Prevalence and risk factors for Campylobacter spp. in chicken broiler flocks in Reunion Island (Indian Ocean)

Genomic characterization of molecular markers associated with antimicrobial resistance and virulence of the prevalent Campylobacter coli isolated from retail chicken meat in the United Arab Emirates

Campylobacter is a major cause of gastroenteritis worldwide, with broiler meat accounting for most illnesses. Antimicrobial intervention is recommended in severe cases of campylobacteriosis. The emergence of antimicrobial resistance (AMR) in Campylobacter is a concerning food safety challenge, and monitoring the trends of AMR is vital for a better risk assessment. This study aimed to characterize the phenotypic profiles and molecular markers of AMR and virulence in the prevalent Campylobacter species contaminating chilled chicken carcasses sampled from supermarkets in the United Arab Emirates (UAE). Campylobacter was detected in 90 (28.6%) out of 315 tested samples, and up to five isolates from each were confirmed using multiplex PCR. The species C. coli was detected in 83% (75/90) of the positive samples. Whole-genome sequencing was used to characterize the determinants of AMR and potential virulence genes in 45 non-redundant C. coli isolates. We identified nine resistance genes, including four associated with resistance to aminoglycoside (aph(3')-III, ant(6)-Ia, aph(2″)-Ib, and aac(6')-Im), and three associated with Beta-lactam resistance (blaOXA-61, blaOXA-193, and blaOXA-489), and two linked to tetracycline resistance (tet(O/32/O), and tet(O)), as well as point mutations in gyrA (fluoroquinolones resistance), 23S rRNA (macrolides resistance), and rpsL (streptomycin resistance) genes. A mutation in gyrA 2 p.T86I, conferring resistance to fluoroquinolones, was detected in 93% (42/45) of the isolates and showed a perfect match with the phenotype results. The simultaneous presence of blaOXA-61 and blaOXA-193 genes was identified in 86.6% (39/45) of the isolates. In silico analysis identified 7 to 11 virulence factors per each C. coli isolate. Some of these factors were prevalent in all examined strains and were associated with adherence (cadF, and jlpA), colonization and immune evasion (capsule biosynthesis and transport, lipooligosaccharide), and invasion (ciaB). This study provides the first published evidence from the UAE characterizing Campylobacter virulence, antimicrobial resistance genotype, and phenotype analysis from retail chicken. The prevalent C. coli in the UAE retail chicken carries multiple virulence genes and antimicrobial resistance markers and exhibits frequent phenotype resistance to macrolides, quinolones, and tetracyclines. The present investigation adds to the current knowledge on molecular epidemiology and AMR development in non-jejuni Campylobacter species in the Middle East and globally.

Quantification of Campylobacter contamination on chicken carcasses sold in retail markets in the United Arab Emirates

Background

Campylobacter is among the leading causes of foodborne zoonotic disease worldwide, with chicken meat accounting for the majority of human illnesses. This baseline study generates the first quantitative data for Campylobacter contamination in the United Arab Emirates chicken meat. Such data will help inform risk analysis and develop evidence-based food safety management.

Methods

For a year, chilled whole chicken carcasses (n = 315) belonging to seven different companies were collected from retail supermarkets. According to standard methods, Campylobacter enumeration was achieved by a direct plating in all chicken samples, and isolates were confirmed using multiplex PCR.

Results

Campylobacter spp. were recovered from 28.6% (90/315) of the samples. Campylobacter enumeration results indicated that 71.4% of the tested samples were contaminated with < 1 log10 CFU (colony-forming units)/g, and 7% were contaminated with ≥3 log10 CFU/g. The mean Campylobacter concentration was 2.70 log10 CFU/g, with a standard deviation of 0.41 log10 CFU/g. Campylobacter counts varied significantly in relation to the sourcing chicken processing companies. Six out of the seven surveyed companies provided Campylobacter positive samples. Moreover, significantly higher (p-value< 0.0001) counts were found to be associated with smaller size chicken carcasses (weighted 600–700 g; compared to the other categories, 800 g and 900–1000 g). Interestingly, C. coli was present in 83% of the positive samples, while C. jejuni was only detected in 6.4% of the samples. Compared with studies from other countries utilizing the same enumeration method, the UAE chicken appears to have a lower prevalence but a higher Campylobacter count per gram of carcasses. Higher Campylobacter counts were significantly associated with smaller carcasses, and C. coli was the dominant species detected in this study’s samples.

