Prevalence and antimicrobial resistance of Campylobacter isolates from beef cattle and pigs in Japan

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.

First study in the frequency of isolation and phenotypic antimicrobial resistance profiles of pig and cattle origin Campylobacter strains in Romania

Campylobacter spp. is recognized as one of the most common pathogens involved in the development of gastrointestinal infections in humans. The current study aimed to enhance the knowledge on the occurrence and molecular characterization of Campylobacter spp. in pigs and cattle origin caecum samples (n = 56) collected in one year, from nine Romanian slaughterhouses, and to determine the antimicrobial resistance profile of the isolated strains. All Campylobacter spp. strains (n = 41) isolated from swine and cattle caecum samples were analyzed in terms of antimicrobial resistance, in accordance with the EURL protocol and with the Commission Implementing Decision No. 2020/1729. The prevalence rate for C. coli. in pig caecum samples was 92.3% (36/39), and the prevalence of C. jejuni, in cattle origin samples was 29.4% (5/17). C. coli strains isolated from pigs proved resistant to tetracycline 75% (27/36), ciprofloxacin 69.4% (25/36), erythromycin 8.3% (3/36), ertapenem 2.8% (1/36) and gentamicin 2.8% (1/36), but no resistance was observed towards chloramphenicol. C. jejuni strains originating from cattle expressed resistance to ciprofloxacin 60.0% (3/5) and tetracycline 20.0% (1/5), but they were susceptible to chloramphenicol, erythromycin, ertapenem and gentamicin. In the present study, 19.5% (7/36) C. coli strains isolated from pigs were identified as multidrug-resistant (MDR) bacteria. The obtained results demonstrated that pigs especially, but cattle to, can be considered important natural reservoirs for zoonotic multidrug-resistant Campylobacter strains, having a stimulating effect for further studies aiming at the molecular screening of the genotypic antimicrobial resistance processing of a higher number of samples.

Antimicrobial Resistance of Campylobacter coli Isolated from Caecal Samples of Fattening Pigs at Slaughter

Pigs are known as the main Campylobacter coli reservoirs. Campylobacteriosis, the most commonly reported gastrointestinal disease in humans, is mainly caused by the consumption of poultry meat, and little is known about the role of pork. Pigs are often associated with C. coli, including antimicrobial-resistant isolates. Therefore, the entire pork production chain must be considered as an important source of antimicrobial-resistant C. coli. This study aimed to determine the antimicrobial resistance of Campylobacter spp. isolated from caecal samples of fattening pigs at the Estonian slaughterhouse level over a five-year period. The proportion of Campylobacter-positive caecal samples was 52%. All Campylobacter isolates were identified as C. coli. A high proportion of the isolates were resistant to most of the studied antimicrobials. The resistance to streptomycin, tetracycline, ciprofloxacin and nalidixic acid was 74.8%, 54.4%, 34.4% and 31.9%, respectively. In addition, a high proportion (15.1%) of the isolates were multidrug-resistant and, in total, 93.3% were resistant to at least one antimicrobial.

Prevalence and fluoroquinolone resistance of Campylobacter spp. isolated from beef cattle in Japan

Beef is a source of human Campylobacter infections. Antimicrobial treatment is needed when patients are immunocompromised or have other comorbidities. Therefore, we investigated the prevalence and antimicrobial resistance of Campylobacter spp. in beef cattle in Japan. Rectal swab samples were collected from 164 beef cattle at an abattoir between March 2021 and August 2021, and Campylobacter spp. were isolated from 94 (57.3%) cattle. C. jejuni and C. coli were isolated from 68 and 26 cattle, respectively. For Campylobacter jejuni, the resistant rates against ampicillin, tetracycline and ciprofloxacin were 20.6, 75.0 and 64.7%, respectively. For C. coli, the resistant rates against ampicillin, tetracycline and ciprofloxacin were 53.8, 76.9 and 88.5%, respectively. No Campylobacter isolates were resistant to erythromycin. By multilocus sequence typing, C. jejuni and C. coli isolates were classified into 22 and 2 sequence types (STs). The top three STs of C. jejuni were ST806 (12 isolates), ST21 (nine isolates), and ST459 (eight isolates). The most frequent ST of C. coli was ST1068 (23 isolates). The results suggest that Campylobacter spp. are prevalent in the gastrointestinal tract of beef cattle slaughtered at abattoirs. Furthermore, the administration of erythromycin is effective against human campylobacteriosis caused by beef consumption. Monitoring the prevalence and antimicrobial resistance of Campylobacter spp. in beef cattle could be useful for managing the risk of human campylobacteriosis.

