Prevalence and Antimicrobial Susceptibility of Campylobacter spp. in Oklahoma Conventional and Organic Retail Poultry

Comparison of Food Safety Hazards in Pigs and Broilers from Intensive and Extensive Production Systems: A Literature Review

Consumer demand for meat from extensive production (e.g., organic, free-range, and antimicrobial-free) is increasing, partly due to consumers' perception that these types are safer than conventional meats. This review compared food safety hazards (namely, zoonotic parasites, bacterial pathogens, antimicrobial resistance, and chemical hazards) from pigs and broilers raised in intensive and extensive systems in Northern and Western European countries and the United States. Our findings showed that hazard occurrence between livestock production systems varied depending on the hazard. Pigs and broilers from extensive systems showed a higher prevalence of Toxoplasma gondii. Pathogen prevalence in pigs did not appear to be affected by production systems, while no clear conclusion could be drawn for broilers due to conflicting findings. Higher antimicrobial resistance (AMR) prevalence was common in pig and broiler samples from intensive farming, although samples from extensive farming were not free of AMR either. Studies on chemical hazards were limited, showing generally low contaminant levels in both production systems, including persistent organic pollutants, heavy metals, mycotoxins, pesticide residues, and antimicrobial residues. Therefore, more studies on chemical hazards are recommended to fill this data gap. Various factors associated with specific production systems could influence hazard prevalence, e.g., indoor confinement, outdoor access, antimicrobial policy, and slaughtering age. Regardless of the production system, other factors, such as seasonal variation and biosecurity levels, were also important.

A Decade of Antimicrobial Resistance in Human and Animal Campylobacter spp. Isolates

Objectives: Campylobacter spp. remain a leading cause of bacterial gastroenteritis worldwide, with resistance to antibiotics posing significant challenges to treatment and public health. This study examines profiles in antimicrobial resistance (AMR) for Campylobacter isolates from human and animal sources over the past decade. Methods: We conducted a comprehensive review of resistance data from studies spanning ten years, analyzing profiles in resistance to key antibiotics, ciprofloxacin (CIP), tetracycline (TET), erythromycin (ERY), chloramphenicol (CHL), and gentamicin (GEN). Data were collated from various regions to assess global and regional patterns of resistance. Results: The analysis reveals a concerning trend of increasing resistance patterns, particularly to CIP and TET, across multiple regions. While resistance to CHL and GEN remains relatively low, the high prevalence of CIP resistance has significantly compromised treatment options for campylobacteriosis. Discrepancies in resistance patterns were observed between human and animal isolates, with variations across different continents and countries. Notably, resistance to ERY and CHL showed regional variability, reflecting potential differences in antimicrobial usage and management practices. Conclusions: The findings underscore the ongoing challenge of AMR in Campylobacter, highlighting the need for continued surveillance and research. The rising resistance prevalence, coupled with discrepancies in resistance patterns between human and animal isolates, emphasize the importance of a One Health approach to address AMR. Enhanced monitoring, novel treatment strategies, and global cooperation are crucial for mitigating the impact of resistance and ensuring the effective management of Campylobacter-related infections.

Complete genome sequence of plasmid-bearing aerotolerant Campylobacter jejuni strain S2-20 isolated from retail chicken meat

Complete genome sequencing of aerotolerant Campylobacter jejuni strain S2-20 revealed the presence of a chromosome of 1,695,449 bp and a plasmid of 49,741 bp that contains predicted antimicrobial resistance and type IV secretion system genes. The chromosome harbored several putative oxidative stress genes with potential roles in aerotolerance.

Transcriptome Analysis of Campylobacter jejuni and Campylobacter coli during Cold Stress

Campylobacter spp. are known to cause campylobacteriosis, a bacterial disease that remains a public health threat. Campylobacter spp. are prevalent in retail meat and liver products, and the prolonged survival of Campylobacter in the low temperatures needed for storage is a challenge for food safety. In this study, RNA-seq was used for the analysis of the C. coli HC2-48 (Cc48) and C. jejuni OD2-67 (Cj67) transcriptomes at 4 °C in a nutrient-rich medium (chicken juice, CJ) and Mueller-Hinton broth (MHB) for 0 h, 0.5 h, 24 h and 48 h. Differentially expressed genes (DEGs) involved in flagellar assembly were highly impacted by low temperatures (4 °C) in C. coli HC2-48, whereas genes related to the ribosome and ribonucleoprotein complex were modulated for C. jejuni OD2-67 at 4 °C. Most of the DEGs in cells grown at 4 °C in the two medium formulations were not significantly expressed at different incubation times. Although more DEGs were observed in CJ as compared to MHB in both Campylobacter strains, the absence of common genes expressed at all incubation times indicates that the food matrix environment is not the sole determinant of differential expression in Campylobacter spp. at low temperatures.

Circulation of thermophilic Campylobacter in pigeons, turkeys, and humans at live bird markets in Egypt

Live bird markets increase the risk of transmission of zoonotic diseases. Few studies have investigated the potential zoonotic transmission of Campylobacter in Egypt. Therefore, our study was carried out to investigate the presence of Campylobacter species, mainly Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli), in pigeons and turkeys sold at poultry shops. Furthermore, the study aimed to explore the potential occupational risk of Campylobacter infection, mainly among workers at poultry shops. Six hundred (n = 600) samples from various organs were obtained from pigeons and turkeys from live bird shops in the Giza and Asyut provinces in Egypt. Additionally, 100 stool samples were collected from persons working at poultry shops. Circulation of thermophilic Campylobacter in pigeons, turkeys, and humans was investigated based on culture and molecular methods. The rate of detection of Campylobacter species from the samples was significant when the culture method was used alone in comparison to when it was used in combination with mPCR. The prevalence rates of Campylobacter species detected by mPCR were 36% (C. jejuni 20%; C. coli 16%), 28% (C. jejuni 12%; C. coli16%), and 29% (C. jejuni 15%; C. coli 14%) in pigeons, turkeys, and workers, respectively. In pigeons, significant variations in the C. jejuni and C. coli occurrence rates were reported in terms of the intestinal content (15, 4%), liver (4, 13%), and skin (9, 7%), respectively. In turkeys, Campylobacter species were mostly detected in liver samples with a percentage of 19%, followed by the skin (12%), and the intestinal content (8%). In conclusion, Campylobacter species are circulating in poultry farms in Egypt and could represent a hazard for humans. It is recommended that biosecurity measures should be applied to mitigate the occurrence of Campylobacter in poultry farms. Moreover, there is an urgent need to transform live bird markets into chilled poultry markets.

A Systematic Review on the Role of Wildlife as Carriers and Spreaders of Campylobacter spp

Campylobacter spp. are important zoonotic pathogens and can cause one of the main bacterial diarrheal diseases worldwide. Research in the context of infection arising from transmission from other humans and other vertebrates has been extensive. A large fraction of these investigations has focused on domestic animals; however, there are also a number of publications which either totally, or at least in part, consider the role of wild or feral animals as carriers or spreaders of Campylobacter spp. Here, we carry out a systematic review to explore the role played by wild vertebrates as sources of Campylobacter spp. with a compilation of prevalence data for more than 150 species including reptiles, mammals and birds. We found that numerous vertebrate species can act as carriers of Campylobacter species, but we also found that some host specificity may exist, reducing the risk of spread from wildlife to domestic animals or humans.

