Campylobacteriosis is a dominant bacterial cause of foodborne infection and is considered the main public health problem in Europe and many other countries worldwide. In the study lasting from 2011 ...to 2013 we compared the prevalence and antimicrobial resistance of Campylobacter jejuni and Campylobacter coli isolated from children, domestic animals, poultry meat and surface water in Northern Poland.
During a 3-years study 1973 samples were analysed. The results proved the presence of Campylobacter spp. in 306 (15.5%) samples. The percentage of Campylobacter-positive samples differed among the sample types, from 0% (freshwater beaches) to 38.6% (poultry meat in 2011). Prevalence of Campylobacter spp. in children isolates was 9.6%. It decreased from 13.2% in 2011 to 8.0% in 2013. It should be highlighted with a particular concern that Campylobacter jejuni was detected in 20.0% of fountains. All children and poultry meat isolates were susceptible to azithromycin. Two C. coli (3.7%) and four C. jejuni (3.3%) isolated from poultry meat were resistant to erythromycin. The highest percentage of C. jejuni isolates with resistance to ciprofloxacin were found in samples from 80% dogs and 85% ponds. Among isolates resistant to two antimicrobials 74.7% C. jejuni and 59.2% C. coli isolates were resistant to ciprofloxacin as well as to tetracycline. Only one cat C. coli isolate was resistant to both azithromycin and erythromycin. One C. jejuni isolate from a fountain was resistant to four antimicrobial agents (erythromycin, azithromycin, tetracycline and ciprofloxacin).
The study proved that surface water, poultry meat and pets constituted potential sources of Campylobacter to children. Fountains can be a direct source of children campylobacteriosis but can also pollute other environments with multidrug-resistant Campylobacter. The high resistance to some antimicrobials among the isolates may lead to increasing numbers of difficult-to-treat campylobacteriosis cases among children.
Guillain–Barré syndrome (GBS) is a post-infectious disease in which the human peripheral nervous system is affected after infection by specific pathogenic bacteria, including
Campylobacter jejuni
. ...GBS is suggested to be provoked by molecular mimicry between sialylated lipooligosaccharide (LOS) structures on the cell envelope of these bacteria and ganglioside epitopes on the human peripheral nerves, resulting in autoimmune-driven nerve destruction. Earlier, the
C. jejuni
sialyltransferase (Cst-II) was found to be linked to GBS and demonstrated to be involved in the biosynthesis of the ganglioside-like LOS structures. Apart from a role in pathogenicity, we report here that Cst-II-generated ganglioside-like LOS structures confer efficient bacteriophage resistance in
C. jejuni
. By bioinformatic analysis, it is revealed that the presence of sialyltransferases in
C. jejuni
and other potential GBS-related pathogens correlated significantly with the apparent degeneration of an alternative anti-virus system: type II
C
lusters of
R
egularly
I
nterspaced
S
hort
P
alindromic
R
epeat and
as
sociated genes (CRISPR-Cas). Molecular analysis of the
C. jejuni
CRISPR-Cas system confirmed the bioinformatic investigation. CRISPR degeneration and mutations in the
cas
genes
cas2
,
cas1
and
csn1
were found to correlate with Cst-II sialyltransferase presence (
p
< 0.0001). Remarkably, type II CRISPR-Cas systems are mainly found in mammalian pathogens. To study the potential involvement of this system in pathogenicity, we inactivated the type II CRISPR-Cas marker gene
csn1
, which effectively reduced virulence in primarily
cst
-II-positive
C. jejuni
isolates. Our findings indicate a novel link between viral defence, virulence and GBS in a pathogenic bacterium.
