A Baseline Quantitative Survey of Campylobacter spp. on Retail Chicken Portions and Carcasses in Metropolitan Perth, Western Australia

Campylobacter spp. in chicken meat from traditional markets in Peru and its impact measured through a quantitative microbiological risk assessment

Campylobacter is a major cause of foodborne gastroenteritis worldwide, with the mishandling of contaminated chicken meat among the main pathways for human infection. Granted the disease burden due to this pathogen, systematic assessments of its potential impact are necessary. The aims of this study were to evaluate both presence and load of Campylobacter in chicken meat sold in traditional markets, assess risk factors related with the infrastructure and hygienic conditions of market stalls, and evaluate control strategies for campylobacteriosis in Peru through a quantitative microbiological risk assessment (QMRA), a data-driven, systematic approach to quantitatively assess risks by integrating empirical contamination levels, microbial behavior, and consumer exposure. Between February and December 2022, a total of 90 chicken meat samples from traditional markets were sampled and evaluated by both culture and quantitative real-time polymerase chain reaction (qPCR). Campylobacter spp. were detected in 28 % and 76 % of samples with a mean quantification of 3.3 log10 CFU/g and 4.9 log10 GC/g through culture and qPCR, respectively. Market stalls with tap water showed higher prevalence and loads, while those without refrigeration had higher quantifications. The QMRA analysis, using the most conservative parameters and bacterial load, indicated that the entire modeled population develops campylobacteriosis at least once annually. These results highlight the public health impact of Campylobacter, potentially linked to the alarming number of Guillain-Barré syndrome cases observed in Peru. Our study suggests that consumer-level interventions, such as reducing kitchen cross-contamination and improving chicken meat storage, could substantially reduce campylobacteriosis cases in this population.

High prevalence and genomic features of multidrug-resistant Salmonella enterica isolated from chilled broiler chicken on retail sale in the United Arab Emirates

Non-typhoidal Salmonella represents a significant global concern for food safety and One Health. Despite the United Arab Emirates (UAE) being a leading consumer of chicken meat globally, there is a lack of comprehensive understanding regarding the prevalence and genomic characteristics of Salmonella within the country. This study aims to address this gap by conducting a thorough analysis of Salmonella prevalence, antimicrobial resistance, and genomic profiles of isolates obtained from whole broiler carcasses retailed under chilled conditions in the UAE. Our findings reveal that Salmonella was detected in 41.2 % (130/315) of the sampled chilled broiler carcasses, with notable variability observed among samples sourced from six different companies. Phenotypic antimicrobial resistance (AMR) testing, among 105 isolates, highlighted high resistance rates to tetracycline (97.1 %), nalidixic acid (93.3 %), ampicillin (92.4 %), azithromycin (75.2 %), ciprofloxacin (63.8 %), and ceftriaxone (54.3 %). Furthermore, a concerning 99 % (104/105) of the isolates exhibited multidrug resistance. Whole-genome sequencing (WGS) of 60 isolates identified five serovars, with S. infantis/Sequence Type (ST) 32 (55 %) and S. Minnesota/ST-458 (28.3 %) being the most prevalent. WGS analysis unveiled 34 genes associated with antimicrobial resistance, including mcr-1.1 (only in two isolates), conferring resistance to colistin. The two major serovars, Infantis and Minnesota, exhibited significant variation (P-values <0.001) in the distribution of major AMR genes (aadA1, blaCMY-2, blaSHV-12, qnrB19, qnrS1, sul1, and sul2). Notably, the gene qacEdelta, conferring resistance to quaternary ammonium compounds commonly found in disinfectants, was universally present in all S. Infantis isolates (n = 33), compared to only one S. Minnesota isolate. Additionally, all S. Infantis isolates harbored the IncFIB (pN55391) plasmid replicon type. Major serovars exhibited distinct distributions of antimicrobial resistance genes, underscoring the importance of serovar-specific surveillance. These findings emphasize the critical need for continuous surveillance and intervention measures to address Salmonella contamination risks in poultry products, providing valuable insights for public health and regulatory strategies not only in the UAE but also globally.

