Open Collections

Tong, Shanwei

University of British Columbia

Background: Campylobacter is a leading cause of human gastroenteritis worldwide and is commonly found in poultry products. Campylobacteriosis is the most commonly reported gastrointestinal disease in British Columbia (BC). A high contamination rate of Campylobacter in retail poultry products was previously identified in BC, raising awareness for the control of this foodborne pathogen in the local food production chain. Objective: We hypothesize that the chicken abattoir is a common contamination source for chicken broiler meat. To identify and control the spread of Campylobacter in the abattoir, we carried out environmental sampling inside a local chicken abattoir for 12 weeks (Aug 5th – Sep 9th, Nov 2nd – Dec 7th). Samples were collected in a daily basis. Results: We harvested 324 Campylobacter isolates (268 C. jejuni and 56 C. coli). Whole genome sequencing (WGS) revealed a diverse and fast-shifting Campylobacter population in the abattoir environment throughout the 12 weeks. Certain lineages recur at different time points. Some of the reappearances are likely the result of multiple colonization events, rather than the result of Campylobacter persistence, which was previously thought. In particular, one ST1629 lineage of C. coli was identified five times in this study, ranging from August to December. In addition, point mutations and horizontal gene transfer were commonly identified among isolates of the same lineage. In some lineages, horizontal gene transfer separated highly similar genomes into subpopulations. Conclusions: Contradicting previous studies using traditional genotyping methods, this study found Campylobacter unlikely to persist over 7 days in the abattoir environment, likely reflecting an effective sterilization measure in the abattoir. Benefitting from the high sensitivity of WGS, this study found in numerous occasions that sequence types cannot represent a single lineage. The reappearing lineages suggest the existence of Campylobacter circulation in the BC poultry production chain, which marks the importance of pathogen tracing studies in the broiler farms to further determine its source.

Text

2024-09-30

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/85720

Bioinformatics

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/