Campylobacter jejuni and Other Emerging Campylobacteraceae in Retail Beef Liver - An Underestimated Potential Source?

Bovine by-products, such as liver, could be an underestimated source of Campylobacter jejuni. Therefore, our aims were to evaluate the occurrence of C. jejuni and other Campylobacteraceae in retail beef liver and characterize their antibiotic resistance (ciprofloxacin, tetracycline, erythromycin, and gentamicin) and potential genetic relationship by flagellin gene Restriction Fragment Length Polymorphism (flaA-RFLP) and Multilocus Sequence Typing (MLST) with clinical strains. Seventy-six out of 206 samples (36.9%) were positive for Campylobacter and related organisms. Arcobacter butzleri was the most frequently isolated species (21.8%), followed by C. jejuni (9.7%), C. fetus (7.8%) and C. coli (1%). The C. jejuni strains showed resistance to tetracycline (17.2%) or ciprofloxacin (6.9%), with only one strain resistant to both antibiotics. Meanwhile, 8.3% of ciprofloxacin resistance was observed in C. fetus. The other species showed no resistance. Most of the clonal complexes (CC) in which the C. jejuni genotypes were grouped (CC-21, 42, 48 and 52), coincided with genotypes of clinical strains previously reported in Chile. As such, this study provides evidence that beef liver could be an underestimated route for resistant C. jejuni to humans. Further studies should assess whether this food could play a role in the transmission of other emerging Campylobacteraceae such as those reported here.

Characterization of Campylobacter jejuni in large-billed crows (Corvus macrorhynchos) in Tochigi prefecture, Japan

As free-living crows are a potential source of Campylobacter infections in broilers and cattle, we characterized Campylobacter spp. isolated from crows using multilocus sequence typing and antimicrobial susceptibility testing. We obtained 82 samples from 27 birds captured at seven different times using a trap set in Tochigi prefecture, Japan. Campylobacter jejuni was isolated from 55 (67.1%) of the 82 samples and classified into 29 sequence types, of which 21 were novel. Tetracycline and streptomycin resistance rates were 18.2% and 3.6%, respectively. These results show that most types of C. jejuni infecting crows differ from those isolated from humans, broilers, and cattle. Thus, the importance of free-living crows as reservoirs of Campylobacter infections in broilers and cattle may be limited.

[Prevalence of Foodborne Pathogens in Retail Meat in Saitama, Japan]

We investigated the prevalence of Campylobacter jejuni, Campylobacter coli, Salmonella, enterohemorrhagic Escherichia coli, enterotoxigenic Escherichia coli, Yersinia enterocolitica, and Escherichia albertii in domestic chicken and pork sold at retail stores in Saitama Prefecture, Japan. Campylobacter was detected in 35.7% (60/168) of chicken samples and 7.3% (14/190) of pork samples. C. jejuni and C. coli were predominant in chicken and pork, respectively. Salmonella was found in 58.1% (100/172) of chicken samples and 19.9% (41/206) of pork samples. Moreover, Salmonella Schwarzengrund was the major serovar observed in chicken isolates, whereas S. Typhimurium monophasic variant was in pork isolates. Furthermore, ETEC was found in 0.6% (1/160) of chicken samples and 2.4% (5/206) of pork samples. Y. enterocolitica was absent from all (83/83) chicken samples but was present in 9.3% (18/193) of pork samples, with a prevalence in pork tongues as high as 21.0% (13/62 samples). However, EHEC and E. albertii were not detected in our study. Therefore, the results of this study indicate that chicken was highly contaminated with Campylobacter sp. and Salmonella, and pork was with Y. enterocolitica serotype O3, Campylobacter sp., Salmonella, and ETEC.