Campylobacter Colonization and Diversity in Young Turkeys in the Context of Gastrointestinal Distress and Antimicrobial Treatment

Young turkeys are vulnerable to undifferentiated gastrointestinal distress, including "irritable and crabby syndrome" (ICS), which compromises flock performance and is typically treated with a combination of penicillin and gentamicin (P/G). However, the effects of ICS and P/G treatment on Campylobacter remain poorly understood. We investigated the impact of ICS and P/G treatment on Campylobacter levels and diversity in four flocks from three turkey farms. Cecum and jejunum samples were analyzed weekly from day of hatch to week 4-5. All four flocks became colonized with multidrug resistant (MDR) Campylobacter jejuni and C. coli by week 2-3, and two developed ICS. ICS and P/G treatment did not significantly impact total Campylobacter levels or strain genotypes but impacted species and antimicrobial resistance (AMR) profiles. One flock was raised under antibiotic-free (ABF) conditions while another flock at the same farm was raised conventionally. The ABF flock did not develop ICS while its counterpart did. However, Campylobacter strains, AMR profiles and sequence types were generally shared between these two flocks. Our findings suggest that ICS and P/G treatment impacted Campylobacter population dynamics in commercial young turkey flocks, and that ABF flocks may become readily colonized by MDR strains from non-ABF flocks at the same farm.

Production systems and important antimicrobial resistant-pathogenic bacteria in poultry: a review

Economic losses and market constraints caused by bacterial diseases such as colibacillosis due to avian pathogenic Escherichia coli and necrotic enteritis due to Clostridium perfringens remain major problems for poultry producers, despite substantial efforts in prevention and control. Antibiotics have been used not only for the treatment and prevention of such diseases, but also for growth promotion. Consequently, these practices have been linked to the selection and spread of antimicrobial resistant bacteria which constitute a significant global threat to humans, animals, and the environment. To break down the antimicrobial resistance (AMR), poultry producers are restricting the antimicrobial use (AMU) while adopting the antibiotic-free (ABF) and organic production practices to satisfy consumers' demands. However, it is not well understood how ABF and organic poultry production practices influence AMR profiles in the poultry gut microbiome. Various Gram-negative (Salmonella enterica serovars, Campylobacter jejuni/coli, E. coli) and Gram-positive (Enterococcus spp., Staphylococcus spp. and C. perfringens) bacteria harboring multiple AMR determinants have been reported in poultry including organically- and ABF-raised chickens. In this review, we discussed major poultry production systems (conventional, ABF and organic) and their impacts on AMR in some potential pathogenic Gram-negative and Gram-positive bacteria which could allow identifying issues and opportunities to develop efficient and safe production practices in controlling pathogens.

Prevalence, antimicrobial resistance, virulence gene profile and molecular typing of Campylobacter species isolated from poultry meat samples

BACKGROUND

Campylobacter jejuni and Campylobacter coli are the most significant Campylobacter species responsible for severe gastrointestinal disorders. Raw poultry meat is considered a source of Campylobacter transmission to the human population.

OBJECTIVES

The present study was aimed to assess the prevalence rate, antibiotic resistance properties, virulence characters and molecular typing of C. jejuni and C. coli strains isolated from raw poultry meat samples.

METHODS

Three hundred and eighty raw poultry meat samples were collected and analysed for the presence of Campylobacter spp. using the microbial culture. Species identification was done using the Polymerase Chain Reaction. Disk diffusion was developed to assess the antimicrobial resistance pattern of isolates. The distribution of virulence and antimicrobial resistance genes was determined by PCR. Enterobacterial Repetitive Intergenic Consensus-PCR was used for molecular typing.

RESULTS

Campylobacter species were isolated from 6.25% of examined samples. C. jejuni and C. coli contamination rates were found to be 57.44% and 48.14%, respectively. C. jejuni strains harboured the highest resistance rate against serythromycin (42.59%), ampicillin (38.88%), ciprofloxacin (33.33%), chloramphenicol (31.48%) and tetracycline (31.48%). C. coli isolates harboured the highest resistance rate against ampicillin (73.07%), ciprofloxacin (73.07%), erythromycin (65.38%) and chloramphenicol (50%). AadE1 (44.44%), blaOXA-61 (42.59%) and tet(O) (35.18%) were the most commonly detected resistance genes in C. jejuni and cmeB (34.61%) and blaOXA-61 (34.61%) were the most commonly detected among C. coli strains. The most frequent virulence factors among the C. jejuni isolates were flaA (100%), ciaB (100%), racR (83.33%), dnaJ (81.48%), cdtB (81.48%), cdtC (79.62%) and cadF (74.07%). The most frequent virulence factors among the C. coli isolates were flaA (100%), ciaB (100%), pldA (65.38%) and cadF (61.53%).

CONCLUSIONS

The majority of C. jejuni and C. coli strains had more than 80% similarities in their ERIC-PCR pattern, which may show their common source of transmission. The role of goose and quebec meat samples as reservoirs of virulent and antimicrobial resistant Campylobacter spp. was determined.

Coupling of acceptor-substituted diazo compounds and tertiary thioamides: synthesis of enamino carbonyl compounds and their pharmacological evaluation

This paper describes the synthesis of enamino carbonyl compounds by the copper(i)-catalyzed coupling of acceptor-substituted diazo compounds and tertiary thioamides. We plan to use this method to synthesize indolizidine (-)-237D analogs to find α6-selective antismoking agents. Therefore, we also performed in silico α6-nAchRs binding studies of selected products. Compounds with low root-mean-square deviation values showed more favorable binding free energies. We also report preliminary pharmacokinetic data on indolizidine (-)-237D and found it to have weak activity at CYP3A4. In addition, as enamino carbonyl compounds are also known for antimicrobial properties, we screened previously reported and new enamino carbonyl compounds for antibacterial, antimicrobial, and antifungal properties. Eleven compounds showed significant antimicrobial activities.

Alternatives to antibiotics for organic poultry production: types, modes of action and impacts on bird's health and production

The poultry industry contributes significantly to bridging the nutritional gap in many countries because of its meat and eggs products rich in protein and valuable nutrients at a cost less than other animal meat sources. The natural antibiotics alternatives including probiotics, prebiotics, symbiotics, organic acids, essential oils, enzymes, immunostimulants, and phytogenic (phytobiotic) including herbs, botanicals, essential oils, and oleoresins are the most common feed additives that acquire popularity in poultry industry following the ban of antibiotic growth promoters (AGPs). They are commonly used worldwide because of their unique properties and positive impact on poultry production. They can be easily mixed with other feed ingredients, have no tissue residues, improve feed intake, feed gain, feed conversion rate, improve bird immunity, improve digestion, increase nutrients availability as well as absorbability, have antimicrobial effects, do not affect carcass characters, decrease the usage of antibiotics, acts as antioxidants, anti-inflammatory, compete for stress factors and provide healthy organic products for human consumption. Therefore, the current review focuses on a comprehensive description of different natural antibiotic growth promoters' alternatives, the mode of their action, and their impacts on poultry production.