Quantitative assessment and genomic profiling of Campylobacter dynamics in poultry processing: a case study in the United Arab Emirates integrated abattoir system

In the United Arab Emirates, no previous research has investigated the dynamics of the foodborne pathogen Campylobacter in broiler abattoir processing. This study conducted in one of the largest poultry producers in the UAE, following each key slaughter stage-defeathering, evisceration, and final chilling-five broiler carcasses were collected from 10 slaughter batches over a year. Additionally, one caecum was obtained from 15 chickens in each slaughter batch to evaluate the flock colonization. In total, 300 samples (150 carcasses and 150 caeca) were collected and enumerated for Campylobacter using standard methods. Campylobacter was pervasive in caecal samples from all slaughter batches, with 86% of carcasses post-defeathering and evisceration stages and 94% post-chilling tested positive for Campylobacter. Campylobacter coli predominates in 55.2% of positive samples, followed by Campylobacter jejuni in 21%, with both species co-existing in 23.8% of the samples. Campylobacter counts in caecal contents ranged from 6.7 to 8.5 log10 CFU/g, decreasing post-defeathering and evisceration to 3.5 log10 CFU/g of neck skin and further to 3.2 log10 CFU/g of neck skin post-evisceration. After chilling, 70% of carcasses exceeded 3 log10 CFU/g of neck skin. Whole-genome sequencing (WGS) of 48 isolates unveiled diverse sequence types and clusters, with isolates sharing the same clusters (less than 20 single nucleotide polymorphisms) between different farms, different flocks within the same farm, as well as in consecutive slaughter batches, indicating cross-contamination. Multiple antimicrobial resistance genes and mutations in gyrA T86I (conferring fluoroquinolone resistance) and an RNA mutation (23S r.2075; conferring macrolide resistance) were widespread, with variations between C. coli and C. jejuni. WGS results revealed that selected virulence genes (pglG, pseD, pseI, flaA, flaB, cdtA, and cdtC) were significantly present in C. jejuni compared to C. coli isolates. This study offers the first insights into Campylobacter dynamics in poultry processing in the UAE. This work provides a base for future research to explore additional contributors to Campylobacter contamination in primary production. In conclusion, effective Campylobacter management demands a comprehensive approach addressing potential contamination sources at every production and processing stage, guided by continued microbiological surveillance and genomic analysis to safeguard public health and food safety.

Comparison of peroxyacetic acid and acidified sodium chlorite at reducing natural microbial contamination on chicken meat pieces

The spin-chill process at poultry processing plants involves the immersion of chicken carcasses in cold water (<5°C) often containing sodium hypochlorite which significantly contributes to the reduction of bacterial loads. Cutting carcasses into pieces, however, has been linked with increases in Campylobacter and Salmonella counts. Here, the efficacy of PAA and ASC on reducing bacteria on skin-on, bone-in thigh cuts was investigated. Three concentrations of ASC (60, 112, and 225 ppm) and PAA (50, 75, 100 ppm) were used. Thighs were dipped into sanitizer and tested for total viable bacterial counts, Campylobacter load, and prevalence of Salmonella. The efficacy of PAA and ASC was also compared with chlorine (8 ppm). All sanitizers exhibited a greater log reduction compared with water. PAA at both 75 and 100 ppm resulted in significantly higher log reductions compared with the water only. PAA at 100 ppm and 225 ppm ASC were the most effective at reducing Campylobacter. All wash treatments reduced the proportion of Salmonella positive samples, but the greatest reduction was observed for 225 ppm ASC. Both concentrations of ASC resulted in a greater reduction in total viable counts compared with chlorine.

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.

Quantitative detection and genetic characterization of thermotolerant Campylobacter spp. in fresh chicken meats at retail in Japan