Characterization and antimicrobial resistance of Campylobacter jejuni and Campylobacter coli isolated from chicken and pork

The prevalence and antimicrobial resistance (AMR) profile were investigated in Campylobacter jejuni and Campylobacter coli in chicken and pork in Fukuoka, Japan in 2019. Their AMR profiles were compared with those of C. jejuni and C. coli strains isolated in 2013. A total of 53 chicken and 14 pork samples were collected from different supermarkets in Fukuoka in 2019. Campylobacter spp. were isolated by conventional method and characterized by PCR and MALDI-TOF MS. Among 53 chicken samples tested in 2019, 24.5% and 5.7% were positive for C. jejuni and C. coli, respectively, and three (21.4%) of 14 pork samples were positive for C. coli, but not C. jejuni. From the positive samples, 13 and six strains of C. jejuni and C. coli were isolated, respectively. Antimicrobial susceptibility test against 12 different antimicrobials were performed on 48 isolates (43 C. jejuni and five C. coli) from chicken in 2013 and 19 isolates (13 C. jejuni from chicken, three C. coli from chicken and three C. coli from pork) in 2019 using the disk diffusion method. All the C. jejuni and C. coli isolated in 2013 and 2019 were highly resistant to cefazolin and sulfamethoxazole/trimethoprim. Among the C. jejuni isolates from chickens, 25.6% of 2013 isolates were resistant to nalidixic acid, ciprofloxacin, and levofloxacin, and 7% to ampicillin and minocycline, while 30.8% of the isolates were resistant to minocycline, 23.1% to nalidixic acid, ciprofloxacin, and levofloxacin, and 15.4% to ampicillin in 2019. Among the C. coli isolates, 80% of isolates from chickens in 2013, and 33.3% from chicken and 100% from pork in 2019 were resistant to nalidixic acid, ciprofloxacin, and levofloxacin. The frequency of multi-drug resistant (MDR) C. jejuni and C. coli strains from chickens in 2019 were 30.8% and 33.3%, respectively, which were lower than those isolated in 2013 (37.2% and 100%, respectively). One C. jejuni and two C. coli isolates from 2013 were resistant to six antibiotics. However, two C. jejuni and one C. coli isolate from chickens in 2019 were resistant to seven and five antibiotics, respectively. All the C. coli isolates from pork in 2019 were resistant to five antibiotics. The high frequency of AMR strains in C. coli isolates from pork suggests that appropriate use of antimicrobials is required in swine husbandry.

Antibiotic Resistance Profiles and Molecular Mechanisms of Campylobacter From Chicken and Pig in China