Essential oils and their nanoemulsions as green alternatives to antibiotics in poultry nutrition: a comprehensive review

Increasing market pressure to reduce the use of antibiotics and the Veterinary Feed Directive of 2019 have led to expanded research on alternate antibiotic solutions. This review aimed to assess the benefits of using essential oils (EOs) and their nanoemulsions (NEs) as feed supplements for poultry and their potential use as antibiotic alternatives in organic poultry production. Antibiotics are commonly used to enhance the growth and prevent diseases in poultry animals due to their antimicrobial activities. EOs are a complex mixture of volatile compounds derived from plants and manufactured via various fermentation, extraction, and steam distillation methods. EOs are categorized into 2 groups of compounds: terpenes and phenylpropenes. Differences among various EOs depend on the source plant type, physical and chemical soil conditions, harvest time, plant maturity, drying technology used, storage conditions, and extraction time. EOs can be used for therapeutic purposes in various situations in broiler production as they possess antibacterial, antifungal, antiparasitic, and antiviral activities. Several studies have been conducted using various combinations of EOs or crude extracts of their bioactive compounds to investigate their complexity and applications in organic poultry production. NEs are carrier systems that can be used to overcome the volatile nature of EOs, which is a major factor limiting their application. NEs are being progressively used to improve the bioavailability of the volatile lipophilic components of EOs. This review discusses the use of these nonantibiotic alternatives as antibiotics for poultry feed in organic poultry production.

Wildlife Waterfowl as a Source of Pathogenic Campylobacter Strains

BACKGROUND

The aim of the study was to determine whether free-living birds belonging to game species whose meat is used for human consumption can constitute a reservoir of pathogenic Campylobacter strains, spreading these bacteria to other hosts or directly contributing to human infection.

METHODS

A total of 91 cloacal swabs were taken from different species of wildlife waterfowl to estimate the Campylobacter prevalence, the genetic diversity of the isolates, and the presence of virulence genes and to evaluate the antimicrobial resistance.

RESULTS

The presence of Campylobacter spp. was confirmed in 32.9% of samples. Based on flaA-SVR sequencing, a total of 19 different alleles among the tested Campylobacter isolates were revealed. The virulence genes involved in adhesion were detected at high frequencies among Campylobacter isolates regardless of the host species. The highest resistance was observed for ciprofloxacin. The resistance rates to erythromycin and tetracycline were observed at the same level.

CONCLUSIONS

These results suggest that wildlife waterfowl belonging to game species may constitute a reservoir of Campylobacter, spreading these bacteria to other hosts or directly contributing to human disease. The high distribution of virulence-associated genes among wildlife waterfowl Campylobacter isolates make them potentially able to induce infection in humans.

Reduction in Antimicrobial Use and Resistance to Salmonella, Campylobacter, and Escherichia coli in Broiler Chickens, Canada, 2013-2019

Antimicrobial use contributes to the global rise of antimicrobial resistance (AMR). In 2014, the poultry industry in Canada initiated its Antimicrobial Use Reduction Strategy to mitigate AMR in the poultry sector. We monitored trends in antimicrobial use and AMR of foodborne bacteria (Salmonella, Escherichia coli, and Campylobacter) in broiler chickens during 2013 and 2019. We quantified the effect of antimicrobial use and management factors on AMR by using LASSO regression and generalized mixed-effect models. AMR in broiler chickens declined by 6%–38% after the decrease in prophylactic antimicrobial use. However, the withdrawal of individual compounds, such as cephalosporins and fluoroquinolones, prompted an increase in use of and resistance levels for other drug classes, such as aminoglycosides. Canada’s experience with antimicrobial use reduction illustrates the potential for progressive transitions from conventional antimicrobial-dependent broiler production to more sustainable production with respect to antimicrobial use.

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.

Staphylococcus aureus enhances biofilm formation, aerotolerance, and survival of Campylobacter strains isolated from retail meats

In retail meat products, Campylobacter jejuni, C. coli, and Staphylococcus aureus have been reported in high prevalence. The polymicrobial interaction between Campylobacter and other bacteria could enhance Campylobacter survival during the adverse conditions encountered during retail meat processing and storage. This study was designed to investigate the potential role of S. aureus from retail meats in enhancing the survival of Campylobacter exposed to low temperature, aerobic conditions, and biofilm formation. Results indicated that viable S. aureus cells and filter-sterilized cell-free media obtained from S. aureus prolonged the survival of Campylobacter at low temperature and during aerobic conditions. Biofilm formation of Campylobacter strains was significantly enhanced in the presence of viable S. aureus cells, but the results were inconclusive when extracts from cell-free media were used. In conclusion, the presence of S. aureus cells enhances survivability of Campylobacter strains in adverse conditions such as low temperature and aerobic conditions. Further investigations are warranted to understand the interaction between Campylobacter and S. aureus, and effective intervention strategies are needed to reduce the incidence of both foodborne pathogens in retail meat products.

Mapping foodborne pathogen contamination throughout the conventional and alternative poultry supply chains

Recently, there has been a consumer push for natural and organic food products. This has caused alternative poultry production, such as organic, pasture, and free-range systems, to grow in popularity. Due to the stricter rearing practices of alternative poultry production systems, different types of levels of microbiological risks might be present for these systems when compared to conventional production systems. Both conventional and alternative production systems have complex supply chains that present many different opportunities for flocks of birds or poultry meat to be contaminated with foodborne pathogens. As such, it is important to understand the risks involved during each step of production. The purpose of this review is to detail the potential routes of foodborne pathogen transmission throughout the conventional and alternative supply chains, with a special emphasis on the differences in risk between the two management systems, and to identify gaps in knowledge that could assist, if addressed, in poultry risk-based decision making.

Association of Antimicrobial Resistance in Campylobacter spp. in Broilers and Turkeys with Antimicrobial Use

We investigated trends in antimicrobial resistance (AMR) in Campylobacter jejuni and Campylobacter coli in poultry between 2010 and 2016 in Germany and their association with antimicrobial use. Campylobacter had been isolated from the caeca of broilers and turkeys at slaughter by regional laboratories according to current ISO methods in the framework of a national monitoring program. Isolates were submitted to the National Reference Laboratory for Campylobacter and tested for AMR using broth microdilution methods. Minimum inhibitory concentrations were evaluated according to epidemiological cut-off values. Antimicrobial use (AMU) data from 2014 to 2016 were taken from a government report. AMR was higher in C. coli than in C. jejuni and higher in turkeys than in broilers. AMR was highest to tetracycline and the tested (fluoro)quinolones while it was rare to gentamicin in both bacterial species, infrequent to erythromycin in C. jejuni, and moderate in C. coli. AMR to tetracycline and erythromycin decreased over time while it increased to (fluoro)quinolones. An association of AMU and AMR was observed for resistance to tetracycline and erythromycin, while it was not observed for the aminoglycosides. Resistance to nalidixic acid and ciprofloxacin increased despite a decrease of fluoroquinolone use between 2014 and 2016, indicating that other factors have a strong influence on resistance to (fluoro)quinolones in Campylobacter.

