Analysis of the baseline survey on the prevalence of Campylobacter in broiler batches and of Campylobacter and Salmonella on broiler carcasses, in the EU, 2008 - Part B: Analysis of factors associated with Campylobacter colonisation of broiler batches and

Avian campylobacteriosis, prevalence, sources, hazards, antibiotic resistance, poultry meat contamination, and control measures: a comprehensive review

Avian campylobacteriosis is a vandal infection that poses human health hazards. Campylobacter is usually colonized in the avian gut revealing mild signs in the infected birds, but retail chicken carcasses have high contamination levels of Campylobacter spp. Consequently, the contaminated avian products constitute the main source of human infection with campylobacteriosis and result in severe clinical symptoms such as diarrhea, abdominal pain, spasm, and deaths in sensitive cases. Thus, the current review aims to shed light on the prevalence of Campylobacter in broiler chickens, Campylobacter colonization, bird immunity against Campylobacter, sources of poultry infection, antibiotic resistance, poultry meat contamination, human health hazard, and the use of standard antimicrobial technology during the chicken processing of possible control strategies to overcome such problems.

Comparison and Correlation Analysis of Immune Function and Gut Microbiota of Broiler Chickens Raised in Double-Layer Cages and Litter Floor Pens

This study aimed to compare the immune function and gut microbiota between double-layer caged and litter floor pen-raised broiler chickens. Eighty meaty male chicks were selected and divided into cage group and litter floor group, with 20 replicates in each group. The broilers were raised in the same chicken house. The rearing density of the two rearing systems was same. The broilers were sampled on days 13 and 34. The results showed that compared with the cage group, the litter floor broilers had worse growth performance (23.24% increase in feed conversion ratio) in the early stage; better slaughter performance at day 42; stronger peripheral immune function (including higher lysozyme activity, T-cell ratio, Th-cell ratio, Tc-cell ratio, CD4/CD8, IL-10, B-cell ratio, IgG and IgA levels; and spleen immune-related gene expression); and stronger intestinal immune function (including higher ileum CD80, AvBD2, Mucin2, NF-κB, IL-8, IFN-γ/IL-4, and IgA mRNA expression levels and ileal mucosa sIgA levels). Compared with the cage group, the alpha diversity of ileum microbiota of the litter floor broilers was higher, and the relative abundance levels of litter breeding bacteria (Facklamia, Globicatella, and Jeotgalicoccus) and potential pathogenic bacteria (Streptococcus and Staphylococcus) were higher (P < 0.05). Through Spearman correlation analysis, it was found that enriched microbes in the ileum of litter floor broilers were positively correlated with immune function. In summary, compared with cage broilers, litter floor broilers had more potential pathogenic bacteria and litter breeding bacteria in the ileum, which may be one of the important reasons for the stronger immune function status. IMPORTANCE In China, the three-dimensional rearing system (cage) for broilers has gradually become a trend. In production, it was found that the incidence of disease in broiler chickens raised in cage systems was significantly higher than that of ground litter. Given that broilers raised on ground litter systems may be exposed to more environmental microbes, it is important to understand whether the rearing environment affects the function and status of the host immune system by altering the gut microbiota. In this study, rearing environment-derived gut microbes associated with stronger immune function in ground litter broilers were provided, which will provide new insights into strategies to target gut microbes to promote immune function and status in broilers raised in cages.

Estimation of the Production Economic Consequences of Stopping Partial Depopulation in Broiler Production

Simple Summary

Partial depopulation is often used in broiler production to optimize the use of the farm space and rear a larger number of broilers. However, it may increase the risk for the introduction of Campylobacter spp. in the poultry house. A simulation was performed to evaluate the production consequences of a Belgian poultry house performing a 25% partial depopulation at 35 days of age compared with a scenario where the entire flock is slaughtered at 42 days of age. The result showed that stopping partial depopulation leads to a substantial production and profit decrease. To compensate the loss, it would be necessary an increase in meat price.

Abstract

Partial depopulation is the removal and slaughter of part of a flock prior to the final slaughter age, and this practice allows broiler producers to optimize stocking density in broiler houses. However, this practice constitutes a serious break in farm biosecurity that can lead to the introduction of various pathogens in the flock, including Campylobacter spp. In this study, the production of a house performing partial depopulation of 25% of the flock at 35 days of age prior to the final slaughter at 42 days was compared with a production system where partial depopulation was not performed. The differences in production costs, profit, and technical performance parameters were evaluated. The model indicated that stopping partial depopulation reduces the production between 16 to 24%, which results in a 14% reduced profit per kg of live weight, and a 31% reduced profit per production cycle. To compensate the profit loss, it would be necessary to increase the meat price 3% from a starting price of 87.44 cents. For current conventional broiler production, it may be financially challenging to stop partial depopulation practices. Focusing on external biosecurity to avoid the introduction of Campylobacter into poultry houses may be the right compromise.

The Prevalence and Epidemiology of Salmonella in Retail Raw Poultry Meat in China: A Systematic Review and Meta-Analysis

Foodborne disease caused by Salmonella is an important public health concern worldwide. Animal-based food, especially poultry meat, is the main source of human salmonellosis. The objective of this study was to evaluate the prevalence and epidemiology of Salmonella contamination in raw poultry meat commercialized in China. Following the principle of systematic review, 98 sets of prevalence data were extracted from 74 publications conducted in 21 Chinese provincial regions. The random-effect model was constructed for subgrouping analysis by meat category, preservation type, and geographical location. The prevalence levels differed from high to low among raw poultry meat, including chicken, 26.4% (95% CI: 22.4-30.8%); pigeon, 22.6% (95% CI: 18.2-27.8%); duck, 10.1% (95% CI: 5.3-18.2%); and other poultry meat, 15.4% (95% CI: 12.0-19.5%). Prevalence data on the preservation type revealed that chilled poultry meat might be more likely to experience cross-contamination than non-chilled poultry meat in China. The distribution map of Salmonella for raw poultry meat showed that a higher prevalence level was found in the Shaanxi, Henan, Sichuan, and Beijing regions. All subgroups possessed high amounts of heterogeneity (I² > 75%). The scientific data regarding the differences in prevalence levels between meat category, preservation method, and geographical region sources might be useful to improve specific interventions to effectively control the incidence of Salmonella in poultry meat.

Antibiotic Usage and Resistance in Food Animal Production: What Have We Learned from Bangladesh?

