Genomic diversity of Campylobacter coli and Campylobacter jejuni isolates recovered from free-range broiler farms and comparison with isolates of various origins

Phenotypic, genotypic and proteomic variations between poor and robust colonizing Campylobacter jejuni strains

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.

Exploring the influence of slaughterhouse type and slaughtering steps on Campylobacter jejuni contamination in chicken meat: A cluster analysis approach

Campylobacter jejuni (C. jejuni), a foodborne pathogen, poses notable hazards to human health and has significant economic implications for poultry production. This study aimed to assess C. jejuni contamination levels in chicken carcasses from both backyard and commercial slaughterhouses in Chiang Mai province, Thailand. It also sought to examine the effects of different slaughtering practices on contamination levels and to offer evidence-based recommendations for reducing C. jejuni contamination. Through the sampling of 105 chicken carcasses and subsequent enumeration of C. jejuni, the study captured the impact of various slaughtering practices. Utilizing k-modes clustering on the observational and bacterial count data, the research identified distinct patterns of contamination, revealing higher levels in backyard operations compared to commercial ones. The application of k-modes clustering highlighted the impact of critical slaughtering practices, particularly chilling, on contamination levels. Notably, samples with the lowest bacterial counts were typically from the chilling step, a practice predominantly found in commercial facilities. This observation underpins the recommendation for backyard slaughterhouses to incorporate ice in their post-evisceration soaking process. Mimicking commercial practices, this chilling method aims to inhibit C. jejuni growth by reducing carcass temperature, thereby enhancing food safety. Furthermore, the study suggests backyard operations adopt additional measures observed in commercial settings, like segregating equipment for each slaughtering step and implementing regular cleaning protocols. These strategic interventions are pivotal in reducing contamination risks, advancing microbiological safety in poultry processing, and aligning with global food safety enhancement efforts.

Analysis of reservoir sources of Campylobacter isolates to free-range broilers in Denmark

Campylobacter is a common cause of food poisoning in many countries, with broilers being the main source. Organic and free-range broilers are more frequently Campylobacter-positive than conventionally raised broilers and may constitute a higher risk for human infections. Organic and free-range broilers may get exposed to Campylobacter from environmental reservoirs and livestock farms, but the relative importance of these sources is unknown. The aim of the study was to describe similarities and differences between the genetic diversity of the Campylobacter isolates collected from free-range/organic broilers with those isolated from conventional broilers and other animal hosts (cattle, pigs, and dogs) in Denmark to make inferences about the reservoir sources of Campylobacter to free-range broilers. The applied aggregated surveillance data consisted of sequenced Campylobacter isolates sampled in 2015 to 2017 and 2018 to 2021. The data included 1,102 isolates from free-range (n = 209), conventional broilers (n = 577), cattle (n = 261), pigs (n = 30), and dogs (n = 25). The isolates were cultivated from either fecal material (n = 434), food matrices (n = 569), or of nondisclosed origin (n = 99). Campylobacter jejuni (94.5%) dominated and subtyping analysis found 170 different sequence types (STs) grouped into 75 clonal complexes (CCs). The results suggest that CC-21 and CC-45 are the most frequent CCs found in broilers. The relationship between the CCs in the investigated sources showed that the different CCs were shared by most of the animals, but not pigs. The ST-profiles of free-range broilers were most similar to that of conventional broilers, dogs and cattle, in that order. The similarity was stronger between conventional broilers and cattle than between conventional and free-range broilers. The results suggest that cattle may be a plausible reservoir of C. jejuni for conventional and free-range broilers, and that conventional broilers are a possible source for free-range broilers or reflect a dominance of isolates adapted to the same host environment. Aggregated data provided valuable insight into the epidemiology of Campylobacter sources for free-range broilers, but time-limited sampling of isolates from different sources within a targeted area would hold a higher predictive value.

Demographic, Husbandry, and Biosecurity Factors Associated with the Presence of Campylobacter spp. in Small Poultry Flocks in Ontario, Canada

This study is part of a 2 year disease surveillance project conducted to establish the prevalence of poultry and zoonotic pathogens, including Campylobacter spp., among small poultry flocks in Ontario, Canada. For each post-mortem submission to the Animal Health Laboratory, a pooled sample of cecal tissue was cultured for Campylobacter spp., and a husbandry and biosecurity questionnaire was completed by the flock owner (n = 153). Using both laboratory and questionnaire data, our objective was to investigate demographic, husbandry, and biosecurity factors associated with the presence of Campylobacter spp. in small flocks. Two multivariable logistic regression models were built. In the farm model, the odds of Campylobacter spp. were higher in turkeys, and when birds were housed in a mixed group with different species and/or types of birds. The odds were lower when antibiotics were used within the last 12 months, and when birds had at least some free-range access. The effect of pest control depended on the number of birds at risk. In the coop model, the odds of Campylobacter spp. were lower when owners wore dedicated clothing when entering the coop. These results can be used to limit the transmission of Campylobacter spp. from small poultry flocks to humans.

Approaches to prevent and control Campylobacter spp. colonization in broiler chickens: a review

Campylobacter, Gram-negative bacteria, is the most common cause of acute bacterial enteritis in human beings, both in developing and developed countries. It is believed that poultry, in particular broiler chickens, is the main host of human infection with Campylobacter. Handling and consumption of contaminated chicken meat are the usual modes of transmission. Prevention and reduction of Campylobacter colonization in poultry farms will cut off the road of infection transmission to humans throughout the food chain. With the incidence of antibiotic resistance and with growing concern about superbugs, the search for natural and safe alternatives will considerably increase in the coming years. In this review, we will discuss the prevalence and risk factors of Campylobacter colonization in broiler chickens and sources of infection. This review also provides extensive and recent approaches to prevent and control Campylobacter colonization in broiler chickens, including biosecurity measures, natural feed/drinking water additives with antimicrobial properties, bacteriocins, bacteriophages, antimicrobial peptides, and vaccination strategies to prevent and control the incidence of human campylobacteriosis.

