The Prevalence, Counts and MLST Genotypes of Campylobacter in Poultry Meat and Genomic Comparison with Clinical Isolates

Campylobacter control strategies at postharvest level

Campylobacter is highly associated with poultry and frequently causes foodborne illness worldwide. Thus, effective control measures are necessary to reduce or prevent human infections. In this review, Campylobacter control methods applicable at postharvest level for poultry meat during production, storage, and preparation are discussed. Drying and temperature are discussed as general strategies. Traditional strategies such as steaming, freezing, sanitizing, organic acid treatment, and ultraviolet light treatment are also discussed. Recent advances in nanotechnology using antibacterial nanoparticles and natural antimicrobial agents from plants and food byproducts are also discussed. Although advances have been made and there are various methods for preventing Campylobacter contamination, it is still challenging to prevent Campylobacter contamination in raw poultry meats with current methods. In addition, some studies have shown that large strain-to-strain variation in susceptibility to these methods exists. Therefore, more effective methods or approaches need to be developed to substantially reduce human infections caused by Campylobacter.

Campylobacteriosis: A rising threat in foodborne illnesses

Campylobacteriosis is a foodborne illness that is contracted by eating contaminated food, particularly animal products like meat from diseased animals or corpses tainted with harmful germs. The epidemiology of campylobacteriosis varies significantly between low-, middle-, and high-income countries. Campylobacter has a complicated and poorly known survival strategy for getting past host barriers and causing sickness in humans. The adaptability of Campylobacter to unfavorable environments and the host's immune system seems to be one of the most crucial elements of intestinal colonization. A Campylobacter infection may result in fever, nausea, vomiting, and mild to severe bloody diarrhea in humans. Effective and rapid diagnosis of Campylobacter species infections in animal hosts is essential for both individual treatment and disease management at the farm level. According to the most recent meta-analysis research, the main risk factor for campylobacteriosis is travel, which is followed by eating undercooked chicken, being exposed to the environment, and coming into close contact with livestock. Campylobacter jejuni, and occasionally Campylobacter coli, are the primary causes of Campylobacter gastroenteritis, the most significant Campylobacter infection in humans for public health. The best antibiotic medications for eradicating and decreasing Campylobacter in feces are erythromycin, clarithromycin, or azithromycin. The best strategy to reduce the number of human infections caused by Campylobacter is to restrict the amount of contamination of the poultry flock and its products, even if the majority of infections are contracted through handling or ingestion of chicken.

Meta-analyses of the global multilocus genotypes of the human pathogen Campylobacter jejuni

Campylobacter infections are a leading cause of bacterial diarrheal illness worldwide, with increasing reports of outbreaks in both developing and developed countries. Most studies investigating strain genotypes and epidemiology of Campylobacter jejuni examined on a local scale. Using the archived multilocus sequence typing data at seven loci, and associated strain metadata from the PubMLST database, here we investigated the spatial and temporal genetic structure of the global population of C. jejuni. Our analyses revealed evidence for clonal dispersals of multiple sequence types (STs) among countries and continents. However, despite the observed clonal dispersal and that most genetic variations were found within individual geographic subpopulations, both the non-clone-corrected and clone-corrected samples showed evidence of significant genetic differentiation among national and continental subpopulations, with non-clone-corrected samples showing greater differentiation than clone-corrected samples. Phylogenetic incompatibility analyses provided evidence for recombination within each continental subpopulation. However, linkage disequilibrium analyses rejected the hypothesis of random recombination across the samples. Temporally, multiple STs were found to persist across four decades and the five globally most common STs showed relatively stable frequencies over the last two decades. We discussed the implications of our results to food security, disease transmission, and public health management.

Assessing concordance between Campylobacter prevalence in broilers and human cases before and during the COVID-19 pandemic in Lower Saxony, Germany, considering fresh chicken meat consumption patterns

As the most common foodborne disease, number of campylobacteriosis decreased in Germany with the beginning of the COVID-19 pandemic in 2020. As the consumption of fresh chicken meat is a major risk factor for human infection, this study investigated the relationship between Campylobacter contamination levels on chicken carcasses and human cases in Lower Saxony, Germany and observed fresh chicken meat consumption patterns between 2018 and 2021 including the time of the COVID-19 pandemic. Campylobacter levels in broilers and human cases were classified based on the median and descriptively analysed per week using contingency tables. Before the COVID-19 pandemic (2018 and 2019), high Campylobacter contamination levels on neck samples and many human cases were more present, whereas with the beginning of the COVID-19 pandemic (2020 and 2021), low contamination levels on chicken carcasses and few human cases were more present. Lowest concordance between both parameters was shown in 2018 (Cohen's cappa coefficient: 0.37) and 2020 (0.38). The highest concordance was examined in 2021 (0.69). The private consumption of fresh chicken meat in Lower Saxony increased significantly with the beginning of the COVID-19 pandemic in 2020 by 63.9 tonnes compared to 2019 to an average of 453.5 tonnes per week. Public health measures and a reduced number of medical treatments have undoubtedly had an impact on less reported human cases during the COVID-19 pandemic. However, number of human cases remained at a low level in Germany in 2023 while chicken meat consumption increased. Thus, further risk assessments regarding the risk of campyloabcteriosis due to chicken meat consumption should include the country of origin, as the level of contamination of chicken carcasses varies between European countries.