Irrational and inappropriate use of antibiotics in commercial chicken and aquaculture industries can accelerate the antibiotic resistance process in humans and animals. In Bangladesh, the growing commercial chicken and aquaculture industries are playing significantly important roles in the food value chain. It is necessary to know the antibiotic usage practices and antibiotic resistance in food animal production to design rational policies, guidelines, and interventions. We conducted a narrative review to understand the level of antibiotic usage and resistance in food animal production in Bangladesh. Information about antibiotic usage in different food animal production systems, including commercial chickens and aquaculture in Bangladesh is inadequate. Only a few small-scale studies reported that the majority (up to 100%) of the broiler and layer chicken farms used antibiotics for treating and preventing diseases. However, numerous studies reported antibiotic-resistant bacteria of public health importance in commercial chicken, fish, livestock, and animal origin food. The isolates from different pathogenic bacteria were found resistant against multiple antibiotics, including quinolones, the third or fourth generation of cephalosporins, and polymyxins. Veterinary practitioners empirically treat animals with antibiotics based on presumptive diagnosis due to inadequate microbial diagnostic facilities in Bangladesh. Intensive training is helpful to raise awareness among farmers, feed dealers, and drug sellers on good farming practices, standard biosecurity practices, personal hygiene, and the prudent use of antibiotics. Urgently, the Government of Bangladesh should develop and implement necessary guidelines to mitigate irrational use of antibiotics in food animals using a multi-sectoral One Health approach.

Bacteriophage Therapy to Reduce Colonization of Campylobacter jejuni in Broiler Chickens before Slaughter

Campylobacteriosis is the most commonly reported gastrointestinal disease in humans. Campybacter jejuni is the main cause of the infection, and bacterial colonization in broiler chickens is widespread and difficult to prevent, leading to high risk of occurrence in broiler meat. Phage therapy represents an alternative strategy to control Campylobacter in poultry. The aim of this work was to assess the efficacy of two field-isolated bacteriophages against experimental infections with an anti-microbial resistant (AMR) Campylobacter jejuni strain. A two-step phage application was tested according to a specific combination between chickens’ rearing time and specific multiplicities of infections (MOIs), in order to reduce the Campylobacter load in the animals at slaughtering and to limit the development of phage-resistant mutants. In particular, 75 broilers were divided into three groups (A, B and C), and phages were administered to animals of groups B and C at day 38 (Φ 16-izsam) and 39 (Φ 7-izsam) at MOI 0.1 (group B) and 1 (group C). All broilers were euthanized at day 40, and Campylobacter jejuni was enumerated in cecal contents. Reductions in Campylobacter counts were statistically significant in both group B (1 log₁₀ colony forming units (cfu)/gram (gr)) and group C (2 log₁₀ cfu/gr), compared to the control group. Our findings provide evidence about the ability of phage therapy to reduce the Campylobacter load in poultry before slaughtering, also associated with anti-microbial resistance pattern.

Overview of the Use of Probiotics in Poultry Production

Simple Summary

Probiotics are feed additives that have gained popularity in poultry production following the ban of antibiotic growth promoters (AGP). They are one of the more universal feed additives and can be easily combine with other additives. Probiotics, above all, have many advantages, including stimulation of the host microflora or immunomodulation. The statement “immunity comes from the intestines” has become more important in the poultry industry because probiotics have proven helpful in the fight against diseases of bacterial origin and against zoonoses. Positive effects on the organism have already been studied at the cellular level, where probiotics were responsible for changes in gene expression, leading to alleviation of heat stress. In addition to the health benefits, the utility value of the animals increases. The numerous advantages are overshadowed by a few drawbacks, which include the possibility of lowering semen quality in roosters and the diversity of production processes affecting the persistence of the probiotic. In addition to bird health, probiotics have improved the taste and quality of poultry products. Future prospects are promising as scientists are working to maximize the positive effects of probiotics by increasing the integrity of probiotics within the bird organism, taking into account, among others, bacterial metabolites.

Abstract

In recent years, probiotics have become more popular in the world of dietary supplements and feed additives within the poultry industry, acting as antibiotic substitutes. Above all, probiotics are universal feed additives that can be used in conjunction with other additives to promote improved performance and health. Their positive effects can be observed directly in the gastrointestinal tract and indirectly in immunomodulation of the poultry immune system. Nutritional effects seen in flocks given probiotics include increased laying and egg quality, increased daily increments, and improved feed conversion ratio (FCR). There has also been an improvement in the quality of meat. This suggests producers can improve production results through the use of probiotics. In addition to these production effects, bird immunity is improved by allowing the organism to better protect itself against pathogens and stress. The lack of accuracy in the formulation of non-European preparations needs to be further developed due to unknown interactions between probiotic bacteria strains as well as their metabolites. The versatility of probiotics and the fact that the bacteria used in their production are an integral part of animal digestive tracts make them a safe feed additives. Despite restrictions from the European Union, probiotics have potential to improve production and health within the poultry industry and beyond. The following article will review the use of probiotics in poultry production.

Antimicrobial Resistance, FlaA Sequencing, and Phylogenetic Analysis of Campylobacter Isolates from Broiler Chicken Flocks in Greece

Human campylobacteriosis caused by thermophilic Campylobacter species is the most commonly reported foodborne zoonosis. Consumption of contaminated poultry meat is regarded as the main source of human infection. This study was undertaken to determine the antimicrobial susceptibility and the molecular epidemiology of 205 Campylobacter isolates derived from Greek flocks slaughtered in three different slaughterhouses over a 14-month period. A total of 98.5% of the isolates were resistant to at least one antimicrobial agent. In terms of multidrug resistance, 11.7% of isolates were resistant to three or more groups of antimicrobials. Extremely high resistance to fluoroquinolones (89%), very high resistance to tetracycline (69%), and low resistance to macrolides (7%) were detected. FlaA sequencing was performed for the subtyping of 64 C. jejuni and 58 C. coli isolates. No prevalence of a specific flaA type was observed, indicating the genetic diversity of the isolates, while some flaA types were found to share similar antimicrobial resistance patterns. Phylogenetic trees were constructed using the neighbor-joining method. Seven clusters of the C. jejuni phylogenetic tree and three clusters of the C. coli tree were considered significant with bootstrap values >75%. Some isolates clustered together were originated from the same or adjacent farms, indicating transmission via personnel or shared equipment. These results are important and help further the understanding of the molecular epidemiology and antimicrobial resistance of Campylobacter spp. derived from poultry in Greece.

Prevalence of Campylobacter spp. in Chicken Carcasses in Slaughterhouses from South of Brazil

Campylobacteriosis has become common cause of diarrhea in humans and is associated with Guillain-Barré Syndrome, Reactive Arthritis and Irritable Bowel Syndrome is caused mainly by contaminated food and water intake in which the majority occurs from manipulation, preparation and consumption of poultry meat. The aim of this study was to estimate the prevalence of Campylobacter in chicken carcasses from slaughterhouses located in the states of Parana, Santa Catarina and Rio Grande do Sul in the South of Brazil. The samples were analyzed for Campylobacter enumeration using the ISO method 10272-2 and the species C. jejuni and C. coli, important for public health, were identified through Maldi-TOF mass spectrometry. From July 2017 to July 2018, 816 samples were analyzed, indicating the prevalence of 35.84%, with higher occurrence of C. jejuni (78.47%). No difference in prevalence was observed in relation to the size of the slaughterhouses. However, significant differences were noted among the three states in the southern region of the country, with the lowest prevalence being observed in Parana. The results reinforce the need to advance in the implementation of strategies to control this pathogen in the country, in order to safeguard consumer's health and contribute for the maintenance of Brazil's position in the international poultry meat market.