Conclusion

These results add to our understanding of the local, regional and global epidemiology of Campylobacter in chicken meat. Outputs of the current study may aid in developing a risk assessment of Campylobacter in the UAE, a country among the biggest per capita consumption markets for chicken meat worldwide.

Prevalence and antimicrobial resistance of Campylobacter jejuni and C. coli identified in a slaughterhouse in Argentina

The aim of this study was to evaluate the percentage of Campylobacter (C. jejuni and C. coli) from samples collected at the slaughterhouse to describe the prevalence of resistance to selected antimicrobials, and to characterize the genetic determinants. In total, from 333 samples analyzed, 31% were positive for Campylobacter. More positive samples were detected before the chiller (46%) than after the chiller (16%). C. coli (59%) was more prevalent than C. jejuni (41%). Antimicrobial resistance differences between C. jejuni and C. coli were found (p < 0.001). Multidrug resistance was found in 72% of C. coli isolates and 69% of C. jejuni isolates (p < 0.001). Most C. jejuni isolates (57%) had the three genes of the cmeABC efflux pump. The tet(O) gene and resistance-associated point mutations within both the gyrA and 23S rRNA genes were detected in 100% of C. coli isolates. On the other hand, C. jejuni only had more prevalence of the bla_OXA-61 gene than C. coli (p < 0.001), and most of the C. jejuni isolates (70–80%) had the tet(O) and gyrA point mutation. These results could contribute to knowledge about the status of thermotolerant Campylobacter resistant to antimicrobials isolated from food animals in Argentina and to develop an antimicrobial resistance surveillance system.

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From samples analyzed, 31% were positive for Campylobacter.

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More positive samples were detected before the chiller (46%) than after it (16%).

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Multidrug resistance was found in 72% of C. coli isolates and 69% of C. jejuni isolates.

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The tet(O) gene was detected in 100% of the tetracycline-, resistantC. coliisolates.

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C.jejuni only had more prevalence of the bla_OXA-61 gene than C. coli (p < 0.001).

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

Simple Summary

Investigation of Campylobacter prevalence throughout the entire chicken production process from farms to retail meat is still limited. In this study, we examined the prevalence and antimicrobial susceptibility of Campylobacter in 10 production lines from one of the largest integrated poultry production companies in Korea. The prevalence of Campylobacter in breeder farm, hatchery, broiler farm, slaughterhouse, and retail meat products was 50.0%, 0%, 3.3%, 13.4%, and 68.4%, respectively. Resistance to fluoroquinolones was the most frequently observed, and 16 isolates from breeder farm were resistant to both azithromycin and ciprofloxacin. Diverse pulsed-field gel electrophoresis 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.

Abstract

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.

Review of Quantitative Microbial Risk Assessment in Poultry Meat: The Central Position of Consumer Behavior

Food of animal origin, especially meat products, represent the main vehicle of foodborne pathogens and so are implicated in foodborne outbreaks. Poultry meat is a widely consumed food in various forms, but it is also a reservoir of thermotolerant Campylobacter and Salmonella bacterial species. To assess human health risks associated with pathogenic bacteria in poultry meat, the use of quantitative microbial risk assessment (QMRA) has increased over the years as it is recognized to address complex food safety issues and is recommended by health authorities. The present project reviewed poultry meat QMRA, identified key steps of the farm-to-fork chain with significant impacts on food safety, highlighted current knowledge gaps, and provided risk mitigation advices. A PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)-based systematic analysis was carried out and enabled the collection of 4056 studies including 42 QMRA kept for analysis after screening. The latter emphasized Campylobacter spp. and Salmonella spp. contaminations during the consumer stage as the main concern. The role of consumer handling on cross-contamination and undercooking events were of major concern. Thus, proper hygiene and safety practices by consumers have been suggested as the main intervention and would need to be followed with regular surveys to assess behavior changes and reduce knowledge gaps.