Prevalence of Campylobacter spp., Salmonella spp., and Listeria monocytogenes, and Population Levels of Food Safety Indicator Microorganisms in Retail Raw Chicken Meat and Ready-To-Eat Fresh Leafy Greens Salads Sold in Greece

The presence of microbial pathogens in foods compromises their safety resulting in foodborne illnesses, public health disorders, product recalls, and economic losses. In this work, 60 samples of chilled raw chicken meat and 40 samples of packaged ready-to-eat (RTE) fresh leafy greens salads, sold in Greek retail stores (butchers and supermarkets), were analyzed for the presence of three important foodborne pathogenic bacteria, i.e., Campylobacter spp., Salmonella spp., and Listeria monocytogenes, following the detection protocols of the International Organization for Standardization (ISO). In parallel, the total aerobic plate count (APC), Enterobacteriaceae, total coliforms, Escherichia coli, and staphylococci were also enumerated as hygiene (safety) indicator organisms. When present, representative typical colonies for each pathogen were biochemically verified, following the ISO guidelines. At the same time, all the Campylobacter isolates from chicken (n = 120) were identified to the species level and further phylogenetically discriminated through multiplex and repetitive sequence-based (rep) polymerase chain reaction (PCR) methods, respectively. Concerning raw chicken, Campylobacter spp. were recovered from 54 samples (90.0%) and Salmonella spp. were recovered from 9 samples (15.0%), while L. monocytogenes was present in 35 samples (58.3%). No Campylobacter was recovered from salads, and Salmonella was present in only one sample (2.5%), while three salads were found to be contaminated with L. monocytogenes (7.5%). The 65% of the Campylobacter chicken isolates belonged to C. jejuni, whereas the rest, 35%, belonged to C. coli. Alarmingly, APC was equal to or above 106 CFU/g in 53.3% and 95.0% of chicken and salad samples, respectively, while the populations of some of the other safety indicators were in some cases also high. In sum, this study unravels high occurrence percentages for some pathogenic and food safety indicator microorganisms in raw chicken meat and RTE fresh leafy greens salads sold in Greek retail, highlighting the need for more extensive microbiological control throughout the food production chain (from the farm/field to the market).

Prevalence and genetic characterization of Campylobacter from clinical poultry cases in China

IMPORTANCE

Campylobacter is a major cause of campylobacteriosis worldwide, and poultry is the main reservoir for its transmission. Campylobacter was generally considered to be a harmless commensal organism in poultry without pathogenic properties. However, it was proposed that a Campylobacter-like organism may be the cause of vibrionic hepatitis, which poses a significant public health risk. The occurrence and epidemiology of Campylobacter in healthy poultry have been studied systematically, but little is known about the epidemiology of Campylobacter isolates from diseased poultry in China. Therefore, this study determined the prevalence and molecular characterization of Campylobacter from diseased chickens, ducks, and geese in Yangzhou Veterinary Hospital between December 2016 and September 2017, which was critical for improving the diagnosis and prevention of Campylobacter infections.

Rapid Genotyping of Campylobacter coli Strains from Poultry Meat by PFGE, Sau-PCR, and fla-DGGE

The genotyping of Campylobacter coli was done using three methods, pulsed-field gel electrophoresis (PFGE), Sau-polymerase chain reaction (Sau-PCR), and denaturing gradient gel electrophoresis assay of flagellin gene (fla-DGGE) and the characteristics of these assays were compared. The results showed that a total of 53 strains of C. coli were isolated from chicken and duck samples in three markets. All isolates were clustered into 31, 33, and 15 different patterns with Simpson's index of diversity (SID) values of 0.972, 0.974, and 0.919, respectively. Sau-PCR assay was simpler, more rapid, and had higher discriminatory power than PFGE assay. Fla-DGGE assay could detect and illustrate the number of contamination types of C. jejuni and C. coli without cultivation, which saved more time and cost than Sau-PCR and PFGE assays. Therefore, Sau-PCR and fla-DGGE assays are both rapid, economical, and easy to perform, which have the potential to be promising and accessible for primary laboratories in genotyping C. coli strains.

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.