The purpose of this research was to characterize the antibiotic resistance profiles of Campylobacter spp. derived from chicken and pig feces collected from farms in Jiangsu Province, China, and to analyze the relevant resistance mechanisms among antimicrobial-resistant Campylobacter spp. isolates. Antibiotic susceptibility to nine antibiotic agents was tested with the microdilution method in 93 Campylobacter spp. (45 C. jejuni and 25 C. coli from chickens; 23 C. coli from pigs). High rates of resistance were observed to nalidixic acid (79.6%), erythromycin (75.3%), tetracycline (68.8%), azithromycin (66.7%), ciprofloxacin (64.5%), and gentamicin (35.5%), with a lower resistance rate to florfenicol (8.6%). The prevalence of the tested antibiotic resistance in C. coli was higher than in C. jejuni from chickens. The rate of antimicrobial resistance to ciprofloxacin in C. coli isolates from chickens was 100.0%, and the C. coli isolates from pigs were all resistant to erythromycin (100%). Most of C. jejuni (64.4%) and C. coli (64.5%) isolates displayed multi-drug resistance. All the Campylobacter spp. isolates resistant to fluoroquinolones had the C257T mutation in the gyrA gene. All 64 tetracycline-resistant Campylobacter spp. isolates were positive for the tetO gene. The tetA gene was also amplified in 6.5% of Campylobacter spp. isolates, whereas tetB was not detected among the isolates. The A2075G point mutation in the 23S rRNA gene occurred in 86.1% (62/72) of the macrolides-resistant Campylobacter spp. isolates, and the ermB gene was identified in 49 Campylobacter spp. isolates (30 C. jejuni and 19 C. coli). Amino acid insertions or mutations in the L4 and L22 ribosomal proteins were not linked to macrolide resistance. These results highlight the high prevalence of resistance to multiple antibiotics, particular macrolides, among Campylobacter spp. from chickens and pigs in Jiangsu Province, China, which is probably attributable to the overuse of antimicrobials in chicken and pig production. These findings recommend the more cautious use of critical antimicrobial agents in swine and poultry production. Stringent and continuous surveillance is required to reduce the drug-resistant campylobacteriosis in food animals and humans.

Prevalence of Campylobacter and Salmonella in African food animals and meat: A systematic review and meta-analysis

BACKGROUND

Campylobacter and Salmonella, particularly non-typhoidal Salmonella, are important bacterial enteric pathogens of humans which are often carried asymptomatically in animal reservoirs. Bacterial foodborne infections, including those derived from meat, are associated with illness and death globally but the burden is disproportionately high in Africa. Commercial meat production is increasing and intensifying in many African countries, creating opportunities and threats for food safety.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, we searched six databases for English language studies published through June 2016, that reported Campylobacter or Salmonella carriage or infection prevalence in food animals and contamination prevalence in food animal products from African countries. A random effects meta-analysis and multivariable logistic regression were used to estimate the species-specific prevalence of Salmonella and Campylobacter and assess relationships between sample type and region and the detection or isolation of either pathogen.

RESULTS

Seventy-three studies reporting Campylobacter and 187 studies reporting Salmonella across 27 African countries were represented. Adjusted prevalence calculations estimate Campylobacter detection in 37.7% (95% CI 31.6-44.3) of 11,828 poultry samples; 24.6% (95% CI 18.0-32.7) of 1975 pig samples; 17.8% (95% CI 12.6-24.5) of 2907 goat samples; 12.6% (95% CI 8.4-18.5) of 2382 sheep samples; and 12.3% (95% CI 9.5-15.8) of 6545 cattle samples. Salmonella were detected in 13.9% (95% CI 11.7-16.4) of 25,430 poultry samples; 13.1% (95% CI 9.3-18.3) of 5467 pig samples; 9.3% (95% CI 7.2-12.1) of 2988 camel samples; 5.3% (95% CI 4.0-6.8) of 72,292 cattle samples; 4.8% (95% CI 3.6-6.3) of 11,335 sheep samples; and 3.4% (95% CI 2.2-5.2) of 4904 goat samples. 'External' samples (e.g. hide, feathers) were significantly more likely to be contaminated by both pathogens than 'gut' (e.g. faeces, cloaca) while meat and organs were significantly less likely to be contaminated than gut samples.

CONCLUSIONS

This study demonstrated widespread prevalence of Campylobacter species and Salmonella serovars in African food animals and meat, particularly in samples of poultry and pig origin. Source attribution studies could help ascertain which food animals are contributing to human campylobacteriosis and salmonellosis and direct potential food safety interventions.