Prevalence and risk factors of Campylobacter infection in broiler and cockerel flocks in Mymensingh and Gazipur districts of Bangladesh

Campylobacter spp. is one of the most frequent causes of foodborne gastroenteritis. This study aimed to estimate the prevalence and to identify the risk factors of farm-level Campylobacter infection in meat-type chicken flocks. A cross-sectional study was conducted in two selected districts of Bangladesh over the period of January to July 2019. A total of 84 pooled cloacal swab samples were collected from 84 broiler and cockerel farms. Data on farm management, biosecurity, and hygiene practices were collected using a structured questionnaire through a face-to-face interview during sampling. Thereafter, Campylobacter spp. were isolated through bacteriological culture and identified by Gram staining and biochemical tests. Furthermore, the isolates were confirmed using the polymerase chain reaction by targeting the 16S rRNA gene. The risk factors were analyzed at the farm level using multivariable logistic regression with the significant levels of P-value ≤ 0.05. Among the 84 farms, 34 were positive to Campylobacter spp.; thus, the prevalence was estimated to be 40.5% (95% CI: 30.1%-51.8%). In risk factor analysis, the following factors were found to be significantly associated with Campylobacter infection: shed older than five years, birds older than 30 days, flock size with more than 1500 birds, downtime less than seven days, no disinfection of shed surroundings during rearing, rice husk as litter materials, and less than 10 years of farming experience. The study identified the factors that could lead to the setting of effective interventions in controlling Campylobacter infection in chickens to reduce campylobacteriosis in humans through meat consumption.

Prevalence, genotypic diversity and detection of virulence genes in thermotolerant Campylobacter at different stages of the poultry meat supply chain

Thermotolerant Campylobacter is the leading bacterial cause of foodborne illness in humans worldwide. The objectives of this study were to estimate prevalence and to identify and characterize potential sources of thermotolerant Campylobacter contamination in broilers on farms and at the slaughterhouse; to evaluate the clonal relationship among thermotolerant Campylobacter isolates from different stages of the broiler meat supply chain, and to analyze the presence of virulence genes in different sources of thermotolerant Campylobacter. A total of 1210 samples were collected from three broiler meat supply chains in Santa Fe, Argentina. At the farms, the sampling collection included broilers one week prior to slaughter, wild-living birds, domestic dogs, wild rodents, farm workers' boots, litter, feed, drinking water, flies, and darkling beetles (Alphitobius diaperinus). At the slaughtering line, the samples taken were from the evisceration zone (broiler cecum, working surfaces, evisceration knives and workers' hands), from the chiller zone (surfaces and direct supply water) and from the packing zone (work surfaces, workers' hands and broiler carcasses). The samples taken along each supply chain were in the same batch. The isolates obtained were identified to the species level (C. jejuni and C. coli) by multiplex PCR and were analyzed using pulsed-field gel electrophoresis to compare different profiles according to the source. Finally, the presence of 11 virulence genes was examined (cadF, cdtA, cdtB, cdtC, ciaB, flaA, flhA, iam, wlaN, virB11, racR). From 254 isolates, 128 (50.4%) were Campylobacter jejuni and 126 (49.6%) Campylobacter coli. C. jejuni was the species most prevalent in farm and C. coli the species most prevalent at the slaughterhouse. We detected thermotolerant Campylobacter in samples of wild birds, darkling beetles, farm workers' boots, flies and litter. At the slaughterhouse, the prevalence varied along the process line. By analyzing PFGE results, C. jejuni showed 21 profiles with three predominant genotypes, while C. coli showed 14 profiles with four predominant genotypes. A high genotype diversity was found; however, relationships between isolates from different stages of the broiler meat chain, between broiler and potential sources of thermotolerant Campylobacter contamination and between strains in the farm and in the slaughterhouse were detected. Furthermore, there was evidence of cross-contamination at the slaughterhouse. FlaA, flhA genes were detected in all strains, and the third most prevalent virulence gene was cadF. Only those strains obtained from flies, wild-living birds and broiler carcass samples harbored 10 of 11 pathogenic genes. The prevalence of some pathogenic genes between C. jejuni and C. coli was different. This evidence should contribute the scientific basis to implement risk management measures in public health.

Epidemiology and antimicrobial resistance of Campylobacter spp. in animals in Sub-Saharan Africa: A systematic review

Introduction

Low sanitary conditions characterize the rural and urban households in Sub-Saharan African region. Those environmental conditions propitiate the transmission of bacterial infections between animals and humans. Campylobacter spp. is a zoonotic bacterium and cause of human gastroenteritis worldwide, whose main symptom is diarrhea. It is normally found in the digestive tract of many farm animals as a commensal but some species cause diseases in animals. It is important to understand the occurrence of these bacteria in animals, as they may also play a role in transmission to humans. The main objective of this review was to describe the prevalence of Campylobacter in animals in Sub-Saharan Africa. We also report findings on antibiotic resistance.