MLST genotypes and quinolone resistance profiles of Campylobacter jejuni isolates from various sources in Turkey

This study was conducted to determine the overall genetic diversity, as well as prevalence and mechanisms of resistance to quinolone antibiotics of 178 Campylobacter jejuni isolated from humans, cattle, dogs, and chickens in Turkey. Multilocus sequence typing (MLST) and E-test were performed for genotyping and antimicrobial susceptibility testing, respectively. Mismatch Amplification Mutation Assay, Polymerase Chain Reaction (MAMA-PCR) was used to detect point mutations associated with quinolone resistance. Of the 178 isolates tested, 151 were included in 21 clonal complexes (CCs); the remaining 27 isolates did not belong to any existing CCs. CC21, CC353, CC206, and CC257 were the predominant clones, representing 38 % of all C. jejuni isolates tested. The isolates were assigned to 78 different sequence types (STs), three of which were novel (ST 8082, ST 8083, and ST 8084). Resistance to quinolones was found in 73 (41 %) of the isolates (42.85 %, 2.85 %, 20.58 %, and 43.75 % in human, cattle, dog, and chicken isolates, respectively). All of the resistant isolates had Thr-86-Ile mutation in the gyrA gene. The highest Sorensen coefficient index was detected for human/chicken meat and human/dog C. jejuni isolates (Ss = 0.71), suggesting a strong link between the isolates from respective sources. The Simpson diversity index of C. jejuni isolates analyzed was detected between 0.92 and 0.98. The study provides detailed information on the quinolone resistance and MLST-based genetic relatedness of C. jejuni isolates from humans, cattle, dog, and broiler meat in Turkey for the first time, enabling a better understanding of the transmission pathways of C. jejuni in this country. Our results suggest that broiler meat and dogs may be the most important sources of human campylobacteriosis in Turkey.

Prevalence and Characterization of Salmonella Isolated from Chickens in Anhui, China

Salmonella is one of the most important zoonotic pathogens that can cause both acute and chronic illnesses in poultry flocks, and can also be transmitted to humans from infected poultry. The purpose of this study was to investigate the prevalence, antimicrobial resistance, and molecular characteristics of Salmonella isolated from diseased and clinically healthy chickens in Anhui, China. In total, 108 Salmonella isolates (5.66%) were successfully recovered from chicken samples (n = 1908), including pathological tissue (57/408, 13.97%) and cloacal swabs (51/1500, 3.40%), and S. Enteritidis (43.52%), S. Typhimurium (23.15%), and S. Pullorum (10.19%) were the three most prevalent isolates. Salmonella isolates showed high rates of resistance to penicillin (61.11%), tetracyclines (47.22% to tetracycline and 45.37% to doxycycline), and sulfonamides (48.89%), and all isolates were susceptible to imipenem and polymyxin B. In total, 43.52% isolates were multidrug-resistant and had complex antimicrobial resistance patterns. The majority of isolates harbored cat1 (77.78%), blaTEM (61.11%), and blaCMY-2 (63.89%) genes, and the antimicrobial resistance genes in the isolates were significantly positively correlated with their corresponding resistance phenotype. Salmonella isolates carry high rates of virulence genes, with some of these reaching 100% (invA, mgtC, and stn). Fifty-seven isolates (52.78%) were biofilm-producing. The 108 isolates were classified into 12 sequence types (STs), whereby ST11 (43.51%) was the most prevalent, followed by ST19 (20.37%) and ST92 (13.89%). In conclusion, Salmonella infection in chicken flocks is still serious in Anhui Province, and not only causes disease in chickens but might also pose a threat to public health security.

Campylobacter spp. isolated from poultry in Iran: Antibiotic resistance profiles, virulence genes, and molecular mechanisms