Using farm management practices to predict Campylobacter prevalence in pastured poultry farms

Contamination of poultry products by Campylobacter is often associated with farm management practices and processing plant practices. A longitudinal study was conducted on 11 pastured poultry farms in southeastern United States from 2014 to 2017. In this study, farm practices and processing variables were used as predictors for a random forest (RF) model to predict Campylobacter prevalence in pastured poultry farms and processing environments. Individual RF models were constructed for fecal, soil and whole carcass rinse after processing (WCR-P) samples. The performance of models was evaluated by the area under curve (AUC) from the receiver operating characteristics curve. The AUC values were 0.902, 0.894, and 0.864 for fecal, soil, and WCR-P models, respectively. Relative importance plots were generated to predict the most important variable in each RF model. Animal source of feces was identified as the most important variable in fecal model and the soy content of the brood feed was the most important variable for soil model. For WCR-P model, the average flock age showed the strongest impact on RF model. These RF models can help pastured poultry growers with food safety control strategies to reduce Campylobacter prevalence in pastured poultry farms.

The Data Behind Risk Analysis of Campylobacter Jejuni and Campylobacter Coli Infections

Campylobacter jejuni and Campylobacter coli are major causes of food-borne enteritis in humans. Poultry meat is known to be responsible for a large proportion of cases of human campylobacteriosis. However, other food-borne, environmental and animal sources are frequently associated with the disease in humans as well. Human campylobacteriosis causes gastroenteritis that in most cases is self-limiting. Nevertheless, the burden of the disease is relatively large compared with other food-borne diseases, which is mostly due to rare but long-lasting symptoms related to immunological sequelae. In order to pave the way to improved surveillance and control of human campylobacteriosis, we review here the data that is typically used for risk analysis to quantify the risk and disease burden, identify specific surveillance strategies and assist in choosing the most effective control strategies. Such data are mostly collected from the literature, and their nature is discussed here, for each of the three processes that are essential for a complete risk analysis procedure: risk assessment, risk management and risk communication. Of these, the first, risk assessment, is most dependent on data, and this process is subdivided into the steps of hazard identification, hazard characterization, exposure assessment and risk characterization. For each of these steps of risk assessment, information from published material that is typically collected will be summarized here. In addition, surveillance data are highly valuable for risk assessments. Different surveillance systems are employed in different countries, which can make international comparison of data challenging. Risk analysis typically results in targeted control strategies, and these again differ between countries. The applied control strategies are as yet not sufficient to eradicate human campylobacteriosis. The surveillance tools of Campylobacter in humans and exposure sources in place in different countries are briefly reviewed to better understand the Campylobacter dynamics and guide control strategies. Finally, the available control measures on different risk factors and exposure sources are presented.

Management Strategies for Prevention of Campylobacter Infections Through the Poultry Food Chain: A European Perspective

Numerous studies point out that at present, a complete elimination of Campylobacter species in the poultry food chain is not feasible. Thus, the current aim should be to establish control measures and intervention strategies to minimize the occurrence of Campylobacter spp. in livestock (esp. poultry flocks) and to reduce the quantitative Campylobacter burden along the food chain in animals and subsequently in foods. The most effective measures to mitigate Campylobacter focus on the primary production stage. Nevertheless, measures applied during slaughter and processing complement the general meat hygiene approaches by reducing fecal contamination during slaughtering and processing and as a consequence help to reduce Campylobacter in poultry meat. Such intervention measures at slaughter and processing level would include general hygienic improvements, technological innovations and/or decontamination measures that are applied at single slaughter or processing steps. In particular, approaches that do not focus on a single intervention measure would need to be based on a thorough process of evaluation, and potential combinatory effects have to be modeled and tested. Finally, the education of all stakeholders (including retailers, food handlers and consumers) is required and will help to increase awareness for the presence of foodborne pathogens in raw meat and meat products and can thus aid in the development of the required good kitchen hygiene.

Prevalence, Antimicrobial Susceptibility, Virulence and Genotyping of Campylobacter jejuni with a Special Reference to the Anti-Virulence Potential of Eugenol and Beta-Resorcylic Acid on Some Multi-Drug Resistant Isolates in Egypt

Campylobacter jejuni is the leading cause of foodborne bacterial gastroenteritis in humans worldwide. Contaminated chickens and their products are the main sources of human campylobacteriosis. Therefore, this study aimed to detect the genotypic and virulence genes' profiles of multi-drug resistant (MDR) C. jejuni isolates and to assess the effects of sub-inhibitory concentrations (SICs) of eugenol and beta-resorcylic acid on the virulence of avian MDR C. jejuni isolates. These isolates were clustered together with the human isolates via enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) fingerprinting. A total of 345 samples were collected from human stool (100) and different chicken (245) samples in Sharkia Governorate, Egypt. Conventional phenotypic methods identified 113 isolates (32.8%) as C. jejuni, and all C. jejuni isolates were MDR and resistant to erythromycin and ampicillin. The genes virB11, wlaN, and flaA were detected in 52%, 36% and 100% strains, respectively. ERIC-PCR yielded 14 profiles and five main clusters. Interestingly, human and chicken C. jejuni isolates were clustered together in ERIC-PCR clusters II-V, which confirmed the genetic relatedness between the isolates from both origins. Beta-resorcylic acid and eugenol inhibited the invasion of C. jejuni isolates to chicken intestinal cells by 41.66-38.19% and 31.94-29.16%, respectively, and minimized the transcription of flaA, virB11, and wlaN genes in the tested isolates by real-time quantitative reverse transcription PCR (qRT-PCR). In essence, eugenol and beta-resorcylic acid are promising natural antimicrobials for minimizing the virulence of MDR C. jejuni in chickens, thereby managing human campylobacteriosis.

