture of the adhesion process on different surfaces and to consider the involvement of proteins, glycoconjugates, and polysaccharides and their cooperation.
Topics: Humans; Animals; Bacterial Adhesion; Campylobacter jejuni; Molecular Structure; Polysaccharides; Campylobacter Infections
PubMed: 38029692
DOI: 10.1016/j.vetmic.2023.109918 -
Frontiers in Cellular and Infection... 2012Mucus colonization is an essential early step toward establishing successful infection and disease by mucosal pathogens. There is an emerging literature implicating... (Review)
Review
Mucus colonization is an essential early step toward establishing successful infection and disease by mucosal pathogens. There is an emerging literature implicating specific mucin sub-types and mucin modifications in protecting the host from Campylobacter jejuni infection. However, mucosal pathogens have evolved sophisticated mechanisms to breach the mucus layer and C. jejuni in particular appears to harbor specific adaptations to better colonize intestinal mucus. For example, components of mucus are chemotactic for C. jejuni and the rheological properties of mucus promote motility of the organism. Furthermore, recent studies demonstrate that mucins modulate the pathogenicity of C. jejuni in a species-specific manner and likely help determine whether these bacteria become pathogenic (as in humans), or adopt a commensal mode of existence (as in chickens and other animals). This review focuses on recent advances in understanding the complex interplay between C. jejuni and components of the mucus layer.
Topics: Animals; Campylobacter jejuni; Host-Pathogen Interactions; Humans; Intestinal Mucosa; Mucus
PubMed: 22919607
DOI: 10.3389/fcimb.2012.00015 -
Journal of Biomedical Science May 2024Campylobacter jejuni is a very common cause of gastroenteritis, and is frequently transmitted to humans through contaminated food products or water. Importantly, C.... (Review)
Review
Campylobacter jejuni is a very common cause of gastroenteritis, and is frequently transmitted to humans through contaminated food products or water. Importantly, C. jejuni infections have a range of short- and long-term sequelae such as irritable bowel syndrome and Guillain Barre syndrome. C. jejuni triggers disease by employing a range of molecular strategies which enable it to colonise the gut, invade the epithelium, persist intracellularly and avoid detection by the host immune response. The objective of this review is to explore and summarise recent advances in the understanding of the C. jejuni molecular factors involved in colonisation, invasion of cells, collective quorum sensing-mediated behaviours and persistence. Understanding the mechanisms that underpin the pathogenicity of C. jejuni will enable future development of effective preventative approaches and vaccines against this pathogen.
Topics: Campylobacter jejuni; Virulence Factors; Humans; Campylobacter Infections; Quorum Sensing
PubMed: 38693534
DOI: 10.1186/s12929-024-01033-6 -
Antimicrobial Resistance Gene Transfer from Campylobacter jejuni in Mono- and Dual-Species Biofilms.Applied and Environmental Microbiology Jul 2021Horizontal gene transfer (HGT) is a driving force for the dissemination of antimicrobial resistance (AMR) genes among Campylobacter jejuni organisms, a leading cause of...
Horizontal gene transfer (HGT) is a driving force for the dissemination of antimicrobial resistance (AMR) genes among Campylobacter jejuni organisms, a leading cause of foodborne gastroenteritis worldwide. Although HGT is well documented for C. jejuni planktonic cells, the role of C. jejuni biofilms in AMR spread that likely occurs in the environment is poorly understood. Here, we developed a cocultivation model to investigate the HGT of chromosomally encoded AMR genes between two C. jejuni F38011 AMR mutants in biofilms. Compared to planktonic cells, C. jejuni biofilms significantly promoted HGT (0.05), resulting in an increase of HGT frequencies by up to 17.5-fold. Dynamic study revealed that HGT in biofilms increased at the early stage (i.e., from 24 h to 48 h) and remained stable during 48 to 72 h. Biofilms continuously released the HGT mutants into supernatant culture, indicating spontaneous dissemination of AMR to broader niches. DNase I treatment confirmed the role of natural transformation in genetic exchange. HGT was not associated with biofilm biomass, cell density, or bacterial metabolic activity, whereas the presence of extracellular DNA was negatively correlated with the altered HGT frequencies. HGT in biofilms also had a strain-to-strain variation. A synergistic HGT effect was observed between C. jejuni with different genomic backgrounds (i.e., C. jejuni NCTC 11168 chloramphenicol-resistant strain and F38011 kanamycin-resistant strain). C. jejuni performed HGT at the frequency of 10 in Escherichia coli-C. jejuni biofilms, while HGT was not detectable in Salmonella entericaC. jejuni biofilms. Antimicrobial-resistant C. jejuni has been listed as a high priority of public health concern worldwide. To tackle the rapid evolution of AMR in C. jejuni, it is of great importance to understand the extent and characteristics of HGT in C. jejuni biofilms, which serve as the main survival strategy of this microbe in the farm-to-table continuum. In this study, we demonstrated that biofilms significantly enhanced HGT compared to the planktonic state (0.05). Biofilm cultivation time and extracellular DNA (eDNA) amount were related to varied HGT frequencies. C. jejuni could spread AMR genes in both monospecies and dual-species biofilms, mimicking the survival mode of C. jejuni in food chains. These findings indicated that the risk and extent of AMR transmission among C. jejuni organisms have been underestimated, as previous HGT studies mainly focused on the planktonic state. Future AMR controlling measures can target biofilms and their main component eDNA.
Topics: Biofilms; Campylobacter jejuni; DNA, Bacterial; Drug Resistance, Bacterial; Gene Transfer, Horizontal
PubMed: 33990313
DOI: 10.1128/AEM.00659-21 -
Applied and Environmental Microbiology Sep 2014Campylobacter jejuni is one of the most frequent causes of bacterial gastrointestinal food-borne infection worldwide. This species is part of the normal flora of the... (Review)
Review
Campylobacter jejuni is one of the most frequent causes of bacterial gastrointestinal food-borne infection worldwide. This species is part of the normal flora of the gastrointestinal tracts of animals used for food production, including poultry, which is regarded as the primary source of human Campylobacter infections. The survival and persistence of C. jejuni in food processing environments, especially in poultry processing plants, represent significant risk factors that contribute to the spread of this pathogen through the food chain. Compared to other food-borne pathogens, C. jejuni is more fastidious in its growth requirements and is very susceptible to various environmental stressors. Biofilm formation is suggested to play a significant role in the survival of C. jejuni in the food production and processing environment. The aims of this minireview were (i) to examine the evidence that C. jejuni forms biofilms and (ii) to establish the extent to which reported and largely laboratory-based studies of C. jejuni biofilms provide evidence for biofilm formation by this pathogen in food processing environments. Overall existing studies do not provide strong evidence for biofilm formation (as usually defined) by most C. jejuni strains in food-related environments under the combined conditions of atmosphere, temperature, and shear that they are likely to encounter. Simple attachment to and survival on surfaces and in existing biofilms of other species are far more likely to contribute to C. jejuni survival in food-related environments based on our current understanding of this species.
Topics: Animals; Biofilms; Campylobacter jejuni; Environmental Microbiology; Food Microbiology; Microbial Viability
PubMed: 24928882
DOI: 10.1128/AEM.01493-14