Longitudinal Study of the Distribution of Antimicrobial-Resistant Campylobacter Isolates from an Integrated Broiler Chicken Operation

The aim of this study was to analyze the prevalence, antimicrobial resistance, and genetic diversity of Campylobacter isolates that were obtained from whole chicken production stages in Korea. A total of 1348 samples were collected from 10 production lines. The prevalence of Campylobacter in breeder farm, broiler farm, slaughterhouse, and retail meat products was 50.0%, 3.3%, 13.4%, and 68.4%, respectively, and Campylobacter was not detected at the hatchery stage. Resistance to quinolones/fluoroquinolones was the most prevalent at all stages. Among the multidrug-resistant isolates, 16 isolates (19.8%) from breeder farm were resistant to both azithromycin and ciprofloxacin. A total of 182 isolates were subdivided into 82 pulsed-field gel electrophoresis (PFGE) genotypes with 100% similarity. Diverse genotypes were presented with discontinuous patterns along the whole production chain. Thirty percent of Campylobacter-free flocks became positive after slaughtering. An identical genotype was simultaneously detected from both breeder farm and retail meat, even from different production lines. This study reveals that antimicrobial-resistant Campylobacter contamination can occur at all stages of the chicken supply chain. In particular, the breeder farm and slaughterhouse should be the main control points, as they are the potential stages at which antimicrobial-resistant Campylobacter could spread to retail meat products by horizontal transmission.

Horizontal genetic exchange of chromosomally encoded markers between Campylobacter jejuni cells

Many epidemiological studies provide us with the evidence of horizontal gene transfer (HGT) contributing to the bacterial genomic diversity that benefits the bacterial populations with increased ability to adapt to the dynamic environments. Campylobacter jejuni, a major cause of acute enteritis in the U.S., often linked with severe post-infection neuropathies, has been reported to exhibit a non-clonal population structure and comparatively higher strain-level genetic variation. In this study, we provide evidence of the HGT of chromosomally encoded genetic markers between C. jejuni cells in the biphasic MH medium. We used two C. jejuni NCTC-11168 mutants harbouring distinct antibiotic-resistance genes [chloramphenicol (Cm) and kanamycin (Km)] present at two different neutral genomic loci. Cultures of both marker strains were mixed together and incubated for 5 hrs, then plated on MH agar plates supplemented with both antibiotics. The recombinant cells with double antibiotic markers were generated at the frequency of 0.02811 ± 0.0035% of the parental strains. PCR assays using locus-specific primers confirmed that transfer of the antibiotic-resistance genes was through homologous recombination. Also, the addition of chicken cecal content increased the recombination efficiency approximately up to 10-fold as compared to the biphasic MH medium (control) at P < 0.05. Furthermore, treating the co-culture with DNase I decreased the available DNA, which in turn significantly reduced recombination efficiency by 99.92% (P < 0.05). We used the cell-free supernatant of 16 hrs-culture of Wild-type C. jejuni as a template for PCR and found DNA sequences from six different genomic regions were easily amplified, indicating the presence of released chromosomal DNA in the culture supernatant. Our findings suggest that HGT in C. jejuni is facilitated in the chicken gut environment contributing to in vivo genomic diversity. Additionally, C. jejuni might have an active mechanism to release its chromosomal DNA into the extracellular environment, further expediting HGT in C. jejuni populations.

Quantitative approach to assess the compliance to a performance objective (PO) of Campylobacter jejuni in poultry meat in France

Predictive modelling is used in microbiological risk assessment to quantify the growth and inactivation of microorganisms through the use of mathematical models. Campylobacter jejuni is one of the main foodborne pathogens and broiler meat is considered as the most important source of human campylobacteriosis. The purpose of this study was to assess the effects of heating and chilling during the poultry slaughter process on inactivation kinetics of Campylobacter jejuni during chilled storage in order to predict its contamination level prior to preparation and consumption in the consumer's home, and then to assess the compliance to a Performance Objective (PO). Three strains of C. jejuni were submitted to consecutive heat (54 °C for 3 min) and cold (3 °C for 2 h) stresses, mimicking the two main slaughtering steps, i.e. scalding and chilling, by inoculating chicken fillets with three different concentrations (4, 6 and 8 log₁₀ CFU/g). Fillets were then stored at 6 °C during 17 days under the modified atmosphere currently used by food processors (70% O₂/30% CO₂). For all strains, bacterial log reduction was the lowest when inoculated at 8 log₁₀ CFU/g. One strain showed an enhanced resistance during cold storage after application of stressing steps, suggesting an impact of the cell history on further bacterial resistance. Taking strain variability into account, after six days of storage, predictions showed compliance of ready-to-be-cooked chicken meat with a hypothetical PO of 2.55 log₁₀ CFU/g, value set before the meat enters the consumer's home by the ICMSF (International Commission on Microbiological Specifications for Foods). This study opens the path to assess the compliance to a PO of Campylobacter jejuni in poultry meat and more generally provides inputs to refine microbiological risk assessment by taking into account the cell history and more particularly the impact of stressful steps on the subsequent inactivation at consumer's home.

On farm interventions to minimise Campylobacter spp. contamination in chicken

1. This review explores current and proposed on-farm interventions and assess the potential of these interventions against Campylobacter spp. 2. Interventions such as vaccination, feed/water-additives and, most importantly, consistent biosecurity, exhibit potential for the effective control of this pathogen and its dissemination within the food chain. 3. Due to the extensive diversity in the Campylobacter spp. genome and surface-expressed proteins, vaccination of poultry is not yet regarded as a completely effective strategy. 4. The acidification of drinking water through the addition of organic acids has been reported to decrease the risk of Campylobacter spp. colonisation in broiler flocks. Whilst this treatment alone will not completely protect birds, use of water acidification in combination with in-feed measures to further reduce the level of Campylobacter spp. colonisation in poultry may be an option meriting further exploration. 5. The use of varied types of feed supplements to reduce the intestinal population and shedding rate of Campylobacter spp. in poultry is an area of growing interest in the poultry industry. Such supplements include pro - and pre-biotics, organic acids, bacteriocins and bacteriophage, which may be added to feed and water. 6. From the literature, it is clear that a distinct, albeit not unexpected, difference between the performance of in-feed interventions exists when examined in vitro compared to those determined in in vivo studies. It is much more likely that pooling some of the discussed approaches in the in-feed tool kit will provide an answer. 7. Whilst on-farm biosecurity is essential to maintain a healthy flock and reduce disease transmission, even the most stringent biosecurity measures may not have sufficient, consistent and predictable effects in controlling Campylobacter spp. Furthermore, the combination of varied dietary approaches and improved biosecurity measures may synergistically improve control.