Campylobacter jejuni is a leading cause of food-borne gastroenteritis in humans. It lives commensally in the gastrointestinal tract of animals, and tolerates variable conditions during ...transit/colonization of susceptible hosts. The C. jejuniCprRS two-component system contains an essential response regulator (CprR), and deletion of the cprS sensor kinase enhances biofilms. We sought to identify CprRS-regulated genes and better understand how the system affects survival. Expression from the cprR promoter was highest during logarithmic growth and dependent on CprS. CprRD52A did not support viability, indicating that CprR phosphorylation is essential despite the dispensability of CprS. We identified a GTAAAC consensus bound by the CprR C-terminus; the Asp52 residue of full-length CprR was required for binding, suggesting phosphorylation is required. Transcripts differing in expression in Delta cprS compared with wildtype (WT) contained a putative CprR binding site upstream of their promoter region and encoded htrA (periplasmic protease upstream of cprRS) and peb4 (SurA-like chaperone). Consistent with direct regulation, the CprR consensus in the htrA promoter was bound by CprRCTD. Finally, Delta htrA formed enhanced biofilms, and Delta cprS biofilms were suppressed by Mg2+. CprRS is the first C. jejuni regulatory system shown to control genes related to the cell envelope, the first line of interaction between pathogen and changing environments. Campylobacter jejuni is a leading cause of food-borne illness, and understanding how it adapts to different environments is key to infection control. Here, we characterize the activity, regulation, and regulon of the conserved C. jejuni two-component regulatory system, CprRS. We find that response regulator phosphorylation, like the regulator itself, is essential for viability, and that the system regulates processes and genes related to the cell envelope, including the htrA periplasmic serine protease.
Campylobacter jejuni is one of the major causes of bacterial gastrointestinal disease in humans worldwide. This foodborne pathogen colonizes the intestinal tracts of chickens, and consumption of ...chicken and poultry products is identified as a common route of transmission. We analyzed two C. jejuni strains after oral challenge with 105 CFU/ml of C. jejuni per chick; one strain was a robust colonizer (A74/C) and the other a poor colonizer (A74/O). We also found extensive phenotypic differences in growth rate, biofilm production, and in vitro adherence, invasion, intracellular survival, and transcytosis. Strains A74/C and A74/O were genotypically similar with respect to their whole genome alignment, core genome, and ribosomal MLST, MLST, flaA, porA, and PFGE typing. The global proteomes of the two congenic strains were quantitatively analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and 618 and 453 proteins were identified from A74/C and A74/O isolates, respectively. Cluster of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed that carbon metabolism and motility proteins were distinctively overexpressed in strain A74/C. The robust colonizer also exhibited a unique proteome profile characterized by significantly increased expression of proteins linked to adhesion, invasion, chemotaxis, energy, protein synthesis, heat shock proteins, iron regulation, two-component regulatory systems, and multidrug efflux pump. Our study underlines phenotypic, genotypic, and proteomic variations of the poor and robust colonizing C. jejuni strains, suggesting that several factors may contribute to mediating the different colonization potentials of the isogenic isolates.
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•The study focuses on two distinct C. jejuni strains, one identified as a robust colonizer (A74/C) and the other as a poor colonizer (A74/O). These strains were subjected to detailed analysis following oral challenge in a chick model.•The research reveals striking phenotypic differences between A74/C and A74/O, including variations in growth rate, biofilm production, and in vitro behaviors such as adherence, invasion, intracellular survival, and transcytosis.•Despite their phenotypic differences, the two strains A74/C and A74/O exhibited genotypic similarity as evidenced by whole genome alignment, core genome analysis, and multiple typing methods (MLST, flaA, porA, PFGE).•A comprehensive proteomic analysis was conducted using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), resulting in the identification of 618 and 453 proteins from A74/C and A74/O isolates, respectively.•The proteomic data revealed distinct profiles for the two strains. Strain A74/C showed significant overexpression of proteins associated with adhesion, invasion, chemotaxis, energy production, protein synthesis, heat shock response, iron regulation, two-component regulatory systems, and multidrug efflux pumps.•The study underscores the importance of considering both phenotypic and proteomic variations when assessing the colonization potential of C. jejuni strains. It suggests that multiple factors may contribute to the observed differences in colonization abilities between these isogenic isolates.
