Commercial farmed swine harbour a variety of pathogenic bacteria and antimicrobial resistance genes

Abstract

Introduction. The northern region of Thailand serves as a crucial area for swine production, contributing to the Thai community food supply. Previous studies have highlighted the presence of foodborne bacterial pathogens originating from swine farms in this region, posing a threat to both human and animal health. Gap statement. Multiple swine bacterial pathogens have been studied at a species level, but the distribution and co-occurrence of bacterial pathogens in agricultural swine has not been well established. Aim. Our study employed the intestinal scraping technique to directly examine the bacterial micro-organisms interacting with the swine host. Methodology. We used shotgun metagenomic sequencing to analyse the bacterial pathogens inhabiting the caecal microbiome of swine from five commercial farms in northern Thailand. Results. A variety of pathogenic and opportunistic bacteria were identified, including Escherichia coli , Clostridium botulinum , Staphylococcus aureus and the Corynebacterium genus. From a One Health perspective, these species are important foodborne and opportunistic pathogens in both humans and agricultural animals, making swine a critical pathogen reservoir that can cause illness in humans, especially farm workers. Additionally, the swine caecal microbiome contains commensal bacteria such as Bifidobacterium , Lactobacillus and Faecalibacterium , which are associated with normal physiology and feed utilization in healthy swine. Antimicrobial resistance genes were also detected in all samples, specifically conferring resistance to tetracycline and aminoglycosides, which have historically been used extensively in swine farming. Conclusion. The findings further support the need for improved sanitation standards in swine farms, and additional monitoring of agricultural animals and farm workers to reduce contamination and improved produce safety for human consumption.