Effect of climatic elements on Campylobacter colonization in broiler flocks reared in southern Japan from 2008 to 2012

Transmission of dominant strains of Campylobacter jejuni and Campylobacter coli between farms and retail stores in Ecuador: Genetic diversity and antimicrobial resistance

Thermotolerant Campylobacter is an important zoonotic pathogen known for causing gastroenteritis in humans, with poultry as its primary reservoir. A total of 468 samples were collected, of which 335 were chicken carcass samples (representing the food component), and 133 were chicken caeca samples (representing the animal component). These samples underwent culture, with colonies examined under a microscope. Species identification was achieved through multiplex PCR. Additionally, antimicrobial susceptibility profiles were determined using the Kirby-Bauer method, testing for sensitivity to gentamicin, ciprofloxacin, tetracycline, and erythromycin. Additionally, 55 C. jejuni (62.5%) and 33 C. coli (37.5%) isolates were selected for whole genome sequencing (WGS). A High prevalence of Campylobacter was observed, with rates of 95.5% (n = 127, CI95%: 92.5% - 98.5%) in the animal component and 72.5% (n = 243, CI95%: 69.9% - 75.1%) in the food component. Specifically, C. jejuni was detected in 33.1% (n = 42) of poultry farms and 38.3% (n = 93) of chicken carcasses, while C. coli was found in 64.6% (n = 82) of poultry farms and 60.5% (n = 147) of chicken carcasses. Antimicrobials with the highest rates of resistance (67%-100%) were ciprofloxacin and tetracycline, in both animal and food component isolates. Erythromycin resistance was notable, ranging from 22% to 33%, with only two C. jejuni isolates from retail were resistant to gentamicin. Furthermore, multidrug resistance was identified in 23% (20 isolates) of the Campylobacter isolates. Genetic analysis revealed the presence of fourteen resistance genes in both C. jejuni and C. coli isolates, including tet(O), blaOXA-460, blaOXA-184, blaOXA-489, blaOXA-193, blaOXA-784, blaOXA-603, aph(3')-IIIa, aad9, aph(2'')-If, aadE-Cc, sat4, and ant(6)-Ia. Additionally, twenty-five plasmids were detected in the 88 Campylobacter isolates examined. Interestingly, most isolates also harbored genes encoding putative virulence factors associated with pathogenicity, invasion, adherence, and production of cytolethal distending toxin (cdt): cheV, cheA, cheW, cheY, flaA, flgR, flaC, flaD, flgB, flgC, ciaB, ciaC. The WGS analysis showed the presence of several cgSTs in both animal and food components, with nine of them widely disseminated between components. Moreover, C. coli and C. jejuni isolates from different sources presented less than 11 single nucleotide polymorphisms (SNPs), suggesting clonality (16 isolates). Further analysis using SNP tree demonstrated widespread distribution of certain C. jejuni and C. coli clones across multiple farms and retail stores. This study presents, for the first-time, insights into the clonality, plasmid diversity, virulence, and antimicrobial resistance (AMR) of thermotolerant Campylobacter strains originating from the Ecuadorian poultry industry. The identification of AMR genes associated with the main antibiotics used in the treatment of campylobacteriosis in humans, highlights the importance of the prudent use of antimicrobials in the poultry industry. Additionally, this research remarks the need for regional studies to understand the epidemiology of this pathogen.

Assessing the Prevalence and Dynamics of Emerging Campylobacterales in Human Stool Samples in Brussels by Filtration Culture

Thermophilic C. jejuni/coli is reported to be the first bacterial cause of gastroenteritis worldwide and the most common zoonosis in Europe. Although non-jejuni/coli Campylobacter sp. are increasingly suspected to be responsible for diarrhoea or to be involved in inflammatory bowel disease, they remain poorly isolated due to their fastidious and non-thermophilic nature. Additionally, they are not targeted by commercial syndromic PCR assays. In this study, we present routine diagnostic results over 6 years (2017-2019 and 2021-2023) of Campylobacter sp. and related species, obtained by optimised culture from 51,065 stools by both 0.65 µm pore filtration on antibiotic-free agar, incubated in an H2-enriched atmosphere at 37 °C (also known as the Cape Town protocol), and the use of selective inhibitory Butzler medium incubated at 42 °C. This allowed the isolation of 16 Campylobacter species, 2 Aliarcobacter species, and 2 Helicobacter species, providing a completely different view of the epidemiology of Campylobacterales, in which C. jejuni/coli represents only 30.0% of all isolates, while C. concisus represents 44.4%. C. ureolyticus, representing only 5.5% of all Campylobacterales pre-COVID-19, represented 20.6% of all strains post-COVID-19 (218% increase; p < 0.05). At the same time, the proportions of C. jejuni, C. coli, and C. concisus decreased by 37, 53, and 28%, respectively (p < 0.05).