Occurrence of Campylobacter spp. in Selected Small Scale Commercial Broiler Farms of Bangladesh Related to Good Farm Practices

Poultry origin Campylobacter is considered as one of the leading causal agents of human foodborne illness. This study was conducted to estimate the occurrence, molecular identification, and antimicrobial resistance (AMR) of Campylobacter species from the broiler farms in Bangladesh. Samples (352) were collected from 32 farms and comprised of 128 cloacal swab, 64 feed, 64 drinking water, 64 attendants' hand rinsed water, and 32 whole carcasses. All samples were tested for the presence of Campylobacter via cultural, biochemical, and PCR. The AMR was determined via the disc diffusion method. An overall occurrence of Campylobacter spp. was estimated as 26.4%. The level of Campylobacter contamination was found to be higher in conventional farms (36.4%) than the good practice farms (16.5%) including all sample categories (p = 0.000). Of 93 isolates, 67.74% and 32.26% were confirmed as C. jejuni and C. coli respectively, of which 34.92% C. jejuni, and 30% C. coli were shown to be multidrug-resistant. A significant occurrence of Campylobacter contamination in broiler farms with multidrug resistant patterns might be cogitated as serious food safety and public health concern linking to poultry food chain. A risk reduction approach through good farming practices targeting the prudent use of antimicrobials for broiler production is thus necessitated.

Prevalence of Campylobacter spp. in a poultry and pork processing plants

The study aimed to investigate the prevalence of Campylobacter spp. in different stages of poultry and pork processing in the Central region of Russia. A total of 47 Campylobacter isolates were obtained from 107 samples from poultry processing plants (40.2%): 87.2% were identified as Campylobacter jejuni, whereas 12.8% were identified as Campylobacter coli. The prevalence of Campylobacter was significantly (p <0.05) higher after evisceration in the poultry processing plant. Campylobacter spp.was detected in 62.7% of the equipment and environmental samples. From positive samples of Campylobacter spp., 84.3% of Campylobacter jejuni and 15.7% Campylobacter coli were observed. A total of nine Campylobacter isolates were obtained from 116 samples from pork processing plants (7.8%): 33.3% of them were identified as Campylobacter jejuni whereas 66.7% were identified as Campylobacter coli. Splitting and evisceration were also critical in Campylobacter contamination. Almost all pork carcasses were Campylobacter positive, and all of them were identified as Campylobacter coli. The prevalence of positive Campylobacter samples in poultry processing plants was significantly (p < 0.05) higher than in pork processing plants.

Prevalence and antibiotic resistance of Campylobacter coli isolated from broiler farms in the Marrakesh Safi region, Morocco

Background and Aim

Campylobacteriosis is a common foodborne disease epidemiologically linked to the consumption of poultry products. However, other sources, such as raw or contaminated milk, contaminated water or ice, contact with infected livestock, and pets, are reported. This study aimed to evaluate the prevalence and resistance to microbial resistance of Campylobacter coli in broiler farms in the region of Marrakesh Safi, Morocco.

Materials and Methods

The study was conducted between May and December 2017 and involved 35 broiler farms. One hundred and five cloacal swabs were collected from the eight provinces in the region of Marrakesh Safi, Morocco. Bacteriology method NM ISO/TS 10272-3: 2013 was used to isolate and identify Campylobacter spp. Molecular identification (polymerase chain reaction) was used for confirmation. A disk diffusion method on Mueller-Hinton agar was used for susceptibility testing. Five antibiotic agents, including first-line drugs, were evaluated.

Results

Among 105 samples, 71.4% (75/105) were positive for Campylobacter spp. test and 56% (42/75) of isolates belonged to the species coli. Susceptibility profiles showed that 95.2% of C. coli strains were resistant to ampicillin, 92.8% to erythromycin and tetracycline, 85.7% to ciprofloxacin, and 7.1% to gentamicin.

Conclusion

This study underlines the need to strengthen implementation of specific control procedures to decrease contamination of poultry meat with Campylobacter spp. and to reduce the use of antibiotics in the poultry sector.

Pathogenicity of Campylobacter strains of poultry and human origin from Poland

The aim of this study was to determine the pathogenic markers associated with Campylobacter infection in humans. A total of 104 Campylobacter isolates obtained from poultry and humans were examined for the presence of nine virulence genes and their ability to adhere to, invade and produce cytotoxin were defined using HeLa cells. The diversity of the Campylobacter spp. isolates was studied based on sequencing of the SVR-region of flaA gene. Altogether 45 flaA-SVR alleles were identified among 104 Campylobacter isolates of poultry and human origin. All Campylobacter isolates possessed flaA, cadF and racR genes involved in adherence. Accordingly, all poultry and human isolates exhibited adherence towards HeLa cells at mean levels of 0.95% and 0.82% of starting viable inoculum, respectively. The genes involved in invasion (iam and pldA) and cytotoxin production (cdtA, cdtB and cdtC) were also widely distributed among the human and poultry Campylobacter isolates. Significantly higher invasiveness was observed for poultry isolates (mean level of 0.002% of starting bacterial inoculum) compared to human isolates (0.0005%). Interestingly the iam gene, associated with invasion, was more common in human (100%) than poultry (84%) isolates, and the poultry isolates lacking the iam gene showed a marked reduction in their ability to invade HeLa cells. Moreover, virB11 was present in 22% of the poultry and 70.4% of the human isolates. Strains lacking virB11 showed a slight reduction in invasion, however in the absence of iam even the poultry isolates containing virB11 were unable to invade HeLa cells. The mean cytotoxicity of Campylobacter isolates from poultry and human was 26.7% and 38.7%, respectively. Strains missing both the cdtB and cdtC genes were non-cytotoxic compared to strains containing all three cdtABC genes, which were the most cytotoxic among the C. jejuni and C. coli isolates from both sources. No cytotoxic effect was observed in only 4% of poultry and 5.6% of human isolates.

Molecular epidemiology of Campylobacter jejuni isolates from the broiler production chain: first report of MLST profiles in Argentina

Campylobacter jejuni is an important foodborne pathogen with global distribution. We describe a genotyping study of a collection of C. jejuni (n=137) isolated from different broiler farms and from multiple sites along the processing line in a slaughterhouse in Argentina during 2011, 2012 and 2015. The isolates were genotyped using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Based on the PFGE results, the isolates were grouped into 26 pulsotypes. Subsequently, the isolates representing these 26 pulsotypes were chosen for MLST genotyping, which identified 16 different sequence types (STs) and 6 clonal complexes (CCs) (21, 45, 48, 353, 354, 446). Several of the STs (n=7) have not been previously reported in the PubMLST.org database. The most prevalent CCs were 21, 45 (both associated with human campylobacteriosis worldwide) and 353. This study showed high genetic diversity among C. jejuni in the broiler production environment in Argentina with novel MLST genotypes.