Methods

We followed PRISMA guidelines to find studies about occurrence of Campylobacter spp. in animals in all countries from Sub-Saharan Africa. PubMed, Cochrane Library, CINAHL, African Index Medicus, African Journals Online, Google Scholar and Science Direct were searched for studies published between 2000 and 2019.

Results

We found 70 studies that described occurrence of Campylobacter spp. in animals in 18 out of 53 countries of Sub-Saharan Africa. Campylobacter jejuni and C. coli were the predominant species isolated. The majority of studies were found in Western Africa. Middle Africa had the lowest amount of data. Most records presented data from Nigeria (n = 25), South Africa (n = 14) and Tanzania (n = 11). Cattle and chickens appear to be important hosts and may be playing an important role in transmitting to humans. Most Campylobacter isolates were resistant to erythromycin (44%), ampicillin (39%), tetracycline (33%), nalidixic acid (31%) and ciprofloxacin (30%).

Conclusion

Several studies about Campylobacter spp. in animals have been published in the last 19 years but information on the epidemiology of campylobacteriosis is scarce in most Sub-Saharan African countries. Antibiotic resistance is an increasing concern in many countries. Measures should be taken to prevent infection by this pathogen in the region and to control antibiotic resistance.

Impacts of small-scale chicken farming activity on antimicrobial-resistant Escherichia coli carriage in backyard chickens and children in rural Ecuador

The emergence, spread, and persistence of antimicrobial resistance (AMR) remains a pressing global concern. Increased promotion of commercial small-scale agriculture within low-resource settings has facilitated an increased use in antimicrobials as growth promoters globally, creating antimicrobial-resistant animal reservoirs. We conducted a longitudinal field study in rural Ecuador to monitor the AMR of Escherichia coli populations from backyard chickens and children at three sample periods with approximately 2-month intervals (February, April, and June 2017). We assessed AMR to 12 antibiotics using generalized linear mixed effects models (GLMM). We also sampled and assessed AMR to the same 12 antibiotics in one-day-old broiler chickens purchased from local venders. One-day-old broiler chickens showed lower AMR at sample period 1 compared to sample period 2 (for 9 of the 12 antibiotics tested); increases in AMR between sample periods 2 and 3 were minimal. Two months prior to the first sample period (December 2016) there was no broiler farming activity due to a regional collapse followed by a peak in annual farming in February 2017. Between sample periods 1 and 2, we observed significant increases in AMR to 6 of the 12 antibiotics in children and to 4 of the 12 antibiotics in backyard chickens. These findings suggest that the recent increase in farming, and the observed increase of AMR in the one-day old broilers, may have caused the increase in AMR in backyard chickens and children. Small-scale farming dynamics could play an important role in the spread of AMR in low- and middle-income countries.

The Prevalence of Campylobacter spp. in Polish Poultry Meat

The prevalence, count and molecular identification of Campylobacter spp. in Polish poultry meat were analysed. 181 samples of meat from chicken (70), turkey (47), duck (54) and goose (10) were studied. Campylobacter spp. was found in 64% of meat samples. The highest prevalence of this pathogen was detected for duck meat. On average 80% of duck samples were contaminated with Campylobacter spp. The counts of Campylobacter spp. in positive samples remained under ten colony forming units per gram of product in 59% of poultry meat. C. jejuni was more frequently detected in poultry meat than C. coli.

Prevalence and risk factors for thermotolerant species of Campylobacter in poultry meat at retail in Europe

The thermotolerant species Campylobacter jejuni, Campylobacter coli, Campylobacter lari and Campylobacter upsaliensis are the causative agents of the human illness called campylobacteriosis. This infection represents a threat for the health of consumers in Europe. It is well known that poultry meat is an important food vehicle of Campylobacter infection. As emerged from the reported scientific literature published between 2006 and 2016, poultry meat sold at retail level in Europe represents an important source of the pathogen. The contamination level of poultry meat sold at retail can vary depending on pre- and post-harvest factors. Among the pre-harvest measures, strict biosecurity practices must be guaranteed; moreover, among post-harvest control measures scalding, chilling and removal of faecal residues can reduce the contamination level of Campylobacter. An additional issue is represented by increasing proportion of Campylobacter isolates resistant to tetracyclines, ciprofloxacin, and nalidixic acid, thus feeding a serious concern on the effectiveness of antibiotic treatment for human campylobacteriosis in a near future.