Comparison of PCR-RFLP and PFGE for determining the clonality of Brucella isolates from human and livestock specimens

Brucellosis is an important zoonotic disease caused by different species of genus Brucella that are pathogenic for humans and a variety of animals. Accurate detection of Brucella spp. infection is important for control of disease. The aim of this study was to comparison of molecular genotyping of Brucella strains by Pulsed-field gel electrophoresis (PFGE) and polymerase chain reaction -Restriction Fragment Length Polymorphism (PCR-RFLP) techniques. Twenty- seven Brucella spp. were isolated from human and animal samples. The isolates identified by conventional microbiological methods and confirmed using PCR for amplification of omp2a gene. Molecular typing of Brucella strains carried out by PCR-RFLP after PstI and PFGE of chromosomal DNA after XbaI enzyme digestion. The omp2a gene PCR Products with different patterns of PCR-RFLP were sequenced. The omp2a gene amplification of all human and animal Brucella isolates were positive for 1100 bp fragment. By PCR-RFLP analysis two genotypes/patterns for human isolates and four genotypes for animal isolates were obtained. In PFGE analysis totally, 7 common clones/clusters and 3 single clones were obtained. The results of this study showed the PFGE method is the more reliable and useful assay for molecular typing of Brucella strains and is more preferred to PCR-RFLP in determination of genetic similarity among human and animal Brucella isolates. The presented data showed PCR-RFLP analysis was not able to differentiate between B. melitensis biovars and vaccine strain.

A representative overview of the genetic diversity and lipooligosaccharide sialylation in Campylobacter jejuni along the broiler production chain in France and its comparison with human isolates

Campylobacter jejuni is the most common cause of bacterial gastroenteritis worldwide and is associated with post-infectious neuropathies. Moreover, the chicken reservoir is described as the main source of human infection and C. jejuni sialylated lipooligosaccharides seem to play an important role in the pathogenesis of neuropathies. In this study, MultiLocus Sequence Typing (MLST) and Comparative Genomic Fingerprinting using 40 assay genes (CGF40) were used to describe C. jejuni populations within clinical isolates and a representative collection of isolates from French poultry production. In addition, the sialylation of C. jejuni LOS was assessed. Here, we report high levels of genetic diversity among both chicken and human disease C. jejuni populations. The predominance of the ST-21, ST-45, and ST-464 complexes in chicken isolates and of the ST-21, ST-206, and ST-48 complexes in the clinical isolates was observed as were correlations between some MLST and CGF40 genotypes. Furthermore, some C. jejuni genotypes were frequently isolated among clinical cases as well as all along the broiler production chain, suggesting a potentially high implication of chicken in human campylobacteriosis in France. Finally, the LOS classes A, B and C were predominant within clinical C. jejuni isolates supporting the hypothesis of a benefit in infectivity for C. jejuni isolates showing sialylated LOS.

Nanobodies targeting conserved epitopes on the major outer membrane protein of Campylobacter as potential tools for control of Campylobacter colonization

Campylobacter infections are among the most prevalent foodborne infections in humans, resulting in a massive disease burden worldwide. Broilers have been identified as the major source of campylobacteriosis and reducing Campylobacter loads in the broiler caeca has been proposed as an effective measure to decrease the number of infections in humans. Failure of current methods to control Campylobacter in broilers stresses the urgency to develop novel mitigation measures. We obtained six nanobodies with a broad specificity, that recognize strains belonging to the two most relevant species, Campylobacter jejuni and Campylobacter coli. The target of the nanobodies was identified as the major outer membrane protein, a porin that contributes to bacterial virulence and viability. Multimerization of the nanobodies led to agglutination of C. jejuni cells, which may affect colonization in the chicken gut. These Campylobacter-specific nanobodies may be useful to develop a strategy for preserving chickens from Campylobacter colonization.

Next generation microbiological risk assessment: opportunities of whole genome sequencing (WGS) for foodborne pathogen surveillance, source tracking and risk assessment

Whole genome sequencing (WGS) of important foodborne pathogens is a technology under development, but is already employed in routine surveillance by public health agencies and is being increasingly exploited in tracing transmission routes and identifying contamination events (source tracking) that take place in the farm-to-fork continuum. Furthermore, data generated from WGS, complemented by other -omics data, have the potential to be integrated into and strengthen microbiological risk assessment. In this paper, we discuss the contribution of WGS in diverse areas important to food safety and public health. Additionally, an outlook of future WGS applications, which should contribute to our understanding of the ecology and physiology of foodborne microorganisms, is presented.

No Clear Differences between Organic or Conventional Pig Farms in the Genetic Diversity or Virulence of Campylobacter coli Isolates

To evaluate the impact of pig farm management on the genetic diversity and on the virulence of Campylobacter coli, we characterized isolates from 19 organic pig farms (62 isolates) and from 24 conventional pig farms (58 isolates). The 120 C. coli isolates were typed using pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) and the presence of nine virulence genes was screened using real-time PCR. The capacity of adhesion and invasion of 61 isolates (32 from organic and 29 from conventional farms) were then tested on human intestinal Caco-2 cells. A total of 59 PFGE types and of 50 sequence types (STs) were identified. Twelve PFGE types and nine STs, accounting for 34 and 41.6% of the isolates, respectively, were common between the two production systems with ST854 dominating (18.3% of the isolates). Twenty-nine PFGE types and 25 STs were only found in isolates from organic farms, and 18 PFGE types and 16 STs from conventional farms. No significant differences were found in diversity despite the differences in rearing systems, except at the locus level for the glnA, gltA, and uncA genes. All isolates, regardless of their origin, carried the ceuE, iam, ciaB, and flaA genes and more than 95% of the isolates carried the cadF and cdtABC genes. No significant differences were found in pathogenicity between the two farming systems. The pathogenicity of the C. coli isolates was low compared to C. jejuni control strains tested. The plasmid gene virb11 was detected in only 13 isolates from organic farms; these isolates showed greater invasion capacity than those without this gene. Our study indicates that pig farm management does not significantly affect the diversity and the virulence of Campylobacter coli isolated from pigs. The common genotypes between conventional and organic farms may indicate that some genotypes are adapted to pigs.