In vivo efficacy of carvacrol on Campylobacter jejuni prevalence in broiler chickens during an entire fattening period

Carvacrol, a primary constituent of plant essential oils (EOs), and its antimicrobial activity have been the subject of many in vitro studies. Due to an increasing demand for alternative antimicrobials and an emerging number of antibiotic resistant bacteria, the use of essential oils has played a major role in many recent approaches to reduce Campylobacter colonization in poultry before slaughter age. For that purpose, the reducing effect of carvacrol on Campylobacter jejuni prevalence in broilers was determined in vivo in an experimental broiler chicken model during an entire fattening period. Carvacrol was added to the feed in a concentration of 120 mg/kg feed four days post hatch until the end of the trial. In this study, we demonstrated a statistically significant decrease of C. jejuni counts by 1.17 decadic logarithm (log10) most probable number (MPN)/g in cloacal swabs during starter and grower periods (corresponding to a broilers age between 1 and 28 days). Similar results were observed for colon enumeration at the end of the trial where C. jejuni counts were significantly reduced by 1.25 log10 MPN/g. However, carvacrol did not successfully reduce Campylobacter cecal colonization in 33-day-old broilers.

Prevalence, molecular detection, and virulence gene profiles of Campylobacter species in humans and foods of animal origin

BACKGROUND AND AIM

Campylobacteriosis is one of the most well-characterized bacterial foodborne infections worldwide that arise chiefly due to the consumption of foods of animal origin such as poultry, milk, and their products. The disease is caused by numerous species within the genus Campylobacter, but Campylobacter jejuni is the most commonly isolated species from established cases of human campylobacteriosis. This study was conducted to determine the prevalence and virulence of Campylobacter isolates from human, chicken, and milk and milk products in Egypt.

MATERIALS AND METHODS

A total of 1299 samples (547 chicken intestine and liver, 647 milk and milk products, and 105 human stool) were collected and microbiologically investigated, confirmed by multiplex polymerase chain reaction (PCR) targeting the 23S rRNA, hipO, and glyA genes specific for Campylobacter spp., C. jejuni, and Campylobacter Coli, respectively, followed by virulence genes (Campylobacter adhesion to fibronectin F [cadF] and cdtB) detection using PCR.

RESULTS

About 38.09%, 37.84%, and 8.5% of human stool, chicken, and milk and milk product samples, respectively, were bacteriologically positive, with a total of 302 Campylobacter isolates. All isolates were molecularly confirmed as Campylobacter spp. (100%) where 285 isolates (94.37%) were identified as C. jejuni and 17 isolates (5.62%) as C. coli. Regarding the virulence pattern, all isolates (100%) carried cadF gene while cytolethal distending toxin B gene was definite in 284/302 isolates (94%), concisely, 282/285 (98.94%) C. jejuni isolates, and in 2/17 (11.76%) C. coli isolates.

CONCLUSION

The widespread presence of these highly virulent Campylobacter, especially C. jejuni, proofs the urgent need for the implementation of stringent control, public health, and food protection strategies to protect consumers from this zoonotic pathogen. The availability of information about pathogen virulence will enable enhanced local policy drafting by food safety and public health officials.

Molecular identification and antibiotic resistance profiling of Salmonella species isolated from chickens in eastern Turkey

BACKGROUND

The aim of this study was to obtain quantitative data about the frequency, genotypic characterization and antibiotic resistance profiling of Salmonella agents in chicken flocks located in eastern Turkey.

RESULTS

Feces samples representing at least 20% of the flock area were collected via sock swabs from commercial poultry flocks in the study region in addition to internal organs (liver, spleen, intestine) collected at necropsy of suspected chickens belonging to small family enterprises. The samples were analyzed by conventional bacteriological methods (ISO 6579:2002/A1:2007) for isolation, and genus specific (invA) PCR for the identification of Salmonella spp. Then, two mPCR were set up to determine Salmonella serotypes and genotypic resistance status of the field isolates against ampicillin, tetracycline, trimethoprim-sulfamethoxazole and chloramphenicol antibiotics. In the PCR analysis of the suspected colonies, 98.5% were confirmed as Salmonella spp., and, the most prevalent serotype was identified as S. Infantis with the proportion of 26.6% (17/64), followed by S. Enteritidis with 21.9% (14/64) and S. Typhimurium with 9.4% (6/64). The findings related to antibiotic resistance genes revealed that the most frequently determined gene was sul1 with approximately 58%, while the blaTEM gene was detected at the lowest proportion with 20%, among Salmonella isolates.

CONCLUSIONS

The results indicated that Salmonella infections constitute a potential risk for chicken flocks in the country and that genotypic resistance rates against various antibiotics should draw particular attention in terms of both human and animal health.

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.

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.

Antimicrobial Resistance and Virulence Properties of Campylobacter Spp. Originating from Domestic Geese in Poland

A total of 240 samples were evaluated for the presence of Campylobacter spp. Campylobacter was found in 83.3% of the cecum contents samples and 52.5% of the neck skin samples from carcasses. The prevailing species was C. jejuni, accounting for 87.7% of all Campylobacter isolates, and the remaining 12.3% of isolates were C. coli. All Campylobacter isolates, independent of the sample origin and species, were positive for 6 out of 15 tested genes (flaA, flhA, cadF, racR, ciaB, and cdtA genes). The prevalence of dnaJ, docA, pldA, cdtB, cdtC, and iam genes was also very common (ranging from 86.5% to 98.8%). The lowest prevalence was noted for virB11 and wlaN genes, both in Campylobacter isolates from cecum (12% and 19%) and carcasses (11.1% and 17.5%). None of the isolates tested, regardless of the sample origin, carried the cgtB gene. The highest resistance rates were observed for quinolones (90.8%) and tetracyclines (79.8%). Simultaneously, only single Campylobacter isolate was resistant to macrolides (0.6%) and none of the isolates showed resistance to aminoglycosides and amphenicols. The common presence of Campylobacter on geese carcasses as well as the detection of multidrug-resistant isolates indicate that consuming goose meat might cause a potential risk, therefore leading to human campylobacteriosis.

Thermotolerant Campylobacter spp. in chicken and bovine meat in Italy: Prevalence, level of contamination and molecular characterization of isolates

Campylobacter species are common foodborne pathogens associated with cases of human gastroenteritis worldwide. A detailed understanding of the prevalence, contamination levels and molecular characteristics of Campylobacter spp. in cattle and chicken, which are likely the most important sources of human contamination, is imperative. A collection of 1243 poultry meat samples (665 chicken breasts and 578 chicken thighs) and 1203 bovine meat samples (689 hamburgers and 514 knife-cut meat preparations) were collected at retail outlets, in randomly selected supermarkets located in different Italian regions during one year. Of these samples, 17.38% of the poultry meat and 0.58% of the bovine meat samples tested positive for Campylobacter, of which 131 were Campylobacter jejuni (57.96%) and 95 were Campylobacter coli (42.03%). Campylobacter isolates were genotyped with the aim of assessing the genetic diversity, population structure, source distribution and Campylobacter transmission route to humans. All isolates were molecularly characterized by pulse field gel electrophoresis (PFGE), and further genotyped using multilocus sequence typing (MLST) and fla-SVR sequencing to gain better insight into the population structure. Antibiotic resistance was also investigate. The highest levels of resistance among chicken strains were observed for ciprofloxacin (88.25%), nalidixic acid (81.45%) and tetracycline (75.6%). PFGE analysis revealed 73 pulsotypes for C. jejuni and 54 pulsotypes for C. coli, demonstrating the existance of different and specific clones circulating in Italy. MLST of C.jejuni isolates mainly clustered in the CC353, CC354, CC21, CC206 and CC443; while C.coli isolates clustered only in CC828. The most common flaA alleles were 287 for C. jejuni and 66 for C. coli. Our study confirms that poultry meat is the main source of Campylobacteriosis, whereas red meat had a low level of contamination suggesting a minor role in transmission. The high presence of Campylobacter in retail chicken meat, paired with its increased resistance to antimicrobials with several multidrug resistance profiles detected, is alarming and represents a persistent threat to public health.