Occurrence and Antimicrobial Resistance Profiles of Campylobacter jejuni, Campylobacter coli, and Campylobacter upsaliensis in Beef Cattle on Cow-Calf Operations in South Africa

This study investigated occurrence and antimicrobial resistance profiles of Campylobacter spp. isolates in beef cattle on five cow-calf operations in South Africa. A total of 537 fecal samples from adult beef cattle (n = 435) and rectal swabs from calves (n = 102) were screened for Campylobacter jejuni, Campylobacter coli, and Campylobacter upsaliensis by culture and polymerase chain reaction. Furthermore, 86 Campylobacter spp. isolates including 46 C. jejuni, 24 C. coli, and 16 C. upsaliensis were tested for antimicrobial resistance against a panel of 9 antimicrobials. Overall, Campylobacter spp. was detected in 29.7% of cattle. Among the 158 Campylobacter spp.-positive cattle, 61.8% carried C. jejuni, 25% carried C. coli, and 10% carried C. upsaliensis. Five animals (3.1%) had mixed infections: three cows carried C. jejuni and C. coli concurrently, one cow had both C. jejuni and C. upsaliensis, and one cow harbored C. coli and C. upsaliensis. Antimicrobial resistance profiling among 86 Campylobacter spp. isolates revealed that 52.3% of the isolates were resistant to one or more antimicrobials. Antimicrobial resistance was observed in 46.7% of C. jejuni isolates, 35.6% of C. coli, and 17.8% of C. upsaliensis. Thirty-six percent of isolates were resistant to clindamycin, 19.7% to nalidixic acid, 18.6% to tetracycline, and 17.4% to erythromycin. Lower resistance rates were recorded for azithromycin (8.1%), florfenicol (3.4%), gentamicin (4.8%), and telithromycin and ciprofloxacin (5.8%). Multidrug resistance (MDR) was observed in 32.5% of isolates. Significantly higher levels of MDR were detected among C. jejuni (36.9%) and C. coli (33.3%) isolates in comparison to C. upsaliensis (18.7%). Two main multiresistance patterns were detected: nalidixic acid/clindamycin (17.8%) and tetracycline/clindamycin (14.2%). To the best of our knowledge, this is the first study which has shown that beef cattle on cow-calf operations in South Africa constitute an important reservoir and a potential source of clinically relevant and antimicrobial resistant Campylobacter spp. strains.

Phylogenetic Diversity and Antimicrobial Resistance of Campylobacter coli from Humans and Animals in Japan

The phylogenetic diversity and antimicrobial resistance (AMR) of Campylobacter coli from humans and animals in Japan between 2008 and 2014 were investigated. A total of 338 foodborne campylobacterioses were reported in Osaka, and C. coli was isolated from 38 cases (11.2%). In the present study, 119 C. coli strains (42 from humans, 25 each from poultry, cattle, and swine, and 2 from wild mallard) were examined by multilocus sequence typing (MLST). MLST assigned 36 sequence types (STs), including 14 novel STs; all human strains and 91% of animal strains (70/77) were assigned to the ST-828 clonal complex. The predominant human ST was ST-860 (18/42, 43%), followed by ST-1068 (8/42, 19%); these STs were also predominant in poultry (ST-860, 9/25, 36%) and cattle (ST-1068, 18/25, 72%). ST-1562 was only predominant in swine (11/25, 44.0%). Swine strains showed the greatest resistance to erythromycin (EM; 92.0%), while EM resistance was only found in 2 out of the 42 human strains examined (4.8%). All EM-resistant swine strains (n=15) exhibited a common point mutation in the 23S rRNA sequence (A2085G), and the tetO gene was detected in 22 out of the 23 TET-resistant swine strains. A whole genome sequencing analysis of four representative swine ST-1562 strains revealed abundant AMR-associated gene clusters in their genomes, suggesting horizontal gene transfer events during host adaptation. This is the first study to demonstrate the phylogenetic diversity and AMR profiles of C. coli in Japan. The present results suggest that poultry and cattle are major reservoirs, improving our knowledge on the epidemiological and ecological traits of this pathogen.