promotes commensalism in the intestinal tracts of avian hosts and diarrheal disease in humans, yet components of intestinal environments recognized as spatial cues specific for different intestinal ...regions by the bacterium to initiate interactions in either host are mostly unknown. By analyzing a
acetogenesis mutant defective in converting acetyl coenzyme A (Ac-CoA) to acetate and commensal colonization of young chicks, we discovered evidence for
microbiota-derived short-chain fatty acids (SCFAs) and organic acids as cues recognized by
that modulate expression of determinants required for commensalism. We identified a set of
genes encoding catabolic enzymes and transport systems for amino acids required for
growth whose expression was modulated by SCFAs. Transcription of these genes was reduced in the acetogenesis mutant but was restored upon supplementation with physiological concentrations of the SCFAs acetate and butyrate present in the lower intestinal tracts of avian and human hosts. Conversely, the organic acid lactate, which is abundant in the upper intestinal tract where
colonizes less efficiently, reduced expression of these genes. We propose that microbiota-generated SCFAs and lactate are cues for
to discriminate between different intestinal regions. Spatial gradients of these metabolites likely allow
to locate preferred niches in the lower intestinal tract and induce expression of factors required for intestinal growth and commensal colonization. Our findings provide insights into the types of cues
monitors in the avian host for commensalism and likely in humans to promote diarrheal disease.
is a commensal of the intestinal tracts of avian species and other animals and a leading cause of diarrheal disease in humans. The types of cues sensed by
to influence responses to promote commensalism or infection are largely lacking. By analyzing a
acetogenesis mutant, we discovered a set of genes whose expression is modulated by lactate and short-chain fatty acids produced by the microbiota in the intestinal tract. These genes include those encoding catabolic enzymes and transport systems for amino acids that are required by
for
growth and intestinal colonization. We propose that gradients of these microbiota-generated metabolites are cues for spatial discrimination between areas of the intestines so that the bacterium can locate niches in the lower intestinal tract for optimal growth for commensalism in avian species and possibly infection of human hosts leading to diarrheal disease.
Campylobacter jejuni is a microaerophilic foodborne pathogen that is sensitive to stress conditions. However, it is not yet understood how this stress-sensitive pathogen may cause a significant ...number of cases of human gastroenteritis worldwide. In this study, we examined stress tolerance in 70 C. jejuni strains isolated from retail chicken under several stress conditions related to food safety. Compared to oxygen-sensitive (OS) strains of C. jejuni, C. jejuni strains with increased aerotolerance, such as hyper-aerotolerant (HAT) and aerotolerant (AT) strains, were more tolerant to peracetic acid, refrigeration and freeze-thaw stresses. However, the levels of thermotolerance and hyper-osmotolerance were not associated with the aerotolerance level of C. jejuni. The HAT and AT strains of C. jejuni exhibited significantly increased activities of catalase and superoxide dismutase (SOD), compared to the OS strains. Consistently, the HAT and AT strains were highly tolerant to oxidants, such as hydrogen peroxide, cumene hydroperoxide and menadione, compared to the OS strains. The AT and HAT strains that were tolerant to stresses, particularly peracetic acid and refrigeration, predominantly belonged to multilocus sequence typing (MLST) clonal complex (CC)-21. This study shows that oxidative stress resistance plays a role in determining the differential level of aerotolerance in C. jejuni and that AT and HAT strains of C. jejuni are more tolerant to oxidants and low temperatures than OS strains.