A Longitudinal Study on Campylobacter in Conventionally Reared Commercial Broiler Flocks in the United States: Prevalence and Genetic Diversity

Poultry meat contaminated with Campylobacter, a major bacterial cause of foodborne gastroenteritis worldwide, is considered the primary source of human campylobacteriosis. Thus, reduction or elimination of Campylobacter in poultry production will have a significant impact on food safety and public health. Despite the significant progress made over the last decades, many puzzles remain about the epidemiology of Campylobacter on poultry farms, hampering the development of an effective control strategy. This longitudinal study was conducted to determine the prevalence and genetic diversity of Campylobacter in a U.S. commercial broiler production farm system. Cecal contents (15 samples/flock) and boot swabs (3 samples/flock) were collected from approximately 6-wk-old birds from 406 conventional broiler flocks reared in 53 houses on 15 farms (located within a relatively close geographic proximity and managed by the same poultry integrator) for up to eight consecutive production cycles and cultured for Campylobacter. Pulsed-field gel electrophoresis was used to investigate the genetic diversity of the Campylobacter jejuni isolates recovered from the cecal contents. The prevalence of Campylobacter at the farm, house, and flock levels were found to be 93% (14/15), 79% (42/53), and 47% (192/406), respectively. Campylobacter prevalence varied remarkably among different farms and flocks, with some farms or houses testing consistently negative while others being positive all the time over the entire study period. Campylobacter isolation rate changed significantly by sample type (higher by cecal contents vs. boot swabs) and season/production cycle (higher in spring vs. other seasons). The majority (88%; 2364/2675) of the isolates were identified as C. jejuni, and almost all the rest (11%; 303/2675) were Campylobacter coli. Genotyping showed limited diversity within a flock and suggested persistence of some C. jejuni clones over multiple production cycles on the same farm. In conclusion, this study indicated that although Campylobacter prevalence was overall high, there were marked differences in the prevalence among the broiler flocks or farms tested. Future studies aimed at identification of potential risk factors associated with differential Campylobacter status are warranted in order to develop effective on-farm interventions.

Surveillance of Shiga toxin-producing Escherichia coli and Campylobacter spp. in wild Japanese deer (Cervus nippon) and boar (Sus scrofa)

Increasing game meat consumption in Japan requires the dissemination of safety information regarding the presence of human pathogens in game animals. Health information regarding the suitability of these animals as a meat source is not widely available. In this study, we aimed to evaluate the safety of game meat and detect potential human pathogens in wild deer (Cervus nippon) and boar (Sus scrofa) in Japan. Fecal samples from 305 wild deer and 248 boars of Yamaguchi, Kagoshima, and Tochigi prefectures collected monthly for 2 years were examined for the prevalence of Shiga toxin-producing Escherichia coli (STEC) and Campylobacter spp. STEC was isolated from 51 deer consistently throughout the year and from three boars; O-antigen genotype O146, the expression of stx2b, and eaeA absence (n=33) were the major characteristics of our STEC isolates. Other serotypes included the medically important O157, stx2b or stx2c, and eaeA-positive (n=4) and O26, stx1a, and eaeA-positive strains (n=1). Campylobacter spp. were isolated from 17 deer and 31 boars. Campylobacter hyointestinalis was the most common species isolated from 17 deer and 25 boars, whereas Campylobacter lanienae and Campylobacter coli were isolated from three and two boars, respectively. Seasonal trends for the isolation of these bacteria were not significant. This study demonstrates that wild game animals carry human pathogens; therefore, detailed knowledge of the safe handling of game meat is needed to prevent foodborne infections.

Effects of climatic elements on Salmonella contamination in broiler chicken meat in Japan

The effects of climatic elements on Salmonella contamination of chicken meat were investigated. Logistic regression analysis was performed to evaluate the association between Salmonella isolation, for 240 chicken samples purchased from March 2015 to February 2017, and climatic elements, over 65 days of chicken rearing. Salmonella was isolated from 143 samples (59.6%), and the most dominant serovars identified were Infantis (77/240, 32.1%) and Schwarzengrund (56/240, 23.3%). Previous studies have reported S. Schwarzengrund contamination of broiler chickens only in western Japan; however, in the present study, S. Schwarzengrund was also isolated from meat produced in eastern Japan-20% (12/60) in the C prefecture to 36.4% (8/22) in the Y prefecture-suggesting that S. Schwarzengrund-contaminated areas have expanded towards eastern Japan. Air temperature showed a significant negative association with S. Schwarzengrund isolation for chicken meat produced during periods with rising temperature (spring and summer) [odds ratio (OR), 0.894 to 0.935; P<0.01]. Moreover, the risk of S. Schwarzengrund contamination of chicken meat was higher during spring (OR, 3.951; P=0.008) and winter (OR, 4.071; P=0.006) than during summer. Effects of climatic elements and differences in contamination risk across seasons were not observed for any Salmonella serovars and only S. Infantis, which could be attributed to differences in transmission patterns and vehicles among Salmonella serovars. These findings are valuable for understanding the dynamics of S. Schwarzengrund dissemination in broiler farms.