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Dairy Cattle, a Potential Reservoir of Human Campylobacteriosis: Epidemiological and Molecular Characterization of Campylobacter jejuni From Cattle Farms.

ABSTRACT: Campylobacter jejuni is a major foodborne pathogen that is increasingly found worldwide and that is transmitted to humans through meat or dairy products. A detailed understanding of the prevalence and characteristics of C. jejuni in dairy cattle farms, which are likely to become sources of contamination, is imperative and is currently lacking. In this study, a total of 295 dairy cattle farm samples from 15 farms (24 visits) in Korea were collected. C. jejuni prevalence at the farm level was 60% (9/15) and at the animal level was 23.8% (68/266). Using the multivariable generalized estimating equation (GEE) model based on farm-environmental factors, we estimated that a high density of cattle and average environmental temperature (7 days prior to sampling) below 24°C affects the presence and survival of C. jejuni in the farm environment. Cattle isolates, together with C. jejuni from other sources (chicken and human), were genetically characterized based on analysis of 10 virulence and survival genes. A total of 19 virulence profile types were identified, with type 01 carrying eight genes (all except hcp and virB11) being the most prevalent. The prevalence of virB11 and hcp was significantly higher in isolates from cattle than in those from other sources (p < 0.05). Multilocus sequence typing (MLST) of C. jejuni isolates from three different sources mainly clustered in the CC-21 and CC-48. Within the CC-21 and CC-48 clusters, cattle isolates shared an indistinguishable pattern with human isolates according to pulsed-field gel electrophoresis (PFGE) and flaA-restriction fragment length polymorphism (RFLP) typing. This suggests that CC-21 and CC-48 C. jejuni from dairy cattle are genetically related to clinical campylobacteriosis isolates. In conclusion, the farm environment influences the presence and survival of C. jejuni, which may play an important role in cycles of cattle re-infection, and dairy cattle represent potential reservoirs of human campylobacteriosis. Thus, environmental management practices could be implemented on cattle farms to reduce the shedding of C. jejuni from cattle, subsequently reducing the potential risk of the spread of cattle-derived C. jejuni to humans through the food chain.

SUBMITTER: An JU

PROVIDER: S-EPMC6305296 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

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Project description:Foodborne outbreaks caused by Campylobacter jejuni have become a significant public health problem worldwide. Applying genomic sequencing as a routine part of foodborne outbreak investigation remains in its infancy in China. We applied both traditional PFGE profiling and genomic investigation to understand the cause of a foodborne outbreak in Hangzhou in December 2018. A total of 43 fecal samples, including 27 sick patients and 16 canteen employees from a high school in Hangzhou city in Zhejiang province, were recruited. Routine real-time fluorescent PCR assays were used for scanning the potential infectious agents, including viral pathogens (norovirus, rotavirus, adenovirus, and astrovirus), and bacterial pathogens (Salmonella, Shigella, Campylobacter jejuni, Vibrio parahaemolyticus and Vibrio cholerae). Bacterial selection medium was used to isolate and identify the positive bacteria identified by molecular test. Pulsed field gel electrophoresis (PFGE), and next generation sequencing (NGS) were applied to fifteen recovered C. jejuni isolates to further understand the case linkage of this particular outbreak. Additionally, we retrieved reference genomes from the NCBI database and performed a comparative genomics analysis with the examined genomes produced in this study. The analyzed samples were found to be negative for the queried viruses. Additionally, Salmonella, Shigella, Vibrio parahaemolyticus and Vibrio cholera were not detected. Fifteen C. jejuni strains were identified by the real-time PCR assay and bacterial selection medium. These C. jejuni strains were classified into two genetic profiles defined by the PFGE. Out of fifteen C. jejuni strains, fourteen have a unified consistent genotype belonging to ST2988, and the other strain belongs to ST8149, with a 66.7% similarity in comparison with the rest of the strains. Moreover, all fifteen strains harbored blaOXA-61 and tet(O), in addition to a chromosomal mutation in gyrA (T86I). The examined fourteen strains of ST2988 from CC354 clone group have very minimal genetic difference (3~66 SNPs), demonstrated by the phylogenomic investigation. Both genomic investigation and PFGE profiling confirmed that C. jejuni ST2988, a new derivative from CC354, was responsible for the foodborne outbreak Illustrated in this study.

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Dataset Information

Dairy Cattle, a Potential Reservoir of Human Campylobacteriosis: Epidemiological and Molecular Characterization of Campylobacter jejuni From Cattle Farms.

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