Viability Quantitative PCR Utilizing Propidium Monoazide, Spheroplast Formation, and Campylobacter coli as a Bacterial Model

A viability quantitative PCR (qPCR) utilizing propidium monoazide (PMA) is presented for rapid quantification of viable cells using the foodborne pathogen Campylobacter coli as a bacterial model. It includes optimized spheroplast formation via lysozyme and EDTA, induction of a mild osmotic shock for enhancing the selective penetration of PMA into dead cells, and exploitation of an internal sample process control (ISPC) involving cell inactivation to assess residual false-positive signals within each sample. Spheroplasting of bacteria in exponential phase did not permit PMA entrance into viable cells since a strong linear relationship was detected between simple qPCR and PMA-qPCR quantification, and no differences were observed regardless of whether spheroplasting was utilized. The PMA-qPCR signal suppression of dead cells was elevated using spheroplast formation. With regard to the ISPC, cell inactivation by hydrogen peroxide resulted in higher signal suppression during qPCR than heat inactivation did. Viability quantification of C. coli cells by optimized spheroplasting-PMA-qPCR with ISPC was successfully applied in an aging pure culture under aerobic conditions and artificially inoculated meat. The same method exhibited a high linear range of quantification (1.5 to 8.5 log10 viable cells ml-1), and results were highly correlated with culture-based enumeration. PMA-qPCR quantification of viable cells can be affected by their rigidity, age, culture media, and niches, but spheroplast formation along with osmotic shock and the use of a proper ISPC can address such variations. The developed methodology could detect cells in a viable-but-nonculturable state and might be utilized for the quantification of other Gram-negative bacteria.IMPORTANCE There is need for rapid and accurate methods to detect viable bacterial cells of foodborne pathogens. Conventional culture-based methods are time-consuming and unable to detect bacteria in a viable-but-nonculturable state. The high sensitivity and specificity of the quantitative PCR (qPCR) are negated by its inability to differentiate the DNAs from viable and dead cells. The combination of propidium monoazide (PMA), a DNA-intercalating dye, with qPCR assays is promising for detection of viable cells. Despite encouraging results, these assays still encounter various challenges, such as false-positive signals by dead cells and the lack of an internal control identifying these signals per sample. The significance of our research lies in enhancing the selective entrance of PMA into dead Campylobacter coli cells via spheroplasting and in developing an internal sample process control, thus delivering reliable results in pure cultures and meat samples, approaches that can be applicable to other Gram-negative pathogens.

Phenotypic and Genotypic Characterization of Antimicrobial Resistance in Salmonella Strains Isolated from Chicken Carcasses and Parts Collected at Different Stages during Processing

Chicken carcass and parts rinsate samples and fecal samples were collected at different stages in a commercial poultry processing facility. Microbiological analysis was conducted to determine the levels of multiple indicator microorganisms and prevalence of Salmonella. Antibiotic susceptibility testing was conducted on Salmonella isolates to determine antimicrobial resistance profiles. Whole genome sequencing was performed for tracing isolates in the processing chain, serotyping, and determining genetic features associated with virulence and antimicrobial resistance in the bacterial genome. The overall contamination rate was 55% for Salmonella. Prevalence increased by 80% in chicken parts compared with the previous processing site (postchill carcasses), suggesting possible cross-contamination during the cutting and deboning processes. The levels of indicator organisms were reduced significantly from the prescalding to the parts processing sites, by 3.22 log CFU/mL for aerobic plate count, 3.92 log CFU/mL for E. coli, 3.70 log CFU/mL for coliforms, and 3.40 log CFU/mL for Enterobacteriaceae. The most frequent resistance in Salmonella was associated with tetracycline (49 of 50, 98%) and streptomycin (43 of 50, 86%). Some Salmonella isolates featured resistance to the cephems class of antibiotics (up to 15%). Whole genome sequencing analysis of Salmonella isolates identified nine different clonal populations distributed throughout the samples taken at different stages; serotype Kentucky was the most commonly isolated. This study provides insights into microbial profiling and antibiotic-resistant strains of chicken rinsate samples during poultry processing.

Salmonella control in poultry flocks and its public health impact

An increase in confirmed human salmonellosis cases in the EU after 2014 triggered investigation of contributory factors and control options in poultry production. Reconsideration of the five current target serovars for breeding hens showed that there is justification for retaining Salmonella Enteritidis, Salmonella Typhimurium (including monophasic variants) and Salmonella Infantis, while Salmonella Virchow and Salmonella Hadar could be replaced by Salmonella Kentucky and either Salmonella Heidelberg, Salmonella Thompson or a variable serovar in national prevalence targets. However, a target that incorporates all serovars is expected to be more effective as the most relevant serovars in breeding flocks vary between Member State (MS) and over time. Achievement of a 1% target for the current target serovars in laying hen flocks is estimated to be reduced by 254,400 CrI95[98,540; 602,700] compared to the situation in 2016. This translates to a reduction of 53.4% CrI95[39.1; 65.7] considering the layer-associated human salmonellosis true cases and 6.2% considering the overall human salmonellosis true cases in the 23 MSs included in attribution modelling. A review of risk factors for Salmonella in laying hens revealed that overall evidence points to a lower occurrence in non-cage compared to cage systems. A conclusion on the effect of outdoor access or impact of the shift from conventional to enriched cages could not be reached. A similar review for broiler chickens concluded that the evidence that outdoor access affects the occurrence of Salmonella is inconclusive. There is conclusive evidence that an increased stocking density, larger farms and stress result in increased occurrence, persistence and spread of Salmonella in laying hen flocks. Based on scientific evidence, an impact of Salmonella control programmes, apart from general hygiene procedures, on the prevalence of Campylobacter in broiler flocks at the holding and on broiler meat at the end of the slaughter process is not expected.