Effect of Feed Additives on Productivity and Campylobacter spp. Loads in Broilers Reared under Free Range Conditions

The poultry reservoir, especially broiler meat, is generally recognized as one of the most-important sources for human Campylobacteriosis. The measures to control Campylobacter targeted essentially the primary production level. The aim of this work was to evaluate the effectiveness of different treatments against natural Campylobacter colonization in a French experimental farm of free-range broilers during the whole rearing period. Five commercial products and a combination of two of them were tested and all the products were added to feed or to water at the dose recommended by the suppliers. Campylobacter loads in caeca and on carcasses of broilers at the slaughter were determined by culture methods. Natural contamination of the flock occurred at the end of the indoor rearing period between day 35 and day 42. At day 42, the multispecies probiotic added to the feed reduced the contamination of 0.55 log10 CFU/g (p = 0.02) but was not significant (p > 0.05) at the end of rearing at day 78. However, another treatment, a combination of a cation exchange clay-based product in feed and an organic acid mixture (formic acid, sodium formate, lactic acid, propionic acid) in water, led to a slight but significant reduction of 0.82 ± 0.25 log10 CFU/g (p = 0.02) compared to the control group at day 78. Testing this combination in field conditions in several flocks is needed to determine if it is biologically relevant and if it could be a valuable measure to reduce Campylobacter in broiler flocks.

Isolation of Campylobacter spp. from Three Species of Antarctic Penguins in Different Geographic Locations

The presence of Campylobacter species was studied in three Antarctic penguin species, Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua). A total of 390 penguins were captured in 12 different rookeries along the Antarctic Peninsula with differences in the amount of human visitation: six colonies were highly visited [Stranger Point, King George Island (P. papua and P. adeliae); Hannah Point, Livingston Island (P. papua and P. antarctica); Deception Island (P. antarctica); and Paradise Bay, Antarctic Peninsula (P. papua)], and six colonies were rarely visited [Devil's Point, Byers Peninsula, Livingston Island (P. papua); Cierva Cove, Antarctic Peninsula (P. papua); Rongé Island (P. papua and P. antarctica); Yalour Island (P. adeliae); and Avian Island (P. adeliae)]. A total of 23 strains were isolated from penguins from nine different rookeries. Campylobacter lari subsp. lari was isolated from eight samples (seven from P. papua and one from P. adeliae); C. lari subsp. concheus from 13 (ten from P. adeliae and three from P. antarctica) and C. volucris from two samples (both from P. papua). We did not find any significant differences in the prevalence of Campylobacter spp. between the populations in highly and rarely visited areas. This is the first report of C. lari subsp. concheus and C. volucris isolation from penguins in the Antarctic region.

Genomic variations leading to alterations in cell morphology of Campylobacter spp

Campylobacter jejuni, the most common cause of bacterial diarrhoeal disease, is normally helical. However, it can also adopt straight rod, elongated helical and coccoid forms. Studying how helical morphology is generated, and how it switches between its different forms, is an important objective for understanding this pathogen. Here, we aimed to determine the genetic factors involved in generating the helical shape of Campylobacter. A C. jejuni transposon (Tn) mutant library was screened for non-helical mutants with inconsistent results. Whole genome sequence variation and morphological trends within this Tn library, and in various C. jejuni wild type strains, were compared and correlated to detect genomic elements associated with helical and rod morphologies. All rod-shaped C. jejuni Tn mutants and all rod-shaped laboratory, clinical and environmental C. jejuni and Campylobacter coli contained genetic changes within the pgp1 or pgp2 genes, which encode peptidoglycan modifying enzymes. We therefore confirm the importance of Pgp1 and Pgp2 in the maintenance of helical shape and extended this to a wide range of C. jejuni and C. coli isolates. Genome sequence analysis revealed variation in the sequence and length of homopolymeric tracts found within these genes, providing a potential mechanism of phase variation of cell shape.

Influence of enrichment and isolation media on the detection of Campylobacter spp. in naturally contaminated chicken samples

Investigating Campylobacter epidemiology requires adequate technique and media to ensure optimal culturing and accurate detection and isolation of Campylobacter strains. In the present study, we investigated the performances of three enrichment durations in Bolton broth (0, 24 and 48h) and compared four isolation media (mCCDA, Karmali, Butzler no. 2 and CampyFood agar (CFA)) for the detection of Campylobacter positive samples and the identification of Campylobacter species, from naturally contaminated broiler chicken samples (caeca, neck skin from carcasses, and skin from thighs). We compared our local results to those we obtained with samples from a European survey (caeca and neck skin) and a national survey (neck skin, thigh skin, and breast). Direct plating favored the detection of positive samples highly contaminated by Campylobacter (caeca and neck skin from carcasses) whatever the media. A longer enrichment reduced the rates of Campylobacter recovery except when using Butzler no. 2, more particularly for neck skin which background microflora was less important than in caeca. As a matter of fact, enrichment allowed a higher detection rate of positive samples with low Campylobacter contamination levels (breast, thigh skin), this detection being enhanced when using Butzler no. 2. When comparing the 3 other selective media, CFA was the 2nd most efficient media prior to mCCDA and Karmali. Interestingly, enrichment promoted the growth of Campylobacter coli but this promotion was least with Butzler no. 2 agar. Our study has confirmed the need to adapt the method to the types of samples for improving the detection of Campylobacter and that the method may affect the prevalence of the species.

Recent Advances in Screening of Anti-Campylobacter Activity in Probiotics for Use in Poultry

Campylobacteriosis is the most common cause of bacterial gastroenteritis worldwide. Campylobacter species involved in this infection usually include the thermotolerant species Campylobacter jejuni. The major reservoir for C. jejuni leading to human infections is commercial broiler chickens. Poultry flocks are frequently colonized by C. jejuni without any apparent symptoms. Risk assessment analyses have identified the handling and consumption of poultry meat as one of the most important sources of human campylobacteriosis, so elimination of Campylobacter in the poultry reservoir is a crucial step in the control of this foodborne infection. To date, the use of probiotics has demonstrated promising results to reduce Campylobacter colonization. This review provides recent insights into methods used for probiotic screening to reduce the prevalence and colonization of Campylobacter at the farm level. Different eukaryotic epithelial cell lines are employed to screen probiotics with an anti-Campylobacter activity and yield useful information about the inhibition mechanism involved. These in vitro virulence models involve only human intestinal or cervical cell lines whereas the use of avian cell lines could be a preliminary step to investigate mechanisms of C. jejuni colonization in poultry in the presence of probiotics. In addition, in vivo trials to evaluate the effect of probiotics on Campylobacter colonization are conducted, taking into account the complexity introduced by the host, the feed, and the microbiota. However, the heterogeneity of the protocols used and the short time duration of the experiments lead to results that are difficult to compare and draw conclusions at the slaughter-age of broilers. Nevertheless, the combined approach using complementary in vitro and in vivo tools (cell cultures and animal experiments) leads to a better characterization of probiotic strains and could be employed to assess reduced Campylobacter spp. colonization in chickens if some parameters are optimized.