Prevalence and Antibiotic Resistance against Tetracycline in Campylobacter jejuni and C. coli in Cattle and Beef Meat from Selangor, Malaysia

Campylobacter is a major foodborne pathogen frequently associated with human bacterial gastroenteritis in the world. This study was conducted to determine the prevalence and antibiotic resistance of Campylobacter spp. in the beef food system in Malaysia. A total of 340 samples consisting of cattle feces (n = 100), beef (n = 120) from wet markets and beef (n = 120) from hypermarkets were analyzed for Campylobacter spp. The overall prevalence of Campylobacter was 17.4%, consisting of 33% in cattle fecal samples, 14.2% in raw beef from wet market and 7.5% in raw beef from the hypermarket. The multiplex-polymerase chain reaction (PCR) identified 55% of the strains as C. jejuni, 26% as C. coli, and 19% as other Campylobacter spp. A high percentage of Campylobacter spp. were resistant to tetracycline (76.9%) and ampicillin (69.2%), whilst low resistance was exhibited to chloramphenicol (7.6%). The MAR Index of Campylobacter isolates from this study ranged from 0.09 to 0.73. The present study indicates the potential public health risk associated with the beef food system, hence stringent surveillance, regulatory measures, and appropriate interventions are required to minimize Campylobacter contamination and prudent antibiotic usage that can ensure consumer safety.

Antimicrobial Resistance and Genotypes of Campylobacter jejuni from Pig and Cattle Carcasses Isolated in Poland During 2009-2016

Between 2009 and 2016, 317 and 529 swabs from cattle and pig carcasses, respectively, were collected all over Poland and tested for the presence of Campylobacter. Among 37 (11.7%) and 161 (30.4%) positive samples, 44 Campylobacter jejuni isolates were detected. A total of 29 different sequence types (STs) and 12 various clonal complexes were identified. Antimicrobial resistance revealed that 17 (38.6%) C. jejuni (10 from cattle and 7 from pig carcasses, respectively) were susceptible to all antimicrobials used in the study, whereas the remaining 27 (61.4%) isolates (12 from cattle and 15 from pigs, respectively) were resistant to at least one antimicrobial agent, mainly to quinolones (23 out of 44 isolates; 52.3%) and tetracyclines (14 strains; 31.8%). Only one isolate from cattle and two from pigs displayed resistance to streptomycin, and none of C. jejuni tested was resistant to erythromycin and gentamicin. All isolates with STs, ST356, ST443, ST464, ST658, ST2036, and ST6411, as well as some isolates belonging to ST257 and ST1947, were resistant to quinolones and tetracyclines. The results show that cattle and pigs may be a reservoir of quinolone and tetracycline resistant C. jejuni with STs which were previously isolated from humans with campylobacteriosis.

Campylobacter coli in Organic and Conventional Pig Production in France and Sweden: Prevalence and Antimicrobial Resistance

The purpose of the study was to evaluate and compare the prevalence and antimicrobial resistance of Campylobacter coli in conventional and organic pigs from France and Sweden. Fecal or colon samples were collected at farms or at slaughterhouses and cultured for Campylobacter. The minimum inhibitory concentrations of ciprofloxacin, nalidixic acid, streptomycin, tetracycline, erythromycin, and gentamicin were determined by microdilution for a total of 263 French strains from 114 pigs from 50 different farms and 82 Swedish strains from 144 pigs from 54 different farms. Erythromycin resistant isolates were examined for presence of the emerging rRNA methylase erm(B) gene. The study showed that within the colon samples obtained in each country there was no significant difference in prevalence of Campylobacter between pigs in organic and conventional productions [France: conventional: 43/58 (74%); organic: 43/56 (77%) and Sweden: conventional: 24/36 (67%); organic: 20/36 (56%)]. In France, but not in Sweden, significant differences of percentages of resistant isolates were associated with production type (tetracycline, erythromycin) and the number of resistances was significantly higher for isolates from conventional pigs. In Sweden, the number of resistances of fecal isolates was significantly higher compared to colon isolates. The erm(B) gene was not detected in the 87 erythromycin resistant strains tested.