Enhanced Systemic Response of Matrix Metalloproteinases and Their Regulators in Campylobacter and Salmonella Patients

Campylobacters are major enteropathogens worldwide with a substantial financial burden. Matrix metalloproteinases (MMPs) are proteolytic metalloendopeptidases with ability to modify immune response and shown to be upregulated in patients with several tissue destructive diseases, including infections. We measured here serum concentrations of MMP-8 and MMP-9 together with their regulators myeloperoxidase (MPO), human neutrophil elastase (HNE), and tissue inhibitor of metalloproteinases (TIMP)-1 in 80 Campylobacter and 25 Salmonella patients as well as in 27 healthy controls. Paired serum samples were available for 73 and 23 patients, respectively. When the initial serum samples were compared to those from controls, both Campylobacter and Salmonella patients showed elevated concentrations of all biomarkers tested (p ≤ 0.037). In the follow-up samples, collected about 25 days afterwards, MMP-8 levels of Campylobacter patients had already turned to normal but all the other biomarkers still showed elevated, although from the initial levels significantly dropped, levels. For the follow-up samples of Salmonella patients, only MMP-9 and MPO levels were at a significantly higher level than in controls. It remains to be studied if the systematically enhanced neutrophil-derived proteolytic and oxidative stress, induced by Campylobacter infection as shown here and persisting for several weeks, is important for the development of late sequelae.

Qualitative and Quantitative Determination and Resistance Patterns of Salmonella from Poultry Carcasses

Poultry products are important in the transmission of zoonotic pathogens, mainly Salmonella. This genus causes millions of foodborne diseases worldwide every year. Cross-contamination by food sources in human cases of salmonellosis and the increase in resistant strains have become important issues. A qualitative and quantitative Salmonella detection method was utilized in a poultry slaughterhouse in São Paulo State, Brazil. We collected 33 samples from different batches of carcasses. Each sample was analyzed at three process points: postbleeding, postdefeathering, and postchilling. A fourth point, retail simulation, was added to simulate retail market storage at 5°C for 72 h. The qualitative methods revealed 100% (33 samples) contamination at postbleeding, 39% (13 samples) contamination at postdefeathering, 58% (19 samples) contamination at postchilling, and 30% (10 samples) contamination at the retail simulation. The quantitative results, determined by the most-probable-number (MPN) technique, ranged from <0.03 to >2,400 MPN/g. We identified 23 Salmonella serovars; the most prevalent were Mbandaka, Senftenberg, and Enteritidis. Resistance to nalidixic acid was significantly more common (P < 0.05) than resistance to other antimicrobial agents. Five multidrug-resistant strains were identified. This study contributes important epidemiological data and demonstrates the need to improve sanitary conditions in slaughterhouses.

The impact of biosecurity and partial depopulation on Campylobacter prevalence in Irish broiler flocks with differing levels of hygiene and economic performance

Background

Campylobacter jejuni is the leading bacterial food-borne pathogen within the European Union (EU), and poultry meat is the primary route for transmission to humans.

Material and methods

This study examined the impact of partial depopulation (thinning), season, and farm performance (economic, hygiene, and biosecurity) on Campylobacter prevalence in Irish broilers over a 13-month period. Ten caecal samples were taken per flock, for a total of 211 flocks from 23 farms during the duration of the study. Campylobacter was isolated and enumerated according to modified published ISO methods for veterinary samples. Biosecurity was evaluated through a questionnaire based on risk factors for Campylobacter identified in previous studies. Hygiene compliance was assessed from audit records taken over the course of 1 year. All information relating to biosecurity and hygiene was obtained directly from the processing company. This was done to ensure farmers were unaware they were being monitored for Campylobacter prevalence and prevent changes to their behaviour.

Results and discussion

Farms with high performance were found to have significantly lower Campylobacter prevalence at first depopulation compared with low-performance farms across all seasons (P≤0.01). Peak Campylobacter levels were observed during the summer season at first thin in both the high- and low-performance groups. Campylobacter prevalence was found to increase to ≥85% in both high- and low-performance farms across all seasons at final depopulation, suggesting that Campylobacter was introduced during the first depopulation. On low-performance farms, four biosecurity interventions were found to significantly reduce the odds of a flock being Campylobacter positive (physical step-over barrier OR=0.17, house-specific footwear OR=0.13, absence of water body within 0.5 km OR=0.13, two or more broiler houses on a farm OR=0.16), compared with farms without these interventions. For high-performance farms, no single biosecurity intervention was identified as significant as this group had full compliance with multiple factors. High-performance farms had significantly better feed conversion ratios compared with low-performance farms (1.61 v 1.67 (P≤0.01)). No differences in flock mortality rates were observed (P≥0.05). This highlights the impact of season, biosecurity, partial depopulation, and farm performance on Campylobacter prevalence in Irish broilers.

A comparison of fluctuations of Campylobacter and Escherichia coli concentrations on broiler chicken carcasses during processing in two slaughterhouses

The causes of differences in Campylobacter and Escherichia coli concentrations on broiler chicken carcasses after chilling between slaughterhouses are not fully identified. Therefore, it is a challenge for slaughterhouses to comply with Process Hygiene Criteria for broiler meat. The aim of the study was to identify which processing steps contribute to increases or decreases in Campylobacter and E. coli concentrations within and between two slaughterhouses. Identifying the processing steps with variable performance could explain the differences in bacterial concentrations after chilling between slaughterhouses. Thermotolerant Campylobacter and E. coli concentrations on carcasses during broiler processing were measured during the summer period in 21 trials after bleeding, scalding, defeathering, evisceration and chilling. In two slaughterhouses with comparable Campylobacter and E. coli concentrations in the incoming batches (after bleeding), the mean log10 concentrations are found to be significantly different after chilling. Campylobacter concentrations decreased by 1.40 log10 in Slaughterhouse 1 and by 1.86 log10 in Slaughterhouse 2, whereas E. coli decreased by 2.19 log10 in Slaughterhouse 1 and by 2.84 log10 in Slaughterhouse 2. Higher concentrations of Campylobacter and E. coli on carcasses after chilling were observed in Slaughterhouse 1 in which an increase in concentrations was observed after evisceration. The effect of processing on Campylobacter and E. coli concentrations in Slaughterhouse 1 did not differ between batches. In Slaughterhouse 2, the effect of processing on the concentrations of both bacteria varied over batches. Changes in E. coli concentration levels during processing were similar to Campylobacter except for defeathering. E. coli concentration significantly decreased after defeathering in both slaughterhouses, whereas Campylobacter increased in Slaughterhouse 2 and in Slaughterhouse 1 no significant changes were observed. The patterns of increases and decreases in bacterial concentrations during processing are specific for each slaughterhouse. Inhomogeneous patterns potentially explain the differences in concentrations after chilling between slaughterhouses. Critical processing steps should be validated in each slaughterhouse by longitudinal studies and potentially based on E. coli. E. coli has a potential to be used as an indicator of processing hygiene, because the impact of most of the studied processing steps was similar as for Campylobacter.