Campylobacter jejuni and C. coli are one of the leading causes of gastrointestinal illnesses, and which are considered to be transmitted to humans mainly from chicken meats. Considering the less availability of quantitative contamination data in the retail chicken meats in Japan, 510 fresh chicken meats retailed at five distinct regions in Japan between June 2019 and March 2021 were examined. The quantitative testing resulted that 45.7% of the samples (254/510) were positive at mean ± standard deviation of 1.15 ± 1.03 logCFU/g, whereas 43 samples (8.4%) exceeded 3.0 logCFU/g. Seasonal comparison revealed increased bacterial counts in fall compared with spring and summer. As for the chicken slaughter age, those slaughtered at >75 days old were less contaminated than those at <75 days old. Genome sequencing analyses of 111 representative C. jejuni isolates resulted in the detection of three antimicrobial resistance genes (gyrA substitution T86I, tetO and blaOXA-61) at 25.2, 27.9 and 42.3%, respectively. In silico MLST analysis revealed the predominance of sequence types (ST)-21 clonal complex (CC), followed by ST-45CC and ST-464CC. The single nucleotide polymorphism (SNP)-based phylogenetic tree largely classified the sequenced C. jejuni isolates into two clusters (I and II), where all C. jejuni from highly contaminated samples (STs-21CC, -22CC and -45CC) belonged to cluster I, independent of both season and slaughter age. To our knowledge, this is the first example to study the current status of Campylobacter contamination levels in fresh chicken meats retailed in Japan. Our data would be contributable to future quantitative microbial risk assessment, to establish effective control measures for campylobacteriosis.

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.

Salmonella Prevalence Alone Is Not a Good Indicator of Poultry Food Safety

Salmonella is a leading cause of foodborne illness (i.e., salmonellosis) outbreaks, which on occasion are attributed to ground turkey. The poultry industry uses Salmonella prevalence as an indicator of food safety. However, Salmonella prevalence is only one of several factors that determine risk of salmonellosis. Consequently, a model for predicting risk of salmonellosis from individual lots of ground turkey as a function of Salmonella prevalence and other risk factors was developed. Data for Salmonella contamination (prevalence, number, and serotype) of ground turkey were collected at meal preparation. Scenario analysis was used to evaluate effects of model variables on risk of salmonellosis. Epidemiological data were used to simulate Salmonella serotype virulence in a dose-response model that was based on human outbreak and feeding trial data. Salmonella prevalence was 26% (n = 100) per 25 g of ground turkey, whereas Salmonella number ranged from 0 to 1.603 with a median of 0.185 log per 25 g. Risk of salmonellosis (total arbitrary units (AU) per lot) was affected (p ≤ 0.05) by Salmonella prevalence, number, and virulence, by incidence and extent of undercooking, and by food consumption behavior and host resistance but was not (p > 0.05) affected by serving size, serving size distribution, or total bacterial load of ground turkey when all other risk factors were held constant. When other risk factors were not held constant, Salmonella prevalence was not correlated (r = -0.39; p = 0.21) with risk of salmonellosis. Thus, Salmonella prevalence alone was not a good indicator of poultry food safety because other factors were found to alter risk of salmonellosis. In conclusion, a more holistic approach to poultry food safety, such as the process risk model developed in the present study, is needed to better protect public health from foodborne pathogens like Salmonella.

Human campylobacteriosis related to cross-contamination during handling of raw chicken meat: Application of quantitative risk assessment to guide intervention scenarios analysis in the Australian context

Quantitative Microbiological Risk Assessment (QMRA) is a methodology used to organize and analyze scientific information to both estimate the probability and severity of an adverse event as well as prioritize efforts to reduce the risk of foodborne pathogens. No QMRA efforts have been applied to Campylobacter in the Australian chicken meat sector. Hence, we present a QMRA model of human campylobacteriosis related to the occurrence of cross-contamination while handling raw chicken meat in Western Australia (WA). This work fills a gap in Campylobacter risk characterization in Australia and enables benchmarking against risk assessments undertaken in other countries. The model predicted the average probability of the occurrence of illness per serving of salad that became cross-contaminated from being handled following the handling of fresh chicken meat as 7.0 × 10^-4 (90% Confidence Interval [CI] ± 4.7 × 10^-5). The risk assessment model was utilized to estimate the likely impact of intervention scenarios on the predicted probability of illness (campylobacteriosis) per serving. Predicted relative risk reductions following changes in the retail prevalence of Campylobacter were proportional to the percentage desired in the reduction scenario; a target that is aiming to reduce the current baseline prevalence of Campylobacter in retail chicken by 30% is predicted to yield approximately 30% relative risk reduction. A simulated one-log reduction in the mean concentration of Campylobacter is anticipated to generate approximately 20% relative risk reductions. Relative risk reduction induced by a one-log decrease in the mean was equally achieved when the tail of the input distribution was affected-that is, by a change (one-log reduction) in the standard deviation of the baseline Campylobacter concentration. A scenario assuming a 5% point decrease in baseline probability of cross-contamination at the consumer phase would yield relative risk reductions of 14%, which is as effective as the impact of a strategic target of 10% reduction in the retail prevalence of Campylobacter. In conclusion, the present model simulates the probability of illness predicted for an average individual who consumes salad that has been cross-contaminated with Campylobacter from retail chicken meat in WA. Despite some uncertainties, this is the first attempt to utilize the QMRA approach as a scientific basis to guide risk managers toward implementing strategies to reduce the risk of human campylobacteriosis in an Australian context.