Campylobacter in Broiler Chicken and Broiler Meat in Sri Lanka: Influence of Semi-Automated vs. Wet Market Processing on Campylobacter Contamination of Broiler Neck Skin Samples

Broiler meat can become contaminated with Campylobacter of intestinal origin during processing. The present study aimed to identify the prevalence of Campylobacter in broiler flocks and meat contamination at retail shops, and determine the influence of semi-automated and wet market processing on Campylobacter contamination of neck skin samples. Samples were collected from semi-automated plants (n = 102) and wet markets (n = 25). From each batch of broilers, pooled caecal samples and neck skin samples were tested for Campylobacter. Broiler meat purchased from retail outlets (n = 37) was also tested. The prevalence of Campylobacter colonized broiler flocks was 67%. The contamination of meat at retail was 59%. Both semi-automated and wet market processing resulted to contaminate the broiler neck skins to the levels of 27.4% and 48%, respectively. When Campylobacter-free broiler flocks were processed in semi-automated facilities 15% (5/33) of neck skin samples became contaminated by the end of processing whereas 25% (2/8) became contaminated after wet market processing. Characterization of isolates revealed a higher proportion of C. coli compared to C. jejuni. Higher proportions of isolates were resistant to important antimicrobials. This study shows the importance of Campylobacter in poultry industry in Sri Lanka and the need for controlling antimicrobial resistance.

Antimicrobial Resistance of Campylobacter Species Isolated from Broilers in Live Bird Markets in Shanghai, China

This study was conducted to determine the prevalence of antimicrobial resistance in Campylobacter spp. isolates from broilers in live bird markets (LBMs). A total of 209 Campylobacter spp. isolates (84 Campylobacter jejuni; 125 Campylobacter coli) were recovered from 364 broiler cecum samples collected from five LBMs in Shanghai, China. Minimum inhibitory concentrations of 13 antimicrobials were determined using agar dilution method. More than 96% of the Campylobacter spp. isolates were resistant to quinolones and tetracyclines. A high prevalence of macrolide resistance (erythromycin, 84.0%; azithromycin, 80.8%) was observed in C. coli, but not in C. jejuni (erythromycin, 6.0%; azithromycin, 2.4%). C. coli also showed significantly higher resistance than C. jejuni to clindamycin, gentamicin, and kanamycin. In contrast, C. coli isolates had lower resistance to florfenicol than the C. jejuni isolates. The majority of the C. jejuni (88.1%) and C. coli (97.6%) isolates exhibited multidrug resistance (MDR) to three or more classes of antimicrobials. All of the 208 ciprofloxacin-resistant Campylobacter spp. isolates were positive for the C257T mutation of the gyrA gene. In addition, the tet(O) gene was identified in all of the 202 doxycycline-resistant Campylobacter spp. isolates. Furthermore, 75.7% and 20.4% of the 103 azithromycin-resistant Campylobacter spp. isolates were positive for the A2075G mutation of the 23S rRNA gene and the presence of the erm(B) gene, respectively. Moreover, the cat gene was found in 14.3% (8/56) and 76.8% (73/95) of the chloramphenicol-resistant C. jejuni and C. coli isolates, respectively. To the best of our knowledge, this is the first report of the prevalence of antimicrobial resistance among Campylobacter spp. isolates originating from LBMs. The high prevalence of MDR Campylobacter spp. isolates in LBMs highlights the need to implement efficient intervention measures to control not only Campylobacter contamination in LBMs but also dissemination of antimicrobial resistance among Campylobacter spp. in poultry production.

Estimating sensitivity and specificity of a PCR for boot socks to detect Campylobacter in broiler primary production using Bayesian latent class analysis