Meat Safety—I Foodborne Pathogens and Other Biological Issues

This chapter presents information pertinent to foodborne pathogens (bacteria and bacterial toxins, viruses, parasites) and other biological issues (prions) with importance to the safety of meat and meat products. Aspects covered refer mainly to the characteristics of the most important pathogenic organisms, their distribution in the environment, their transmission routes to humans, as well as their epidemiology and association with sporadic or epidemic foodborne illness. Current and emerging challenges to meat safety management also are discussed.

Antimicrobial usage and resistance in beef production

Antimicrobials are critical to contemporary high-intensity beef production. Many different antimicrobials are approved for beef cattle, and are used judiciously for animal welfare, and controversially, to promote growth and feed efficiency. Antimicrobial administration provides a powerful selective pressure that acts on the microbial community, selecting for resistance gene determinants and antimicrobial-resistant bacteria resident in the bovine flora. The bovine microbiota includes many harmless bacteria, but also opportunistic pathogens that may acquire and propagate resistance genes within the microbial community via horizontal gene transfer. Antimicrobial-resistant bovine pathogens can also complicate the prevention and treatment of infectious diseases in beef feedlots, threatening the efficiency of the beef production system. Likewise, the transmission of antimicrobial resistance genes to bovine-associated human pathogens is a potential public health concern. This review outlines current antimicrobial use practices pertaining to beef production, and explores the frequency of antimicrobial resistance in major bovine pathogens. The effect of antimicrobials on the composition of the bovine microbiota is examined, as are the effects on the beef production resistome. Antimicrobial resistance is further explored within the context of the wider beef production continuum, with emphasis on antimicrobial resistance genes in the food chain, and risk to the human population.

Antimicrobial Resistance and Genotypic Diversity of Campylobacter Isolated from Pigs, Dairy, and Beef Cattle in Tanzania

Foodborne Campylobacter infections pose a serious threat to public health worldwide. However, the occurrence and characteristics of Campylobacter in food animals and products remain largely unknown in Tanzania. The objective of this study was to determine the prevalence, antibiotic resistance, and genetic profiles (sequence types, STs) of Campylobacter isolated from feces of pigs and dairy and beef cattle in Tanzania. Overall, 259 (~30%) of 864 samples were positive for Campylobacter spp, which were detected in 32.5, 35.4, and 19.6% of the pig, dairy, and beef cattle samples, respectively. Multiplex PCR analysis identified 64.5 and 29.3% of the Campylobacter isolates as C. coli and C. jejuni, respectively. The majority (91.9%) of the isolates from pig samples were identified as C. coli, while C. jejuni accounted for 65.5% of the isolates from cattle. Antimicrobial susceptibility testing using the disk diffusion assay and the broth microdilution method revealed resistance to: ampicillin (Amp) (70.3% and 75.7%, respectively), gentamicin (Gen) (1.8% and 12.6%), streptomycin (Str) (65.8 and 74.8%), erythromycin (Ery) (41.4 and 48.7%), tetracycline (Tet) (18.9 and 23.4%), and ciprofloxacin (Cip) (14.4 and 7.2%). Resistance to nalidixic acid (Nal) (39.6%), azithromycin (Azm) (13.5%), and chloramphenicol (Chl) (4.5%) was determined using the disk diffusion assay only, while resistance to tylosin (Tyl) (38.7%) was quantified using the broth microdilution method. Multilocus sequence typing of 111 Campylobacter isolates resulted in the identification of 48 STs (26 C. jejuni and 22 C. coli) of which seven were novel (six C. jejuni and one C. coli). Taken together, this study revealed the high prevalence, genetic diversity and antimicrobial resistance of Campylobacter in important food animals in Tanzania, which highlights the urgent need for the surveillance and control of Campylobacter in this country.