Campylobacter spp. genera is one of the most common causes of microbial enteritis worldwide. The objective of this work was to investigate the antimicrobial resistance (AMR) patterns, virulence genes, and genetic variation of thermophilic Campylobacter species collected from chicken meat samples in Iran. A total of 255 meat specimens were taken and transferred to the laboratory. Culture methods were utilized to identify the Campylobacter genus, and PCR and sequencing were performed to confirm the organisms. Antimicrobial susceptibility evaluation was performed using broth microdilution for six antimicrobials [ciprofloxacin (CIP), nalidixic acid (NAL), sitafloxacin (SIT), erythromycin (ERY), tetracycline (TET), and gentamicin (GEN)]. By using PCR, AMR and virulence genes were detected. The detection rate of Campylobacter spp. was 64 (25.09%) out of 255 meat samples, with C. jejuni and C. coli accounting for 41 (64.06%) and 14 (21.87%), respectively. Other Campylobacter isolates accounted for 14.06% of the total (nine samples). The antibiotic susceptibility of all Campylobacter isolates was tested using six antibiotics, and all (100%) were resistant to CIP and NAL. However, TET resistance was observed in 93.9% and 83.3% of C. jejuni and C. coli isolates, respectively. Four (8.2%) C. jejuni isolates were multidrug-resistant (MDR), while none of the C. coli isolates were MDR. Two of the four MDR isolates were resistant to CIP, NAL, TET, and ERY, whereas the other two isolates were resistant to CIP, NAL, TET, and GEN. The values of the Minimum Inhibitory Concentration (MIC) were as follows: CIP, 64-256 μg/ml; NAL, 128-512 μg/ml; TET, 2-1024 μg/ml; SIT, 0.25-1 μg/ml; ERY, 1-32 μg/ml; and GEN, 1-256 μg/ml. recR, dnaJ, cdtC, cdtB, cdtA, flaA, ciaB, cadF, and pidA were discovered in more than 50% of C. jejuni isolates, although wlaN, virbll, cgtB, and ceuE were found in <50%. flaA, cadF, pidA, and ciaB were discovered in more than 50% of the C. coli samples, whereas recR, cdtC, cdtB, cdtA, and cgtB were found in less than half. For C. coli, the percentages for wlaN, dnaJ, virbll, and ceuE were all zero. The results of this study show Campylobacter isolates obtained from poultry have higher resistance to quinolones and TET, pathogenicity potential, and varied genotypes.

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

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

The rise of antibiotic resistance in Campylobacter

PURPOSE OF REVIEW

Campylobacter is a major foodborne pathogen that infects the human intestinal tract. This review discusses the current status of antibiotic resistance, transmission of antibiotic resistance genes, and strategies to combat the global Campylobacter epidemic.

RECENT FINDINGS

Over the past 18 months, articles on Campylobacter antibiotic resistance have been published in ∼39 countries. Antibiotic-resistant Campylobacter have been detected in humans, livestock, poultry, wild animals, the environment, and food. Campylobacter spp. are resistant to a wide spectrum of antimicrobial agents, including the antibiotics quinolones, macrolides, tetracyclines, aminoglycosides, and chloramphenicols. Multidrug resistance is a globally emerging problem. Continuous antibiotic pressure promotes the spread of drug-resistant Campylobacter spp. Additionally, Campylobacter is well adapted to acquiring foreign drug resistance genes, including ermB, optrA, fexA, and cfrC, which are usually acquired from gram-positive bacteria.

SUMMARY

The widespread use of antibiotics has caused a global epidemic of drug-resistant Campylobacter infections. Many countries are actively reducing the use of antibiotics and adopting alternatives in the livestock and poultry industries to control the spread of drug-resistant Campylobacter spp.

Antibiotic Resistance in Campylobacter spp. Isolated from Broiler Chicken Meat and Human Patients in Estonia

Poultry meat is considered the most important source of Campylobacter spp. Because of rising antimicrobial resistance in Campylobacter spp., this study investigated the antimicrobial resistance of Campylobacter isolates from fresh broiler chicken meat originating from the Baltic countries sold in Estonian retail settings. Additionally, human clinical isolates obtained from patients with Campylobacter enteritis in Estonia were analysed. The aim of this study was to investigate the susceptibility of Campylobacter spp. to nalidixic acid, ciprofloxacin, tetracycline, streptomycin, erythromycin and gentamicin. The broth microdilution method with the EUCAMP2 panel was used for MIC determination and antimicrobial mechanisms were analysed using WGS data. A total of 46 Campylobacter strains were analysed, of which 26 (42.6%) originated from Lithuanian, 16 (26.2%) from Latvian, and 4 (6.6%) from Estonian fresh broiler chicken meat. In addition, 15 (24.6%) Campylobacter strains of patients with campylobacteriosis were tested. The antimicrobial resistance patterns of Campylobacter spp. isolated from fresh broiler chicken meat samples of Estonian, Latvian and Lithuanian origin collected in Estonian retail, and from patients with Campylobacter enteric infections, were determined. A total of 46 (75%) of the isolates tested were C. jejuni and 15 (25%) were C. coli. Campylobacter resistance was highest to nalidixic acid (90.2% of strains) and ciprofloxacin (90.2%), followed by tetracycline (57.4%), streptomycin (42.6%) and erythromycin (6.6%). All strains were sensitive to gentamicin. Additionally, antimicrobial resistance genes and point mutations were detected in 27 C. jejuni and 8 C. coli isolates previously assigned as resistant with the phenotypic method. A high antibiotic resistance of Campylobacter spp. in Lithuanian- and Latvian-origin broiler chicken meat and Estonian clinical isolates was found. Similar antibiotic resistance patterns were found for broiler chicken meat and human Campylobacter isolates.