Comparison of Antimicrobial Resistance of Thermophilic Campylobacter Isolates from Conventional and Organic Turkey Meat in Germany

The objective of this study was to compare the prevalence and antimicrobial resistance (AMR) rates of Campylobacter spp. isolated from conventional and organic turkey meat sold at retail in Germany. Samples of conventional (N = 527) and organic (N = 245) fresh turkey meat without skin were collected at retail markets throughout Germany and tested for Campylobacter spp.. Campylobacter isolates were tested for resistance to six antimicrobials (gentamicin, streptomycin, ciprofloxacin, nalidixic acid, erythromycin, and tetracycline) using broth microdilution. Prevalence of Campylobacter spp. was higher in organic (32.7%) than in conventional (19.4%) turkey meat. The proportion of fully susceptible isolates was lower in Campylobacter coli (6.8%) than in Campylobacter jejuni (33.9%) and higher in isolates from organic (38.4%) than from conventional production (17.4%). Overall, resistance rates were the highest to ciprofloxacin, nalidixic acid, and tetracycline. Resistance to erythromycin was only observed in C. coli and resistance to gentamicin was absent. Overall, resistance rates to tetracycline and fluoroquinolones were higher in isolates from conventional (60.9% and 78.9%) than from organic meat (32.9% and 58.9%, respectively). However, this significant difference was only observed for C. jejuni, but not for C. coli. Further studies are needed to identify the reasons for the differences in the association of production type of turkeys with AMR in the different Campylobacter spp. and the critical parameters for the reduction of AMR in Campylobacter from turkey meat.

Prevalence of Salmonella and Campylobacter spp. in Alternative and Conventionally Produced Chicken in the United States: A Systematic Review and Meta-Analysis

ABSTRACT

The burden of foodborne illness linked to the consumption of contaminated broiler meat is high in the United States. With the increase in popularity of alternative poultry rearing and production systems, it is important to identify the differences in food safety risks presented by alternative systems compared with conventional methods. Although many studies have been conducted that surveyed foodborne pathogen prevalence along the broiler supply chain, a systematic overview of all of the results is lacking. In the current study, a systematic review and meta-analysis were conducted to quantify the differences in prevalence of Salmonella and Campylobacter spp. in farm environment, rehang, prechill, postchill, and retail samples between conventional and alternative production systems. A systematic search of Web of Science and PubMed databases was conducted to identify eligible studies. Studies were then evaluated by inclusion criteria, and the included studies were qualitatively and quantitatively analyzed. In total, 137 trials from 72 studies were used in the final meta-analysis. Meta-analysis models were individually constructed for subgroups that were determined by sample type, pathogen, and production type. All subgroups possessed high amounts of heterogeneity (I2 > 75%). For environmental sample subgroups, Campylobacter prevalence was estimated to be 15.8 and 52.8% for conventional and alternative samples, respectively. Similar prevalence estimates for both production types were observed for Salmonella environmental samples and all retail samples. For conventional samples, Campylobacter and Salmonella prevalence was highest in prechill samples followed by rehang and postchill samples, respectively. The results herein will be useful in future quantitative microbial risk assessments for characterizing the differences in foodborne illness risks presented by different broiler production systems.

HIGHLIGHTS

Prevalence, seasonality, and antimicrobial resistance of thermotolerant Campylobacter isolated from broiler farms and slaughterhouses in East Algeria

Aim:

The current study was carried out to determine the prevalence, seasonality, and antimicrobial profile of thermotolerant Campylobacter isolated from broiler chickens in Batna, East Algeria, from June 2016 to June 2018.

Materials and Methods:

A total of 960 samples, including 480 cloacal swabs, 240 cecal contents, and 240 neck skin samples collected from 6 poultry farms and 12 slaughterhouses, were included in this study. After isolation and identification, susceptibility to seven antimicrobial agents was tested by the disk diffusion method. The seasonality of Campylobacter infection at broiler farms was statistically analyzed.

Results:

The data showed that 65%, 55%, and 70% of the cloacal swab, neck skin, and cecal content samples were contaminated with thermotolerant Campylobacter strains, respectively (p<0.05). Among the isolated campylobacteria, Campylobacter jejuni was the predominant species (73.5%). Sampling season exhibited a significant impact on the prevalence of Campylobacter (p<0.01), with peak occurrence in summer. All of the isolates were susceptible to gentamicin and resistant to ampicillin and amoxicillin/clavulanic acid, while 83.3% of them were resistant to erythromycin. Interestingly, 16 different resistance profiles were noted, with the combination of “ampicillin, amoxicillin/clavulanic acid, chloramphenicol, erythromycin, and tetracycline” being the most common, identified in 20.7% of isolated strains.

Conclusion:

This study demonstrates the presence of a high contamination rate of multidrug-resistant Campylobacter in farms and slaughterhouses in East Algeria. These findings underscore the need to apply strict control measures to avoid any associated public health hazard among Algerian consumers. This initial finding of the contamination of poultry with this zoonotic pathogen in East Algeria suggests the value of periodic comprehensive evaluation of associated disease in poultry as well as in humans in this region.

A Review of Salmonella and Campylobacter in Broiler Meat: Emerging Challenges and Food Safety Measures

Poultry is one of the largest sources of animal-based protein in the United States. Poultry processing has grown from a small local network of plants to nearly 500 plants nationwide. Two of the most persistent bacteria in poultry processing are Salmonella and Campylobacter. It was not until the introduction of Hazard Analysis and Critical Control Point systems in 1996 that major efforts to reduce bacterial contamination were developed. Traditionally, chlorine has been the industry standard for decontaminating chicken meat. However, antimicrobials such as peracetic acid, cetylpyridinium chloride, and acidified sodium chlorite have replaced chlorine as primary antimicrobials. Despite current interventions, the emergence of stress-tolerant and biofilm-forming Salmonella and Campylobacter is of primary concern. In an effort to offset growing tolerance from microbes, novel techniques such as cold plasma treatment, electrostatic spraying, and bacteriophage-based applications have been investigated as alternatives to conventional treatments, while new chemical antimicrobials such as Amplon and sodium ferrate are investigated as well. This review provides an overview of poultry processing in the United States, major microbes in poultry processing, current interventions, emerging issues, and emerging technologies in antimicrobial treatments.

Molecular Epidemiology of Infectious Zoonotic and Livestock Diseases

Zoonotic and livestock diseases are very important globally both in terms of direct impact on human and animal health and in terms of their relationship to the livelihood of farming communities, as they affect income generation and food security and have other, indirect consequences on human lives. More than two-thirds of emerging infectious diseases in humans today are known to be of animal origin. Bacterial, viral, and parasitic infections that originate from animals, including hypervirulent and multidrug-resistant (MDR) bacterial pathogens, such as livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA), invasive nontyphoidal Salmonella of animal origin, hyperviruent Clostridium difficile, and others, are of major significance to public health. Understanding the origin, risk factors, transmission, prevention, and control of such strains has been a challenge for various reasons, particularly due to the transdisciplinary partnership between and among human, environment, and animal health sectors. MDR bacteria greatly complicate the clinical management of human infections. Food animal farms, pets in communities, and veterinary hospital environments are major sources of such infections. However, attributing such infections and pinpointing sources requires highly discriminatory molecular methods as outlined in other parts of this curated series. Genotyping methods, such as multilocus sequence typing, pulsed-field gel electrophoresis, restriction fragment length polymorphism, and several others, have been used to decipher sources of foodborne and other zoonotic infectious diseases. In recent years, whole-genome-sequence-based approaches have been increasingly used for molecular epidemiology of diseases at the interface of humans, animals, and the environment. This part of the series highlights the major zoonotic and foodborne disease issues. *This article is part of a curated collection.