Thermotolerant Campylobacter during Broiler Rearing: Risk Factors and Intervention

Thermotolerant Campylobacters are one of the most important bacterial causative agents of human gastrointestinal illness worldwide. In most European Union (EU) member states human campylobacteriosis is mainly caused by infection with Campylobacter jejuni or Campylobacter coli following consumption or inadequate handling of Campylobacter-contaminated poultry meat. To date, no effective strategy to control Campylobacter colonization of broilers during rearing is available. In this review, we describe the public health problem posed by Campylobacter presence in broilers and list and critically review all currently known measures that have been researched to lower the numbers of Campylobacter bacteria in broilers during rearing. We also discuss the most promising measures and which measures should be investigated further. We end this review by elaborating on readily usable measures to lower Campylobacter introduction and Campylobacter numbers in a broiler flock.

Microbiological criteria for Campylobacter in broiler carcasses in Italy: a possible approach to derive them

The aim of this paper was to provide suitable microbiological criteria (MC) for Campylobacter in broiler carcasses and a sampling plan to verify compliance with such criteria. Data were gathered in the presence and concentration of Campylobacter in broiler carcasses collected in three different Italian slaughterhouses, labelled as A, B and C. The sampling plan to be validated in each slaughterhouse included the analysis of three different carcasses collected immediately after chilling from 30 different lots, for a total of 90 samples per slaughterhouse. The number of positive samples containing above 100 CFU/g and above 1,000 CFU/g throughout the 30 tested lots was determined to estimate between-lot variability. Based on this information, the performance of four MC was evaluated for lot compliance: i) n=3; c=0; m=100 CFU/g; ii) n=3; c=0; m=1,000 CFU/g; iii) n=3; c=1; m=1,000 CFU/g and iv) n=3; c=2; m=1,000 CFU/g. Positive Campylobacter samples were found in 60% of the lots tested in slaughterhouses A and C and in 73.3% of lots from slaughterhouse B. The differences among the three slaughterhouses in the mean Campylobacter levels found in positive samples were not significant and were used to evaluate the performance of the MC. The level of lot compliance to different MC was calculated and for the most stringent one (n=3; c=0; m=100 CFU/g) was 40% at slaughterhouses A and C but only 26.7% at slaughterhouse B. The results of this study show an alternative approach to establish MC for Campylobacter in broilers. According to (1) Campylobacter prevalence and concentration in Italy, (2) applied experimental plan and (3) selected slaughterhouses, the number of compliant lots to the suggested MC ranged between 26.7 and 100%. The selection of the fit for purpose MC is a risk manager decision, based on a reasonable balance between public health and cost for poultry industries.

Preventing Campylobacter at the source: why is it so difficult?

Campylobacteriosis in humans, caused by Campylobacter jejuni and Campylobacter coli, is the most common recognized bacterial zoonosis in the European Union and the United States. The acute phase is characterized by gastrointestinal symptoms. The long-term sequelae (Guillain-Barré syndrome, reactive arthritis, and postinfectious irritable bowel syndrome) contribute considerably to the disease burden. Attribution studies identified poultry as the reservoir responsible for up to 80% of the human Campylobacter infections. In the European Union, an estimated 30% of the human infections are associated with consumption and preparation of poultry meat. Until now, interventions in the poultry meat production chain have not been effectively introduced except for targeted interventions in Iceland and New Zealand. Intervention measures (eg, biosecurity) have limited effect or are hampered by economic aspects or consumer acceptance. In the future, a multilevel approach should be followed, aiming at reducing the level of contamination of consumer products rather than complete absence of Campylobacter.

Prevalence, quantitative load, and antimicrobial resistance of Campylobacter spp. from broiler ceca and broiler skin samples in Thailand

This study was conducted to determine the prevalence of Campylobacter spp. in broiler flocks by testing cecal contents at slaughter and to detect and quantify Campylobacter on broiler carcass skin samples of the corresponding slaughter batches, to determine antimicrobial resistance patterns of the Campylobacter isolates, and to genotype selected Campylobacter jejuni isolates using multilocus sequence typing analysis. Ninety-eight broiler flocks were included in the study. Intact ceca were randomly taken at the time of evisceration throughout a slaughter batch to detect Campylobacter spp. at the broiler flock level and one whole carcass per slaughter batch was taken for the detection of Campylobacter spp. on broiler skin. The prevalences of Campylobacter spp. in broiler ceca and broiler skin samples were 11.2% (11/98) and 51% (50/98), respectively. Even though most Campylobacter-positive broiler skin samples were contaminated with only up to 230 most probable number per gram, a substantial share (13.3%) showed very high Campylobacter numbers on the broiler skin samples (most probable number = ∞; lower confidence limit T(0) 580/g). From 32 C. jejuni and Campylobacter coli isolates tested, the highest antimicrobial resistance rates were found for ciprofloxacin (81.2%), followed by tetracycline (40.6%), ampicillin (31.2%), and erythromycin (9.4%). All tested strains were sensitive to gentamicin. By multilocus sequence typing analysis, a total of 9 different sequence types were identified among 16 C. jejuni isolates. Campylobacter jejuni isolated from cecal content and carcass skin of the same farm or slaughter batch showed corresponding allelic profiles. Our data suggest that intense cross-contamination during the slaughter process led to a strong increase of Campylobacter prevalence on broiler skin compared with the prevalence in broiler ceca. To reduce Campylobacter prevalences on broiler skin, on-farm biosecurity measures need to be accompanied by control measures at the slaughterhouse to reduce fecal contamination of broiler skin and to minimize cross-contamination.

Campylobacter contamination and the relative risk of illness from organic broiler meat in comparison with conventional broiler meat

Danish organic broiler meat, represented by carcasses sampled at the end of processing after chilling, was more frequently contaminated with thermotolerant Campylobacter spp. than conventional broiler carcasses; the yearly mean prevalence being 54.2% (CI: 40.9-67.5) for organic and 19.7% (CI: 14.8-24.7) for conventional carcasses. Campylobacter jejuni was the most frequently isolated species. The difference in prevalence was obvious in all quarters of the year. Contamination of organic and conventional broiler carcasses was more likely to occur in the warmer summer months, in this case in the third quarter, as also documented for conventional broiler flocks. When contaminated, the mean concentration of Campylobacter on neck skin samples of organic and conventional carcasses was not significantly different (P=0.428); 2.0±0.65 log 10 cfu/g and 2.1±0.93 log 10 cfu/g, respectively. Assessing the relative risk of becoming ill following exposure to Campylobacter on conventional or organic broiler meat indicated that the risk per serving from organic carcasses was 1.7 times higher than that of conventional carcasses. The higher risk of illness from organic broiler carcasses compared with conventional broiler carcasses emphasizes the importance of implementing control measures in organic broiler production.