Comparison of Antimicrobial Susceptibility of Campylobacter Strains Isolated from Food Samples and Patients with Diarrhea

BACKGROUND

Campylobacter infections may lead to serious conditions, including septicemia or other invasive forms of the disease, which require rapid and accurate laboratory diagnosis and subsequently appropriate antimicrobial therapy. The aim of this study was to compare the species distribution and antimicrobial susceptibility pattern of Campylobacter spp. strains isolated from patients and food samples.

METHODS

Biochemical identification was performed on 15 clinical and 30 food isolates of Campylobacter recovered onto Brucella agar containing 5% sheep blood. PCR was carried out to confirm the identity of Campylobacter spp. using primers for cadF, hipO, and asp genes of Campylobacter. To determine antibiotic sensitivity of isolates, Kirby-Bauer assay was carried out using 16 different antibiotic discs.

RESULTS

PCR assay and biochemical tests confirmed all 45 isolates as Campylobacter: 20 (44.44%) as C. jujeni, 10 (22.22%) as C. coli, and 15 (33.34%) as other Campylobacter strains. The maximum resistance was observed to cefotaxime and imipenem (each 86.49%) and the maximum sensitivity to erythromycin (48.65%).

CONCLUSION

C. jujeni is dominant among isolates from clinical and food samples. In addition, tetracycline remains the first-line therapeutic agent against Campylobacter infections in Iran.

Campylobacter in Poultry: Ecology and Potential Interventions

Avian hosts constitute a natural reservoir for thermophilic Campylobacter species, primarily Campylobacter jejuni and Campylobacter coli, and poultry flocks are frequently colonized in the intestinal tract with high numbers of the organisms. Prevalence rates in poultry, especially in slaughter-age broiler flocks, could reach as high as 100% on some farms. Despite the extensive colonization, Campylobacter is essentially a commensal in birds, although limited evidence has implicated the organism as a poultry pathogen. Although Campylobacter is insignificant for poultry health, it is a leading cause of food-borne gastroenteritis in humans worldwide, and contaminated poultry meat is recognized as the main source for human exposure. Therefore, considerable research efforts have been devoted to the development of interventions to diminish Campylobacter contamination in poultry, with the intention to reduce the burden of food-borne illnesses. During the past decade, significant advance has been made in understanding Campylobacter in poultry. This review summarizes the current knowledge with an emphasis on ecology, antibiotic resistance, and potential pre- and postharvest interventions.

Campylobacter epidemiology from breeders to their progeny in Eastern Spain

While horizontal transmission is a route clearly linked to the spread of Campylobacter at the farm level, few studies support the transmission of Campylobacter spp. from breeder flocks to their offspring. Thus, the present study was carried out to investigate the possibility of vertical transmission. Breeders were monitored from the time of housing day-old chicks, then throughout the laying period (0 to 60 wk) and throughout their progeny (broiler fattening, 1 to 42 d) until slaughter. All samples were analyzed according with official method ISO 10272:2006. Results revealed that on breeder farms, Campylobacter isolation started from wk 16 and reached its peak at wk 26, with 57.0% and 93.2% of positive birds, respectively. After this point, the rate of positive birds decreased slightly to 86.0% at 60 wk. However, in broiler production all day-old chicks were found negative for Campylobacter spp, and the bacteria was first isolated at d 14 of age (5.0%), with a significant increase in detection during the fattening period with 62% of Campylobacter positive animals at the end of the production cycle. Moreover, non-positive sample was determined from environmental sources. These results could be explained because Campylobacter may be in a low concentration or in a non-culturable form, as there were several studies that successfully detected Campylobacter DNA, but failed to culture. This form can survive in the environment and infect successive flocks; consequently, further studies are needed to develop more modern, practical, cost-effective and suitable techniques for routine diagnosis.

Phenotypic and genotypic diversity of thermophilic Campylobacter spp. in commercial turkey flocks: a longitudinal study

Poultry are recognized as a main reservoir of Campylobacter spp. However, longitudinal studies investigating the persistence of Campylobacter on commercial meat turkeys are rare. The objectives of this study were to determine the prevalence, antimicrobial susceptibility, and persistence of genotypically related strains of Campylobacter spp. recovered from three commercial turkey farms in Ohio belonging to a single producer. Eight hundred ten samples were collected from birds aged 1 week to slaughter, consisting of 750 fecal droppings and 60 ceca at slaughter. Overall Campylobacter prevalence was 55.9%. Multiplex polymerase chain reaction (PCR) confirmed 72.3% of all isolates as C. coli, 5.3% as C. jejuni, 10.6% as both, and 11.9% as other Campylobacter spp. PCR restriction fragment length polymorphism of the flaA gene subtyping detected 70 types-62 for C. coli and 8 for C. jejuni isolates-with most (80%) of flaA-types constituting farm homogeneous groups. Multilocus sequence typing of 99 selected Campylobacter isolates resulted in 23 sequence types (STs), consisting of 8 STs for C. jejuni and 15 STs for C. coli isolates. Six novel STs-four for C. jejuni and two-for C. coli, were detected. In a subset of isolates (n=98) tested for antimicrobial resistance, the most common resistance was to tetracycline (95%), followed by azithromycin (43%), while 42% and 18% of the isolates were resistant to ciprofloxacin and erythromycin, respectively. All isolates were susceptible to florfenicol. C. coli isolates displayed a higher proportion of resistance than C. jejuni to most antimicrobials. This study highlights the high prevalence, genotypic diversity, and antimicrobial resistance of Campylobacter spp. in commercial turkey from farm to slaughter.

A systematic review characterizing on-farm sources of Campylobacter spp. for broiler chickens

Campylobacter and antimicrobial-resistant Campylobacter are frequently isolated from broiler chickens worldwide. In Canada, campylobacteriosis is the third leading cause of enteric disease and the regional emergence of ciprofloxacin-resistant Campylobacter in broiler chickens has raised a public health concern. This study aimed to identify, critically appraise, and synthesize literature on sources of Campylobacter in broilers at the farm level using systematic review methodology. Literature searches were conducted in January 2012 and included electronic searches in four bibliographic databases. Relevant studies in French or English (n = 95) conducted worldwide in any year and all study designs were included. Risk of Bias and GRADE criteria endorsed by the Cochrane collaboration was used to assess the internal validity of the study and overall confidence in the meta-analysis. The categories for on-farm sources were: broiler breeders/vertical transfer (number of studies = 32), animals (n = 57), humans (n = 26), environment (n = 54), and water (n = 63). Only three studies examined the antimicrobial resistance profiles of Campylobacter from these on-farm sources. Subgroups of data by source and outcome were analyzed using random effect meta-analysis. The highest risk for contaminating a new flock appears to be a contaminated barn environment due to insufficient cleaning and disinfection, insufficient downtime, and the presence of an adjacent broiler flock. Effective biosecurity enhancements from physical barriers to restricting human movement on the farm are recommended for consideration to enhance local on-farm food safety programs. Improved sampling procedures and standardized laboratory testing are needed for comparability across studies. Knowledge gaps that should be addressed include farm-level drug use and antimicrobial resistance information, further evaluation of the potential for vertical transfer, and improved genotyping methods to strengthen our understanding of Campylobacter epidemiology in broilers at the farm-level. This systematic review emphasizes the importance of improved industry-level and on-farm risk management strategies to reduce pre-harvest Campylobacter in broilers.