Okoh A. Campylobacteriosis Agents in Meat Carcasses Collected from Two District Municipalities in the Eastern Cape Province, South Africa

Raw meats are sometimes contaminated with Campylobacter species from animal faeces, and meats have repeatedly been implicated in foodborne infections. This study evaluated the prevalence, virulence genes, antimicrobial susceptibility patterns, and resistance gene determinants in Campylobacter species isolated from retailed meat carcasses. A total of 248 raw meat samples were collected from butcheries, supermarkets, and open markets; processed for enrichment in Bolton broth; and incubated at 42 °C for 48 h in 10% CO2. Thereafter, the broths were streaked on modified charcoal cefoperazone deoxycholate agar (mCCDA) plates and incubated at the same conditions and for the same amount of time. After incubation, colonies were isolated and confirmed by Polymerase chain reaction using specific oligonucleotide sequences used for the identification of the genus Campylobacter, species, and their virulence markers. The patterns of antimicrobial resistance profiles of the identified isolates were studied by disk diffusion method against 12 antibiotics, and relevant resistance genes were assessed by PCR. From culture, 845 presumptive Campylobacter isolates were obtained, of which 240 (28.4%) were identified as genus Campylobacter. These were then characterised into four species, of which C. coli had the highest prevalence rate (22.08%), followed by C. jejuni (16.66%) and C. fetus (3.73%). The virulence genes detected included iam (43.14%), cadF (37.25%), cdtB (23.53%), flgR (18.63%), and flaA (1.96%), and some of the isolates co-harboured two to four virulence genes. Of the 12 antibiotics tested, the highest phenotypic resistance displayed by Campylobacter isolates was against clindamycin (100%), and the lowest level of resistance was observed against imipenem (23.33%). The frequency of resistance genes detected included catll (91.78%), tetA (68.82%), gyra (61.76%), ampC (55%), aac(3)-IIa (aacC2)a (40.98%), tetM (38.71%), ermB (18.29%), tetB (12.90%), and tetK (2.15%). There is a high incidence of Campylobacter species in meat carcasses, suggesting these to be a reservoir of campylobacteriosis agents in this community, and as such, consumption of undercooked meats in this community is a potential health risk to consumers.

PA. Review of Antibiotic Resistance, Ecology, Dissemination, and Mitigation in U.S. Broiler Poultry Systems

Since the onset of land application of poultry litter, transportation of microorganisms, antibiotics, and disinfectants to new locations has occurred. While some studies provide evidence that antimicrobial resistance (AMR), an evolutionary phenomenon, could be influenced by animal production systems, other research suggests AMR originates in the environment from non-anthropogenic sources. In addition, AMR impacts the effective prevention and treatment of poultry illnesses and is increasingly a threat to global public health. Therefore, there is a need to understand the dissemination of AMR genes to the environment, particularly those directly relevant to animal health using the One Health Approach. This review focuses on the potential movement of resistance genes to the soil via land application of poultry litter. Additionally, we highlight impacts of AMR on microbial ecology and explore hypotheses explaining gene movement pathways from U.S. broiler operations to the environment. Current approaches for decreasing antibiotic use in U.S. poultry operations are also described in this review.

Antimicrobial resistance genotypes and phenotypes of Campylobacter jejuni isolated in Italy from humans, birds from wild and urban habitats, and poultry

Campylobacter jejuni, a common foodborne zoonotic pathogen, causes gastroenteritis worldwide and is increasingly resistant to antibiotics. We aimed to investigate the antimicrobial resistance (AMR) genotypes of C. jejuni isolated from humans, poultry and birds from wild and urban Italian habitats to identify correlations between phenotypic and genotypic AMR in the isolates. Altogether, 644 C. jejuni isolates from humans (51), poultry (526) and wild- and urban-habitat birds (67) were analysed. The resistance phenotypes of the isolates were determined using the microdilution method with EUCAST breakpoints, and AMR-associated genes and single nucleotide polymorphisms were obtained from a publicly available database. Antimicrobial susceptibility testing showed that C. jejuni isolates from poultry and humans were highly resistant to ciprofloxacin (85.55% and 76.47%, respectively), nalidixic acid (75.48% and 74.51%, respectively) and tetracycline (67.87% and 49.02%, respectively). Fewer isolates from the wild- and urban-habitat birds were resistant to tetracycline (19.40%), fluoroquinolones (13.43%), and quinolone and streptomycin (10.45%). We retrieved seven AMR genes (tet (O), cmeA, cmeB, cmeC, cmeR, blaOXA-61 and blaOXA-184) and gyrA-associated point mutations. Two major B-lactam genes called blaOXA-61 and blaOXA-184 were prevalent at 62.93% and 82.08% in the poultry and the other bird groups, respectively. Strong correlations between genotypic and phenotypic resistance were found for fluoroquinolones and tetracycline. Compared with the farmed chickens, the incidence of AMR in the C. jejuni isolates from the other bird groups was low, confirming that the food-production birds are much more exposed to antimicrobials. The improper and overuse of antibiotics in the human population and in animal husbandry has resulted in an increase in antibiotic-resistant infections, particularly fluoroquinolone resistant ones. Better understanding of the AMR mechanisms in C. jejuni is necessary to develop new strategies for improving AMR programs and provide the most appropriate therapies to human and veterinary populations.

Overlap of Antibiotic Resistant Campylobacter jejuni MLST Genotypes Isolated From Humans, Broiler Products, Dairy Cattle and Wild Birds in Lithuania

Antimicrobial resistance was determined for 341 thermophilic Campylobacter jejuni isolates obtained from human clinical cases (n = 101), broiler products (n = 98), dairy cattle (n = 41) and wild birds (n = 101) with known multilocus sequence types (MLST) in Lithuania. The minimum inhibitory concentration (MIC) values for ciprofloxacin, tetracycline, gentamicin, ceftriaxone and erythromycin were determined with the agar dilution method. MIC values were compared with MLST types to find possible associations among isolation source, sequence type and resistance to antibiotics. The proportions of resistant strains were 94.2% (human), 95% (wild birds), 100% (broiler products) and 100% (dairy cattle) for one of the tested antibiotics. Most frequently, resistance to ciprofloxacin was observed (91.5%), followed by ceftriaxone with 60.4%, and tetracycline (37.8%). However only three C. jejuni strains were resistant to erythromycin (0.9%) and all tested thermophilic Campylobacter strains were sensitive to gentamicin. Most of the examined C. jejuni isolates (80.6%) showed resistance to at least one of three profiles: CIP+AXO (28.1%), TET+CIP+AXO (26.7%) and CIP (25.8%). Statistically significant differences in resistance to tetracycline were found between C. jejuni strains obtained from cattle (85.4%) and broiler products (64.3%) (P < 0.05). The majority (87.1%) of the tested strains from wild birds were resistant to ciprofloxacin (P < 0.05). The results showed that strains of novel ST's showed significantly lower resistance to ceftriaxone (P < 0.05). The ST-21 (CC21) (78.8%) was identified with significantly higher multidrug resistance relatively to other tested ST's in this study. Our results emphasize the high antimicrobial resistance of phylogenetically diverse C. jejuni strains isolated from different sources including specific genotypes of wild bird's strains in Lithuania. The results support the opinion that not only broiler products but cattle and wild birds may be a reservoir of resistant C. jejuni and stipulate a risk of spread or resistant bacteria. There is increasing need for broad surveillance and control measures to track changes and pathways of antimicrobial resistance of C. jejuni in epidemiologically distinct populations.