Campylobacter jejuni, a common foodborne zoonotic pathogen, causes gastroenteritis worldwide and is increasingly resistant to antibiotics. We aimed to investigate the antimicrobial resistance (AMR) ...genotypes of C. jejuni isolated from humans, poultry and birds from wild and urban Italian habitats to identify correlations between phenotypic and genotypic AMR in the isolates. Altogether, 644 C. jejuni isolates from humans (51), poultry (526) and wild- and urban-habitat birds (67) were analysed. The resistance phenotypes of the isolates were determined using the microdilution method with EUCAST breakpoints, and AMR-associated genes and single nucleotide polymorphisms were obtained from a publicly available database. Antimicrobial susceptibility testing showed that C. jejuni isolates from poultry and humans were highly resistant to ciprofloxacin (85.55% and 76.47%, respectively), nalidixic acid (75.48% and 74.51%, respectively) and tetracycline (67.87% and 49.02%, respectively). Fewer isolates from the wild- and urban-habitat birds were resistant to tetracycline (19.40%), fluoroquinolones (13.43%), and quinolone and streptomycin (10.45%). We retrieved seven AMR genes (tet (O), cmeA, cmeB, cmeC, cmeR, blaOXA-61 and blaOXA-184) and gyrA-associated point mutations. Two major B-lactam genes called blaOXA-61 and blaOXA-184 were prevalent at 62.93% and 82.08% in the poultry and the other bird groups, respectively. Strong correlations between genotypic and phenotypic resistance were found for fluoroquinolones and tetracycline. Compared with the farmed chickens, the incidence of AMR in the C. jejuni isolates from the other bird groups was low, confirming that the food-production birds are much more exposed to antimicrobials. The improper and overuse of antibiotics in the human population and in animal husbandry has resulted in an increase in antibiotic-resistant infections, particularly fluoroquinolone resistant ones. Better understanding of the AMR mechanisms in C. jejuni is necessary to develop new strategies for improving AMR programs and provide the most appropriate therapies to human and veterinary populations.
Previous studies have identified a specific modification of the capsular polysaccharide as receptor for phages that infect Campylobacter jejuni. Using acapsular kpsM mutants of C. jejuni strains ...NCTC11168 and NCTC12658, we found that bacteriophage F341 infects C. jejuni independently of the capsule. In contrast, phage F341 does not infect C. jejuni NCTC11168 mutants that either lack the flagellar filaments (ΔflaAB) or that have paralyzed, i.e., nonrotating, flagella (ΔmotA and ΔflgP). Complementing flgP confirmed that phage F341 requires rotating flagella for successful infection. Furthermore, adsorption assays demonstrated that phage F341 does not adsorb to these nonmotile C. jejuni NCTC11168 mutants. Taken together, we propose that phage F341 uses the flagellum as a receptor. Phage-host interactions were investigated using fluorescence confocal and transmission electron microscopy. These data demonstrate that F341 binds to the flagellum by perpendicular attachment with visible phage tail fibers interacting directly with the flagellum. Our data are consistent with the movement of the C. jejuni flagellum being required for F341 to travel along the filament to reach the basal body of the bacterium. The initial binding to the flagellum may cause a conformational change of the phage tail that enables DNA injection after binding to a secondary receptor.
Phase variation (PV) creates phenotypic heterogeneity at high frequencies and in a reversible manner. This phenomenon allows bacteria to adapt to a variety of different environments and selective ...pressures. In Campylobacterjejuni this reversible adaptive process is mediated by mutations in homopolymeric G/C tracts. Many C. jejuni-specific phages are dependent on phase-variable surface structures for successful infection. We previously identified the capsular polysaccharide (CPS) moiety, MeOPN-GalfNAc, as a receptor for phage F336 and showed that phase-variable expression of the transferase for this CPS modification, cj1421, and two other phase-variable CPS genes generated phage resistance in C. jejuni. Here we investigate the population dynamics of C. jejuni NCTC11168 when exposed to phage F336 in vitro using a newly described method - the 28-locus-CJ11168 PV analysis. Dynamic switching was observed in the ON/OFF states of three phase-variable CPS genes, cj1421, cj1422 and cj1426, during phage F336 exposure, with the dominant phage-resistant phasotype differing between cultures. Although loss of the phage receptor was predominately observed, several other PV events also led to phage resistance, a phenomenon that increases the chance of phage-resistant subpopulations being present in any growing culture. No other PV genes were affected and exposure to phage F336 resulted in a highly specific response, only selecting for phase variants of cj1421, cj1422 and cj1426. In summary, C. jejuni may benefit from modification of the surface in multiple ways to inhibit or reduce phage binding, thereby ensuring the survival of the population when exposed to phages.
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