Prevalence, Antimicrobial Resistance and Risk Factors for Thermophilic Campylobacter Infections in Symptomatic and Asymptomatic Humans in Tanzania

The genus Campylobacter comprises members known to be a leading cause of foodborne gastrointestinal illness worldwide. A study was conducted to determine the epidemiology and antimicrobial resistance of Campylobacter in humans in Morogoro, Eastern Tanzania. Isolation of Campylobacter from stool specimens adopted the Cape Town protocol. Campylobacter isolates were preliminarily identified by conventional phenotypic tests and subsequently confirmed by matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry and polymerase chain reaction. Antimicrobial resistance testing employed the disc diffusion method. A small proportion of the test isolates was also subjected to agar dilution method. Risk factors for human illness were determined in an unmatched case-control study. Thermophilic Campylobacter were isolated from 11.4% of the screened individuals (n = 1195). The agreement between PCR and MALDI-TOF was perfect (κ = 1.0). Symptomatics and young individuals were infected with higher numbers than asymptomatic and adults, respectively. The majority (84.6%) of the isolates were C. jejuni and the remaining were C. coli. Isolates had highest resistance (95.6%) for colistin sulphate and lowest for ciprofloxacin (22.1%). The rates of resistance for other antibiotics (azithromycin, erythromycin, tetracycline, cephalothin, gentamycin, nalidixic acid, ampicillin, amoxycillin, norfloxacin, chloramphenicol) ranged from 44.1% to 89%. Comparison between disc diffusion and agar dilution methods indicated a good correlation, and the tests were in agreement to each other (κ ≥ 0.75). Human illness was found to be associated with young age and consumption of chicken meat and pre-prepared salad. Our data indicate the presence of antibiotic-resistant thermophilic Campylobacter in humans in the study area. There is a need for routine investigation of the presence of the organisms in gastroenteritis aetiology, including determination of their antibiotic susceptibilities.

Free-living Waterfowl as a Source of Zoonotic Bacteria in a Dense Wild Bird Population Area in Northeastern Spain

Salmonella spp. and Campylobacter spp. are zoonotic bacteria that represent an economic and public health concern worldwide. Due to the difficulty to collect samples from free-living waterfowl, little is known on their importance as a reservoir of zoonotic agents. Thus, a study was conducted to determine the prevalence, genotypic diversity and antimicrobial susceptibility of Salmonella and Campylobacter from waterfowl in Ebro Delta (northeastern Spain), a geographical area with a dense wild bird population. Samples were collected from 318 adult waterfowl belonging to nine fowl species. All the samples were taken during the hunting season from 2008 to 2010. None of the birds were positive for Salmonella, while the overall Campylobacter prevalence was 12.58% (40/318). A much higher Campylobacter coli prevalence than Campylobacter jejuni was found (11.64% versus 0.94%). The species Fulica atra showed the highest Campylobacter prevalence (78.05%). ERIC-PCR of the isolates showed a high diversity of strains. Antimicrobial susceptibility testing of Campylobacter isolates showed that all the isolates were susceptible to the seven antibiotics tested.

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

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

Prevalence of Campylobacter spp., Salmonella spp., Listeria monocytogenes, and hepatitis E virus in swine livers collected at an abattoir

We investigated the prevalence of Campylobacter spp., Salmonella spp., Listeria monocytogenes, and hepatitis E virus (HEV) in swine liver. We collected swine livers from 110 pigs at an abattoir from September 2011 to March 2012 [corrected] . Pathogens were detected in the liver samples of 19 (17.3%) pigs. Campylobacter spp. were isolated from the liver samples of 14 (12.7%) pigs. In 10 of the 14 Campylobacter-positive pigs, bacteria were present in the internal regions of the liver. Salmonella spp. and L. monocytogenes were detected in the liver samples of 5 (4.5%) pigs and 1 (1%) pig, respectively. No HEV was detected in the swine liver samples tested. Regarding antimicrobial resistance in Campylobacter and Salmonella isolates, all isolates, except 1 Campylobacter jejuni isolate, were resistant to 1 or more antimicrobial agent. Campylobacter spp. resistant to erythromycin and/or enrofloxacin were isolated from the liver samples of 9 (8%) pigs. These results suggest that the consuming swine liver without proper heat treatment may increase the risk of foodborne illnesses.