The Prevalence of Campylobacter spp. in Polish Poultry Meat

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

Examination of unintended consequences of antibiotic use restrictions in food-producing animals: Sub-analysis of a systematic review

Antimicrobial resistance is considered one of the greatest threats to global and public health today. The World Health Organization, the Food and Agriculture Organization, and the World Organisation for Animal Health, known as the Tripartite Collaboration, have called for urgent action. We have previously published a systematic review of 181 studies, demonstrating that interventions that restrict antibiotic use in food-producing animals are associated with a reduction in antibiotic resistant bacterial isolates in both animals and humans. What remains unknown, however, are whether (and what) unintended consequences may arise from such interventions. We therefore undertook a sub-analysis of the original review to address this research question. A total of 47 studies described potential consequences of antibiotic restrictions. There were no consistent trends to suggest clear harm. There may be increased bacterial contamination of food products, the clinical significance of which remains unclear. There is a need for rigorous evaluation of the unintended consequences of antibiotic restrictions in human health, food availability, and economics, given their possible widespread implications.

Intestinal colonization and acute immune response in commercial turkeys following inoculation with Campylobacter jejuni constructs encoding antibiotic-resistance markers

Consumption of contaminated poultry products is one of the main sources of human campylobacteriosis, of which Campylobacter jejuni subsp. jejuni (C. jejuni) is responsible for approximately 90% of the cases. At slaughter, the ceca of commercial chickens and turkeys are the main anatomical site where C. jejuni asymptomatically colonizes. We have previously colonized commercial turkey poults with different isolates of C. jejuni and evaluated different media to best enumerate Campylobacter from intestinal samples, but the host-response is unknown in turkeys. Enumeration of Campylobacter (colony forming units (cfu)/gram of intestinal contents) can be challenging, and can be confounded if animals are colonized with multiple species of Campylobacter. In order to precisely enumerate the C. jejuni isolate used to experimentally colonize turkeys, constructs of C. jejuni (NCTC 11,168) were tagged with different antibiotic resistance markers at the CmeF locus (chloramphenicol (CjCm) or kanamycin (CjK)). We sought to examine the kinetics of intestinal colonization using the antibiotic resistant constructs, and characterize the immune response in cecal tissue of turkeys. In vitro analysis of the tagged antibiotic-resistant constructs demonstrated no changes in motility, morphology, or adherence and invasion of INT-407 cells compared to the parent isolate NCTC 11,168. Two animal experiments were completed to evaluate intestinal colonization by the constructs. In experiment 1, three-week old poults were colonized after oral gavage for 14 days, and CjCm and CjK cfu were recovered from cecal, but not ileal contents. In experiment 2, nine-week old poults were orally inoculated with CjCm, and the abundance of CjCm cfu/g of cecal contents significantly decreased beyond 14 days after inoculation. Significant lesions were detected in CjCm colonized poults at day 2 post-colonization. Using immunohistochemistry, Campylobacter antigen was detected in between cecal villi by day 7 of CjCm colonized poults. Quantitative RT-PCR of CjCm-colonized cecal tissue demonstrated significant down-regulation of IL-1β, IL-10 and IL-13 mRNA, and significant up-regulation of IL-6, IL-8, IL-17 A, IL-22 and IFNγ mRNA on day 2, and for some on day 7 post-colonization. All differentially expressed genes were similar to mock-infected poults by day 14. These data suggest that C. jejuni induced a brief inflammatory response in the cecum of poults that quickly resolved. Results from this study provide valuable insight into host-response and persistent colonization of the turkey cecum. These findings will help to develop and test strategies to promote food safety in commercial turkeys.

Retail liver juices enhance the survivability of Campylobacter jejuni and Campylobacter coli at low temperatures

The high prevalence of Campylobacter spp. in retail liver products was previously reported and has been linked to several outbreaks of campylobacteriosis. The main objective of this study was to investigate the influence of retail liver juices on the survivability of several strains of C. jejuni and C. coli, which were previously isolated from various retail meats at 4 °C. All tested Campylobacter strains showed higher survival in beef liver juice (BLJ) and chicken liver juice (CLJ) as compared to beef and chicken juices (BJ and CJ) or Mueller Hinton broth (MHB) at 4 °C. Overall, C. jejuni strains showed greater survival in retail liver and meat juices as compared to C. coli. CLJ enhanced biofilm formation of most C. coli strains and supported growth in favorable conditions. When diluted, retail liver and meat juices enhanced survival of Campylobacter strains at low temperatures and increased aerotolerance. In conclusion, beef and chicken liver juices enhanced the survival of C. jejuni and C. coli strains at low temperatures, which helps explain the high prevalence of Campylobacter spp. in retail liver products.

Campylobacter coli From Retail Liver and Meat Products Is More Aerotolerant Than Campylobacter jejuni

Aerotolerance in the microaerophilic species Campylobacter was previously reported and could increase bacterial survival and transmission in foods during stressful processing and storage conditions. In this study, 167 Campylobacter isolates (76 C. jejuni and 91 C. coli) were screened for aerotolerance; these strains were previously isolated from retail chicken meat, chicken livers, chicken gizzards, turkey, pork, and beef liver samples. Bacterial cultures were incubated aerobically in Mueller Hinton broth with agitation and viable cell counts were taken at 0, 6, 12, and 24 h. Approximately 47% of the screened Campylobacter isolates were aerotolerant (viable after a 12-h aerobic incubation period), whereas 24% were hyper-aerotolerant (viable after a 24-h aerobic incubation). A greater prevalence of aerotolerant strains (80%) was found among C. coli isolates as compared to C. jejuni isolates (6%). Differences in the oxidative stress response related genes were detected among C. jejuni and C. coli isolates when comparative genomics was used to analyze 17 Whole Genome Sequenced (WGS) strains from our laboratory. Genes encoding putative transcriptional regulator proteins and a catalase-like heme binding protein were found in C. coli genomes, but were absent in the genomes of C. jejuni. PCR screening showed the presence of a catalase-like protein gene in 75% (68/91) of C. coli strains, which was absent in all tested C. jejuni strains. While about 79% (30/38) of the hyper-aerotolerant C. coli strains harbored the catalase-like protein gene, the gene was also present in a number of the aerosensitive strains. The Catalase like protein gene was found to be expressed in both aerobic and microaerobic conditions with a 2-fold higher gene expression detected in aerobic conditions for an aerosensitive strain. However, the exact function of the gene remains unclear and awaits further investigation. In conclusion, aerotolerant Campylobacter strains (especially C. coli) are prevalent in various retail meats. Further studies are needed to investigate whether the genes encoding catalase-like heme binding protein and putative transcriptional regulators in C. coli strains are involved in stress response.