Research Note: A baseline survey of thermotolerant Campylobacter in retail chicken in southern Brazil

Chicken is a leading source of thermotolerant Campylobacter, which triggers human foodborne enteritis. This study evaluated thermotolerant Campylobacter contamination of retail chicken in southern Brazil, using qualitative and quantitative analyses. Selective enrichment in Bolton broth for 24 and 48 h after plating onto modified charcoal-cefoperazone-deoxycholate (mCCD) agar and Preston agar was assessed. The combined results of the detection and enumeration methods revealed a frequency of 70% occurrence of thermotolerant Campylobacter in chicken samples. Campylobacter was enumerated in 60% of the samples, whereas 46% of the samples were positive in the qualitative analysis. Quantitative analysis showed average counts of 3.10 ± 0.15 log₁₀ CFU/sample. Higher numbers of Campylobacter-positive samples were found using 24-h enrichment before plating onto Preston agar (46%) than onto mCCD agar (2%). The majority of isolated strains were identified as Campylobacter jejuni, and Campylobacter coli was also found but to a lesser extent. Subtyping revealed a clear distinction between strains isolated from different chicken sources. The enriched samples plated onto mCCD agar showed extensive spreading of nonproducing extended-spectrum β-lactamases Proteus mirabilis that hampered the identification of Campylobacter colonies. P. mirabilis strains showed resistance to cefoperazone, trimethoprim, and polymyxin B present in broth and plate media used and were inhibited by rifampicin present in Preston agar. The results underline the effect of the spread of contaminant strains on Campylobacter cultures, which might be prevented using a recently revised International Organization for Standardization method for qualitative analysis of chicken.

Prevalence of Campylobacter coli and Campylobacter jejuni in Retail Chicken, Beef, Lamb, and Pork Products in Three Australian States

The aim of this study was to investigate the prevalence and distribution of Campylobacter species in a variety of fresh and frozen meat and offal products collected from retail outlets in New South Wales (NSW), Queensland (Qld), and Victoria (Vic). A total of 1,490 chicken, beef, lamb, and pork samples were collected from Australian supermarkets and butcher shops over a 2-year sampling period (October 2016 to October 2018). Campylobacter spp. were detected in 90% of chicken meat and 73% of chicken offal products (giblet and liver), with significantly lower prevalence in lamb (38%), pork (31%), and beef (14%) offal (kidney and liver). Although retail chicken meat was frequently contaminated with Campylobacter, the level of contamination was generally low. Where quantitative analysis was conducted, 98% of chicken meat samples, on average, had <10,000 CFU Campylobacter per carcass, with 10% <21 CFU per carcass. Campylobacter coli was the most frequently recovered species in chicken meat collected in NSW (53%) and Vic (56%) and in chicken offal collected in NSW (77%), Qld (59%), and Vic (58%). In beef, lamb, and pork offal, C. jejuni was generally the most common species (50 to 86%), with the exception of pork offal collected in NSW, where C. coli was more prevalent (69%). Campylobacter prevalence was significantly higher in fresh lamb (46%) and pork (31%) offal than in frozen offal (17 and 11%, respectively). For chicken, beef, and pork offal, the prevalence of Campylobacter spp. was significantly higher on delicatessen products compared with prepackaged products. This study demonstrated that meat and offal products are frequently contaminated with Campylobacter. However, the prevalence is markedly different in different meats, and the level of chicken meat portion contamination is generally low. By identifying the types of meat and offal products types that pose the greatest risk of Campylobacter infection to consumers, targeted control strategies can be developed.