Comparison of Campylobacter jejuni pulsotypes isolated from humans and poultry in Split and Dalmatia County, Croatia

Consumption of poultry is considered to be an important source of human infection with Campylobacter. In the period from 2008 to 2010, 50 isolates of Campylobacter jejuni from human faeces were analysed and compared with 61 isolates from poultry by pulsed field gel electrophoresis using SmaI and KpnI. Based on the analysis of SmaI macrorestriction profiles, 86 isolates (77.5 %) were assigned to 15 S clusters: 31 (62 %) from humans and 55 from poultry (90.2 %). Altogether 21 isolates (19 %) exhibited macrorestriction profiles common to both humans and poultry after restriction with SmaI and KpnI. A total of five identical pulsotypes were isolated from both poultry and patients and one of them appeared in eight different locations in the time interval of one year. These results indicate that poultry could be an important source of Campylobacter infection in Split and Dalmatia County which is the biggest County in Croatia and the most important tourist destination.

Characterization of Campylobacter spp. transferred from naturally contaminated chicken legs to cooked chicken slices via a cutting board

Campylobacter represents the leading cause of gastroenteritis in Europe. Campylobacteriosis is mainly due to C. jejuni and C. coli. Poultry meat is the main source of contamination, and cross-contaminations in the consumer's kitchen appear to be the important route for exposure. The aim of this study was to examine the transfer of Campylobacter from naturally contaminated raw poultry products to a cooked chicken product via the cutting board and to determine the characteristics of the involved isolates. This study showed that transfer occurred in nearly 30% of the assays and that both the C. jejuni and C. coli species were able to transfer. Transfer seems to be linked to specific isolates: some were able to transfer during separate trials while others were not. No correlation was found between transfer and adhesion to inert surfaces, but more than 90% of the isolates presented moderate or high adhesion ability. All tested isolates had the ability to adhere and invade Caco-2 cells, but presented high variability between isolates. Our results highlighted the occurrence of Campylobacter cross-contamination via the cutting board in the kitchen. Moreover, they provided new interesting data to be considered in risk assessment studies.

Distribution and genotypic characterization of Campylobacter jejuni isolated from poultry in Split and Dalmatia County, Croatia

Consumption of poultry contaminated with Campylobacter jejuni has been recognized worldwide as the leading cause of campylobacteriosis. Therefore, the aim of our study was to investigate the prevalence and genotype diversity of Campylobacter jejuni in poultry meat intended for consumption in Split and Dalmatia County, which is the second biggest County in Croatia. Furthermore, we also wanted to discover possibly stable clones of C. jejuni appearing in different samples and periods of time, which would indicate their ability to persist in or adapt to poultry. In the period from March 2008 until June 2010, 834 samples of poultry from various sources were examined using a surface swab technique. Isolation of C. jejuni was performed by Preston broth and Karmali agar. Identification of the isolates was carried out using biochemical tests. C. jejuni was found in 84 of 574 chicken samples (14.6%) and in nine of 260 samples of turkey (3.5%). Pulse-field gel electrophoresis (PFGE) was used to analyse 61 obtained isolates using SmaI and KpnI. Of 22 different macrorestriction profiles (MRP) that were found, five were detected in poultry from both different locations and periods of time. Samples from 11 locations were found to be contaminated with more than two different genotypes of C. jejuni. Interestingly, the same MRP were found both in poultry declared to be of domestic origin and in the poultry imported from abroad. The prevalence of C. jejuni in poultry samples was in accordance with previously reported results. Genotypic analysis indicated that the population of C. jejuni in Split and Dalmatia County was diverse and that multiple strains of C. jejuni could be found in the same poultry samples. Furthermore, the same genotypes were identified from the samples obtained from different locations and periods of time, which could support the theory of a global existence of certain MRP that are able to persist in or adapt to poultry.

Biosecurity-based interventions and strategies to reduce Campylobacter spp. on poultry farms

The prevention and control of Campylobacter colonization of poultry flocks are important public health strategies for the control of human campylobacteriosis. A critical review of the literature on interventions to control Campylobacter in poultry on farms was undertaken using a systematic approach. Although the focus of the review was on aspects appropriate to the United Kingdom poultry industry, the research reviewed was gathered from worldwide literature. Multiple electronic databases were employed to search the literature, in any language, from 1980 to September 2008. A primary set of 4,316 references was identified and scanned, using specific agreed-upon criteria, to select relevant references related to biosecurity-based interventions. The final library comprised 173 references. Identification of the sources of Campylobacter in poultry flocks was required to inform the development of targeted interventions to disrupt transmission routes. The approach used generally involved risk factor-based surveys related to culture-positive or -negative flocks, usually combined with a structured questionnaire. In addition, some studies, either in combination or independently, undertook intervention trials. Many of these studies were compromised by poor design, sampling, and statistical analysis. The evidence for each potential source and route of transmission on the poultry farm was reviewed critically, and the options for intervention were considered. The review concluded that, in most instances, biosecurity on conventional broiler farms can be enhanced and this should contribute to the reduction of flock colonization. However, complementary, non-biosecurity-based approaches will also be required in the future to maximize the reduction of Campylobacter-positive flocks at the farm level.