Prevalence, Serotyping, Molecular Typing, and Antimicrobial Resistance of Salmonella Isolated From Conventional and Organic Retail Ground Poultry

Ground poultry is marketed as a healthier alternative to ground beef despite the fact that poultry is a major source of foodborne Salmonella. The objectives of this study were to determine the prevalence of Salmonella in Oklahoma retail ground poultry and to characterize representative isolates by serotyping, antimicrobial resistance, PFGE patterns, and large plasmid profiling. A total of 199 retail ground poultry samples (150 ground turkey and 49 ground chicken) were investigated. The overall prevalence of Salmonella in ground poultry was 41% (82/199), and the incidence in conventional samples (47%, 66/141) was higher than in organic samples (27%, 16/58). The prevalence of Salmonella in organic ground chicken and organic ground turkey was 33% (3/9) and 26% (13/49), respectively. Twenty six Salmonella isolates (19 conventional and 7 organic) were chosen for further characterization. The following six serotypes and number of isolates per serotype were identified as follows: Tennessee, 8; Saintpaul, 4; Senftenberg, 4; Anatum, 4 (one was Anatum_var._15+); Ouakam, 3; and Enteritidis, 3. Resistance to 16 tested antimicrobials was as follows: gentamycin, 100% (26/26); ceftiofur, 100% (26/26); amoxicillin/clavulanic acid, 96% (25/26); streptomycin, 92% (24/26); kanamycin, 88% (23/26); ampicillin, 85% (22/26); cephalothin, 81% (21/26); tetracycline, 35% (9/26); sulfisoxazole, 27% (7/26); nalidixic acid, 15% (4/26); and cefoxitin, 15% (4/26). All isolates were susceptible to amikacin, chloramphenicol, ceftriaxone, and trimethoprim/sulfamethoxazole. All screened isolates were multidrug resistant (MDR) and showed resistance to 4-10 antimicrobials; isolates from organic sources showed resistance to 5-7 antimicrobials. PFGE was successful in clustering the Salmonella isolates into distinct clusters that each represented one serotype. PFGE was also used to investigate the presence of large plasmids using S1 nuclease digestion. A total of 8/26 (31%) Salmonella isolates contained a ∼100 Kb plasmid that was present in all Anatum and Ouakam isolates. In conclusion, the presence of multidrug resistant Salmonella with various serotypes, PFGE profiles, and large plasmids in ground poultry stresses the importance of seeking novel interventions to reduce the risk of this foodborne pathogen. Multidrug resistance (MDR) is considered a high additional risk and continued surveillance at the retail level could minimize the risk for the consumer.

Phylogenetic Relatedness Among Plasmids Harbored by Campylobacter jejuni and Campylobacter coli Isolated From Retail Meats

Campylobacter jejuni and Campylobacter coli are two of the major causes of foodborne illness. In this study, 29 plasmids isolated from 20 retail meat isolates of Campylobacter jejuni and Campylobacter coli were fully-sequenced individually or as a part of a whole genome sequencing approach. The fully-sequenced plasmids ranged in size from 3 to 119 kb. Molecular characterization of the sequenced plasmids was based on pangenomic analysis and types of genes present on these plasmids and similar ones from GenBank. The plasmids were categorized into four different groups. These groups include type-1 that consisted mainly of pTet plasmids with the tetO gene, type-2 plasmids commonly found in C. coli strains, type-3 which has pVir plasmids, and type-4 that consisted mainly of smaller plasmids. The type-2 plasmids were unique, common among C. coli strains, and carried several conjugative transfer genes. The type-2 plasmids were most similar to a plasmid from Helicobacter pullorum. Maximum parsimony analysis and NeighborNet analysis were used to assess the phylogenetic relatedness among the 29 plasmid sequences presented in this study in addition to the other 104 plasmid sequences of Campylobacter species available in GenBank to date. Results from MP analysis revealed multiple lineages among Campylobacter plasmids which was supported by NeighborNet analysis. Clustering of plasmids did not conform to species-specific clades which suggested an intra-species dissemination of plasmids among Campylobacter species. To our knowledge, this is the first extensive phylogenetic analysis of Campylobacter plasmids sequenced to date.

Sources of contamination, prevalence, and antimicrobial resistance of thermophilic Campylobacter isolated from turkeys

AIM

Sources of contamination, prevalence, and antimicrobial susceptibility of thermophilic Campylobacter isolated from turkey samples were determined.

MATERIALS AND METHODS

A total of 300 samples were collected from 3 farms (fecal droppings) and 4 poultry slaughterhouses (neck skins and ceca) located in the middle area of Algeria (Algiers, Boumerdès, and Bouira). After detection, an antibiogram was realized only for slaughterhouses samples.

RESULTS

Samples from cecum (90.0%, 90/100; 95% confidence interval (CI)=84.1-95.9%), fecal dropping (68.0%, 68/100; 95% CI=58.9-77.1%), and neck skin (55.0%, 55/100; 95% CI=45.2-64.8%) were positive for thermophilic Campylobacter (p<0.05). Contamination rate of turkey carcasses was higher in modern slaughterhouse (96.7%) than in traditional slaughterhouses (37.1%) (p<0.05). Isolated strains were resistant to nalidixic acid (NA) (87.5%), tetracycline (TE) (81.3%), ciprofloxacin (CIP) (75.0%), ampicillin (AM) (65.6%), and erythromycin (25.0%) (p<0.05). 96.9% (124/128) of the isolates were multiresistant and 18 drug resistance patterns were registered. The predominant one (43.0%) was AM, NA, CIP, and TE.

CONCLUSIONS

Potential sources of contamination of this fastidious bacterium were noticed in farms and slaughterhouses. Modern slaughterhouse allowed contamination of turkey carcasses more than a traditional slaughterhouse. However, the scalding step could not represent a source of contamination. The most tested strains exhibited resistance to erythromycin and/or CIP. It is worrisome because these molecules are considered as first-choice antibiotics for human campylobacteriosis.

Genetic characterisation of virulence genes associated with adherence, invasion and cytotoxicity in Campylobacter spp. isolated from commercial chickens and human clinical cases

Virulence-associated genes have been recognised and detected in Campylobacter species. The majority of them have been proven to be associated with pathogenicity. This study aimed to detect the presence of virulence genes associated with pathogenicity and responsible for invasion, expression of adherence, colonisation and production of the cytolethal distending toxin (cdt) in Campylobacter jejuni and Campylobacter coli. Commercial chicken faecal samples were randomly sampled from chicken farms within the Durban metropolitan area in South Africa. Furthermore, human clinical Campylobacter spp. isolates were randomly sampled from a private pathology laboratory in South Africa. Out of a total of 100 chicken faecal samples, 78% (n = 78) were positive for Campylobacter growth on modified charcoal cefoperazone deoxycholate and from the random laboratory collection of 100 human clinical isolates, 83% (n = 83) demonstrated positive Campylobacter spp. growth following culturing methods. These samples were screened for the presence of the following virulence genes: cadF, hipO, asp, ciaB, dnaJ, pldA, cdtA, cdtB and cdtC. As expected, the cadF gene was present in 100% of poultry (n = 78) and human clinical isolates (n = 83). Campylobacter jejuni was the main species detected in both poultry and human clinical isolates, whilst C. coli were detected at a significantly lower percentage (p < 0.05). Eight per cent of the C. jejuni from human clinical isolates had all virulence genes that were investigated. Only one C. coli isolate demonstrated the presence of all the virulence genes investigated; however, the pldA virulence gene was detected in 100% of the C. coli isolates in poultry and a high percentage (71%) in human clinical C. coli isolates as well. The detection of cdt genes was found at higher frequency in poultry than human clinical isolates. The high prevalence rates of virulence genes detected in poultry and human clinical isolates demonstrate their significance in the pathogenicity of Campylobacter species.