The present study compares three different assays for sample collection and detection of Campylobacter spp. in broiler flocks, based on (i) the collection of faecal samples from intestinal organs (caecum), (ii) individual faecal droppings collected from the bedding and (iii) faecal material collected by socks placed on the outside of a pair of boots (boot socks) and used for walking around in the flock. The two first methods are examined for Campylobacter using a culture method (ISO-10272-2:2006), while the boot socks are tested using PCR. The PCR-assay is a genus specific multiplex PCR with primers targeting 16S rDNA in Campylobacter and primers targeting Yersinia ruckerii. Sixty-seven broiler flocks from Austria and 83 broiler flocks from Denmark were included in this prospective study and 89 of these were found to be positive in at least one method (AT: 49 samples, DK: 40 samples) whereas 61 of these were negative in all assays. In Austria samples for the three assays were collected simultaneously, which facilitates a direct comparison of the diagnostic test performance. In Denmark, however, boot socks and faecal droppings were collected three days before slaughter while caecum samples were collected at slaughter. The results were evaluated in the absence of a gold standard using a Bayesian latent class model. Austrian results showed higher sensitivity for PCR detection in sock samples (0.98; Bayesian credible interval (BCI) [0.93-1]) than for culture of faecal droppings (0.86; BCI [0.76-0.91]) or caecal samples (0.92; BCI [0.85-0.97]). The potential impact of Campylobacter introduction within the final three days before slaughter was observed in Denmark, where four flocks were tested negative three days before slaughter, but were detected positive at the slaughterhouse. Therefore the model results for the PCR sensitivity (0.88; BCI [0.83-0.97]) and cultural ISO-method in faecal samples (0.84; BCI [0.76-0.92]) are lower than for caecal samples (0.93; BCI [0.85-0.98]). In our study, PCR detection on boot sock samples is more sensitive than conventional culture. In view of the advantage of rapid results before slaughter and low costs for sampling, especially in combination with existing Salmonella surveillance systems (just another pair of boot socks needed), this method-matrix combination could be a valuable surveillance tool in the broiler primary production.

Tracking Campylobacter contamination along a broiler chicken production chain from the farm level to retail in China

This study was conducted to determine the prevalence and distribution of Campylobacter species along a broiler production chain from farm to retail, and to evaluate the antimicrobial resistance profile of Campylobacter isolates. A total of 259 Campylobacter isolates (C. jejuni n=106, C. coli n=153) were isolated from broiler ceca samples (72.5%, 103/142), broiler carcasses (34.1%, 46/135), and retail broiler meat (31.3%, 40/128) samples collected in Shanghai, China. Minimal inhibitory concentrations of six antimicrobials were determined using the agar dilution method. High prevalence of resistance to ciprofloxacin (C. jejuni: 99.1%;C. coli: 100%) and tetracycline (C. jejuni: 100%;C. coli: 98.7%) was detected among the C. jejuni and C. coli isolates. The vast majority of C. coli were resistant to clindamycin (92.2%), gentamicin (95.4%), and erythromycin (94.1%), but only 25.5%, 53.8%, and 16.0% of C. jejuni exhibited resistance to these three antimicrobials, respectively. In contrast, the prevalence of florfenicol resistance in C. jejuni (37.7%) was significantly higher than that in C. coli (7.8%) (P<0.05). It is noteworthy that all Campylobacter isolates were resistant to one or more antimicrobials, and 71.7% of C. jejuni and 98.0% of C. coli isolates exhibited multi-drug resistance (resistant to three or more antimicrobials). Fifty-five C. jejuni and sixty C. coli isolates, selected from different production stages, species, and antimicrobial resistance patterns, were analyzed by pulsed field gel electrophoresis (PFGE), among which 15 unique PFGE patterns (PFGE patterns represented by a single strain) and 31 clusters (PFGE patterns represented by multiple strains) were detected. Furthermore, nearly all of the PFGE patterns of the Campylobacter strains isolated from retail broiler meats overlapped with those of the strains from ceca and slaughterhouse carcasses. Together, these findings revealed the high prevalence of Campylobacter species in a broiler chicken production chain, and the concerning situation of antimicrobial resistance in Campylobacter species. The findings also indicated that Campylobacter isolates from retail broiler meats were associated with fecal contamination in the slaughterhouse, underlying the need for improved measures for reducing carcass contamination in slaughter plants.

An epidemiological investigation of Campylobacter in pig and poultry farms in the Mekong delta of Vietnam

Campylobacter are zoonotic pathogens commonly associated with gastroenteritis. To assess the relevance of Campylobacter in Vietnam, an economically transitioning country in SE Asia, we conducted a survey of 343 pig and poultry farms in the Mekong delta, a region characterized by mixed species farming with limited biosecurity. The animal-level prevalence of Campylobacter was 31·9%, 23·9% and 53·7% for chickens, ducks and pigs, respectively. C. jejuni was predominant in all three host species, with the highest prevalence in pigs in high-density production areas. Campylobacter isolates demonstrated high levels of antimicrobial resistance (21% and 100% resistance against ciprofloxacin and erythromycin, respectively). Multilocus sequence type genotyping showed a high level of genetic diversity within C. jejuni, and predicted C. coli inter-species transmission. We suggest that on-going intensification of animal production systems, limited biosecurity, and increased urbanization in Vietnam is likely to result in Campylobacter becoming an increasingly significant cause of human diarrhoeal infections in coming years.