Molecular tracking, through processing, of Campylobacter strains colonizing broiler flocks

Many of the poultry flocks produced in the United Kingdom are colonized with Campylobacter, and the intensive nature of poultry processing usually results in contaminated carcasses. In this study, a previously reported molecular oligonucleotide probe method was used to track a specific flock-colonizing strain(s) on broiler carcasses during processing in two United Kingdom commercial poultry processing plants. Five Campylobacter-positive flocks were sampled at four points along the processing line, postbleed, postpluck, prechill, and postchill, and two Campylobacter-negative flocks processed immediately after positive flocks were sampled prechill. flaA was sequenced from Campylobacter strains isolated from these flocks, and strain-specific probes were synthesized. Skin and cecal samples were plated onto selective agar to give individual colonies, which were transferred onto membranes. These were then hybridized with the strain- and genus-specific probes. For all the 5 positive flocks, there was a significant reduction in campylobacters postbleed compared to postpluck but no subsequent fall on sampling pre- and postchill, and the strain(s) predominating on the carcasses throughout processing came from the flock being processed. This indicates that strains from the abattoir environment were not a significant cause of carcass contamination in flocks with well-established campylobacter colonization. However, negative flocks that were preceded by positive flocks were contaminated by strains that did not generally originate from the predominating strains recovered from the ceca of the previous positive flocks. This suggests that the abattoir environment has a significant role in the contamination of carcasses from negative but not fully colonized flocks.

From farm to fork follow-up of thermotolerant campylobacters throughout the broiler production chain and in human cases in a Hungarian county during a ten-months period

A study tracking thermotolerant campylobacters from the setting of the broilers throughout the whole rearing period, slaughter and sale of chicken products in five consecutive broiler rotations of the same henhouse as well as in two different other farms was conducted in a well-defined geographic area (Hajdú-Bihar county, Hungary) between March 2006 and Feb 2007. All notified cases of human campylobacteriosis in this area during the study period were also included. One hundred and one, 44, 23 and 282 Campylobacter jejuni and 13, 15, 20 and 60C. coli were isolated from broiler houses, slaughterhouses, retail shops and human samples, respectively. Sixty-two isolates collected from broilers or their environment selected from different flocks (57C. jejuni, 5C. coli), 92 isolates collected from abattoirs and retail shops (72C. jejuni, 20C. coli), as well as 85 randomly selected human isolates (74C. jejuni, 11C. coli) were subjected to PFGE analysis using restriction enzymes KpnI and SmaI. Sixty-six of the isolates produced unique Sma-Kpn profiles; the majority (46) of these were of human origin. The remaining isolates formed PFGE clusters of between 2-25 isolates with 14 (12C. jejuni and 2C. coli) main clusters comprised of five or more isolates with identical KpnI-SmaI patterns. Two genetic clones of C. jejuni (clone A, n=25; clone B, n=20) included 18% of isolates from different sources. Generally, isolates from one cluster were found in 1-3 different flocks, notably, clone B was present in three rotations including those from the two independent farms. Six of the seven investigated flocks had one or two characteristic prevalent clones. Transmission of clones between consecutive flocks was frequently seen. Spread of both C. jejuni and C. coli was traced multiple times along the food chain; eight C. jejuni, but no C. coli clones were detected both in broilers and humans. These data suggest that broilers were the major source for C. jejuni but not for C. coli in the studied area and period. For C. jejuni the carryover of strains between consecutive flocks may be a common event, but the strain is eventually replaced by another and consecutive carryover events seem to be infrequent. The majority of the human disease was due to nonepidemic strains; some clones were transmitted from more than one broiler flocks (including epidemiologically unrelated flocks) to humans multiple times.

Campylobacter from sows in farrow-to-finish pig farms: risk indicators and genetic diversity

Sows have been identified as a source of Campylobacter contamination in piglets. We carried out a one-year study, in 2008, at 53 farrow-to-finish farms in Brittany, France, to determine the proportion of sows excreting Campylobacter. We also determined the genotypes of the Campylobacter isolates. Moreover, Generalized Estimating Equations including repeated effects were used to assess the association between management practices and farm characteristics, and risk of Campylobacter shedding by sows. Per farm, 10 feces samples from sows were collected from selected sites (maternity, service area, gestation area) on the farms. Campylobacter isolates were identified by PCR and typed by PFGE. Campylobacter was detected in 25.1% of the 530 samples from sows, and 67% of the 53 pig farms had at least one positive sample (of 10 taken). All the Campylobacter isolates belonged to the Campylobacter coli species. They displayed a very high level of genetic diversity, also inside farms and few genotypes were common to several farms. Warmer months, large farms, and individual housing for sows were identified as risk indicators of Campylobacter shedding by sows. A short delay between sampling and treatment of the samples should be considered, to improve the detection of the bacterium in the feces samples.

Influence of production system on the rate of onset of Campylobacter colonization in chicken flocks reared extensively in the United Kingdom

1. Because thermophilic Campylobacter spp. are common in chicken flocks reared extensively, cross-sectional and longitudinal studies were carried out on organic and free-range farms to determine the onset of colonisation (lag phase) and likely sources of flock infection. 2. For 14 organic and 14 free range flocks, there was a difference in lag phases, with the former being colonized at a mean of 14·1 d in comparison with 31·6 d for the latter. Whereas most free-range flocks became colonized when released on to pasture, those reared organically were usually colonized at the housed brooding stage. 3. Further study of organic flocks on three farms over 7 successive crop cycles confirmed that colonisation was strongly influenced by the prevailing husbandry conditions and was not a consequence of the length of the rearing period. 4. Molecular epidemiological investigations on a farm showing the shortest lag phase, using PFGE typing with two different restriction enzymes (SmaI and KpnI) and flaA SVR sequence typing, revealed that potential sources of colonisation for organic chickens were already present on the farm at the time of chick placement. Such sources included the ante area of the brooding house, surrounding pasture and other livestock being kept on the farm. 5. Overall, the study demonstrated that, under UK conditions, the prevalence of colonisation was greater in extensive flocks (95-100%) than it was for conventional broilers (55%), similar to the situation in other countries, but all three management systems showed comparable levels of caecal carriage in positive birds (log(10)/g 6·2-6·7).