Complete Genome Sequences of Campylobacter jejuni Strains Isolated from Retail Chicken and Chicken Gizzards

Genome sequences of Campylobacter jejuni FJ3124 and ZP3204 isolated from retail chicken gizzards and Campylobacter jejuni TS1218 isolated from retail chicken showed the presence of 1,694,324-, 1,763,161-, and 1,762,596-bp circular chromosomes, respectively. Campylobacter jejuni ZP3204 and TS1218 harbored large tetracycline resistance plasmids with type IV secretion systems.

Complete Genome Sequences of Plasmid-Bearing Multidrug-Resistant Campylobacter jejuni and Campylobacter coli Strains with Type VI Secretion Systems, Isolated from Retail Turkey and Pork

We report the complete genome sequences of multidrug-resistant Campylobacter jejuni and Campylobacter coli isolated from retail turkey and pork, respectively. The chromosomes of these two isolates contained type VI secretion system genes. The two isolates also harbored large plasmids with antimicrobial resistance genes possibly contributing to their multidrug resistance.

Detection and prevalence of antimicrobial resistance genes in <i>Campylobacter</i> spp. isolated from chickens and humans

Campylobacter spp. are common pathogenic bacteria in both veterinary and human medicine. Infections caused by Campylobacter spp. are usually treated using antibiotics. However, the injudicious use of antibiotics has been proven to spearhead the emergence of antibiotic resistance. The purpose of this study was to detect the prevalence of antibiotic resistance genes in Campylobacter spp. isolated from chickens and human clinical cases in South Africa. One hundred and sixty one isolates of Campylobacter jejuni and Campylobacter coli were collected from chickens and human clinical cases and then screened for the presence of antimicrobial resistance genes. We observed a wide distribution of the tetO gene, which confers resistance to tetracycline. The gyrA genes that are responsible quinolone resistance were also detected. Finally, our study also detected the presence of the bla_OXA-61, which is associated with ampicillin resistance. There was a higher (p < 0.05) prevalence of the studied antimicrobial resistance genes in chicken faeces compared with human clinical isolates. The tetO gene was the most prevalent gene detected, which was isolated at 64% and 68% from human and chicken isolates, respectively. The presence of gyrA genes was significantly (p < 0.05) associated with quinolone resistance. In conclusion, this study demonstrated the presence of gyrA (235 bp), gyrA (270 bp), bla_OXA-61 and tetO antimicrobial resistance genes in C. jejuni and C. coli isolated from chickens and human clinical cases. This indicates that Campylobacter spp. have the potential of resistance to a number of antibiotic classes.

Pathogens of Food Animals: Sources, Characteristics, Human Risk, and Methods of Detection

Pathogens associated with food production (livestock) animals come in many forms causing a multitude of disease for humans. For the purpose of this review, these infectious agents can be divided into three broad categories: those that are associated with bacterial disease, those that are associated with viruses, and those that are parasitic in nature. The goal of this chapter is to provide the reader with an overview of the most common pathogens that cause disease in humans through exposure via the food chain and the consequence of this exposure as well as risk and detection methods. We have also included a collection of unusual pathogens that although rare have still caused disease, and their recognition is warranted in light of emerging and reemerging diseases. These provide the reader an understanding of where the next big outbreak could occur. The influence of the global economy, the movement of people, and food makes understanding production animal-associated disease paramount to being able to address new diseases as they arise.

Complete Genome Sequences of Campylobacter jejuni Strains OD267 and WP2202 Isolated from Retail Chicken Livers and Gizzards Reveal the Presence of Novel 116-Kilobase and 119-Kilobase Megaplasmids with Type VI Secretion Systems

Genome sequences of Campylobacter jejuni strains OD267 and WP2202, isolated from chicken livers and gizzards, showed the presence of novel 116-kb and 119-kb megaplasmids, respectively. The two megaplasmids carry a type VI secretion system and tetracycline resistance genes. These are the largest sequenced Campylobacter plasmids to date.

Prevalence, genotyping and risk factors of thermophilic Campylobacter spreading in organic turkey farms in Germany

BACKGROUND

The need for organic food of animal origin has increased rapidly in recent years. However, effects of organic animal husbandry on food safety have not been rigorously tested especially in meat turkey flocks. This study provides for the first time an overview on the prevalence and genetic diversity of Campylobacter species (spp.) in five organic meat turkey farms located in different regions in Germany, as well as on potential risk factors of bacterial spreading. Thirty cloacal swabs as well as water samples and darkling beetles were collected from each flock and examined for the presence of Campylobacter by conventional and molecular biological methods. The isolates were genotyped by flaA-RFLP.

RESULTS

Campylobacter spp. were detected in cloacal swabs in all 5 turkey flocks with prevalence ranged from 90.0 to 100 %. 13 cloacal swabs collected from birds in farm III and IV were harboured mixed population of thermophilic campylobacters. In total, from 158 Campylobacter isolated from turkeys 89 (56.33 %) were identified as C. coli and 69 (43.76 %) as C. jejuni. Three Campylobacter (2 C. jejuni and 1 C. coli) were detected in drinkers of two farms and 3 C. coli were isolated from darkling beetles of one farm. No Campylobacter were isolated from main water tanks. flaA-RFLP assay showed that turkey farms can harbour more than one genotype. In a single turkey two different genotypes could be detected. The genotypes of campylobacters isolated from water samples or beetles were identical with those isolated from turkeys. No effect was found of some environmental parameters [ammonia concentration (NH3), carbon dioxide concentration (CO2), relative humidity (RH) and air temperature)] on Campylobacter prevalence in organic turkey farms. Additionally, drinking water and darkling beetles might be considered as risk factors for the spreading of Campylobacter in turkey flocks.

CONCLUSIONS

This study highlights the high prevalence and genotypic diversity of Campylobacter spp. isolated from organic turkey flocks. Further research is needed to assess other potential risk factors responsible for bacteria spreading in order to mitigate the spread of Campylobacter in organic turkey flocks by improving biosecurity control measures.

Whole-Genome Sequencing of a Campylobacter jejuni Strain Isolated from Retail Chicken Meat Reveals the Presence of a Megaplasmid with Mu-Like Prophage and Multidrug Resistance Genes

Genome sequencing of Campylobacter jejuni strain T1-21 isolated from retail chicken meat revealed the presence of a chromosome of 1,565,978 bp and a megaplasmid of 82,732 bp that contains Mu-like prophage and multidrug resistance genes. This is the first reported sequence of a Campylobacter megaplasmid >55 kb.