Molecular characterization of Campylobacter spp. isolated from poultry faeces and carcasses in Poland

Campylobacterinfection is one of the most common enteric human diseases world-wide but the mechanism ofCampylobacterpathogenicity has not been exactly explained yet. One of the main reasons is genotypic, hence phenotypic diversity of the bacterial isolates. The aim of the present study was to perform a molecular characterization of randomly selectedC.jejuniandC. colistrains isolated from poultry faeces and carcasses in Poland. Several virulence gene markers were identified by polymerase chain reaction (PCR). Furthermore, genetic typing has also been used by the macrorestriction profiling with pulsed-field gel electrophoresis (PFGE). The results of the present study showed that all analyzed isolates ofC. jejuni(n = 24) andC. coli(n = 24) contained theflaAandcadFsequences. On the other hand, thevirB11gene was present only in 6 of 48 (12.5%) of the analyzed isolates, whereas most of the strains contained thecdtgenes. Other virulence geneiamlinked toCampylobacterinvasiveness was present in 34 of 48 (72.9%) strains. The restriction analysis of the whole genome digested withSmaI produced three main clonal groups designed as I, II (with two subgroups IIa and IIb), and III obtained by the comparison of macrorestriction profiling patterns. The results showed a poor correlation betweenCampylobacterprofiles generated by a clonal molecular technique and the presence of virulence markers. Therefore, PCR detection ofCampylobactervirulence markers can be utilized as a simple and rapid tool to discriminate stains recovered from different sources, especially when used in conjunction with the PFGE profile analysis as a complex strategy. These kinds of analyses had not been previously carried out in Poland and these results may generate more knowledge regarding the genetic diversity and molecular relationship ofCampylobacter.

A pulsed-field gel electrophoresis study of the genetic diversity of Campylobacter jejuni and Campylobacter coli in poultry flocks in Slovenia

Campylobacter jejuni and C. coli have recently become the most frequent cause of bacterial foodborne enteric infection in most industrialised countries. Consumption and handling of undercooked contaminated poultry meat was identified as an important risk factor for human campylobacteriosis. The aim of this study was to ascertain the genetic diversity of C. jejuni and C. coli strains isolated from poultry in Slovenia. A total of 68 isolates (42 C. jejuni , 26 C. coli ) from faeces (n = 48), meat (n = 15) and skin/carcasses (n = 5) of chicken (n = 60) and turkey samples (n = 5) were analysed by pulsed-field gel electrophoresis. Sma I macrorestriction discriminated between C. jejuni and C. coli isolates. C. jejuni isolates exhibited a higher degree of diversity compared to C. coli isolates. In the C. jejuni group, a number of small clusters were apparent, while C. coli strains formed less but larger clusters. Additional Kpn I digestion of selected isolates resulted in poor subtyping. Strains with identical or very similar profiles were found on different farms, either in the same or different regions and time periods. Some of the clones indicated possible cross-contamination at slaughterhouses.

Campylobacter species occurrence within internal organs and tissues of commercial caged Leghorn laying hens

Campylobacter spp. are frequently present in the intestinal tract and internal tissues of broiler breeder and broiler chickens. Campylobacter spp. ecology in commercial Leghorn laying hens has not been extensively studied. The objectives of the current study were to determine 1) Campylobacter spp. presence in the reproductive tract, lymphoid organs, liver-gallbladder, and ceca of commercial Leghorn laying hens; 2) species of Campylobacter present; and 3) antimicrobial resistance pattern of Campylobacter isolates. In study 1, three flocks ranging from 94 to 105 wk of age were sampled from a commercial laying complex. In study 2, two flocks, 82 and 84 wk of age, were sampled from a separate complex. Hens were killed, defeathered, aseptically necropsied, and the spleen, liver-gallbladder, ovarian follicles, and upper (infundibulum, magnum, and isthmus) and lower (shell gland and vagina) reproductive tracts were aseptically removed before the ceca. Samples were packed on ice and transported to the laboratory for evaluation. For speciation, a standard BAX real-time PCR method was used while susceptibility testing was performed using US National Antimicrobial Resistance Monitoring System (NARMS) standards and recommended quality control organisms. Isolates were examined for susceptibility using a semi-automated testing system (Sensititer) to the following 9 antimicrobials: azithromycin, clindamycin, ciprofloxacin, erythromycin, florfenicol, gentamicin, nalidixic acid, telithromycin, and tetracycline. In study 1, the isolation rate was 13, 67, 53, 3, 13, and 57% from the ovarian follicles, lower reproductive tract, upper reproductive tract, spleen, liver-gallbladder, and ceca, respectively. In study 2, the isolation rate was 17, 43, 33, 20, 17, and 73% from the ovarian follicles, lower reproductive tract, upper reproductive tract, spleen, liver-gallbladder, and ceca, respectively. Overall, 50% of isolates were Campylobacter jejuni, 49% Campylobacter coli, and 1% Campylobacter lari. In study 1, all of the isolates were pan-susceptible. In study 2, thirty-seven percent of the isolates were resistant to tetracycline. Commercial table egg laying hens housed in colony cages on wire floors had diverse Campylobacter spp. recovered from different tissues and these isolates were not resistant to a broad range of antimicrobials.

Description and sources of contamination by Campylobacter spp. of river water destined for human consumption in Brittany, France

Presence or absence of Campylobacter spp. in water of five rivers upstream from an intake point for drinking water production was investigated, and isolates genetically compared with human, pig and poultry isolates in order to determine their source. River water and drinking water obtained from these rivers were sampled one time per month, over a period of one year, and tested for Campylobacter. Isolates were typed by PFGE. Campylobacter was not detected in treated drinking water, but 50% of the river samples were contaminated. Contamination was observed on the four seasons. In total, 297 Campylobacter isolates were collected and generated 46 PFGE profiles. Campylobacter jejuni was the most frequently detected species in samples (74.1% of the isolates), followed by Campylobacter coli (17.8%) and Campylobacter lari (8.1%). Forty-two of the 46 PFGE profiles were unique. Only one genotype was detected three times in a river during the year and four genotypes in two different rivers. When compared to animal and human Campylobacter PFGE profiles, 14, 11 and one Campylobacter genotypes from water were genetically closed to human, poultry, and pig Campylobacter genotypes, respectively. The Campylobacter population displayed a high level of genetic diversity, suggesting that contamination originated from various origins. Human, poultry and pig were sources of contamination of the river by Campylobacter. Finally, no Campylobacter were detected in drinking water, indicating that the risk of outbreaks due to consumption of drinking water is low.

Quantification of thermotolerant Campylobacter in Swiss water treatment plants, by real-time quantitative polymerase chain reaction

A total of 49 wastewater samples from 23 different wastewater treatment plants (WWTPs) were analyzed using real-time quantitative polymerase chain reaction for the presence and quantity of thermotolerant campylobacters. Thermotolerant campylobacters were detected in 87.5% (21/24) and 64% (16/25) of untreated and treated wastewater samples, respectively. Their concentration was sufficiently high to be quantified in 20.4% (10/49) of the samples. In these samples, the concentration ranged from 68,000 to 2,292,000 cells/L in untreated wastewater and from 10,800 to 28,000 cells/L in treated water. We conclude that thermotolerant campylobacters present a health hazard for workers at WWTPs in Switzerland.