This is the author accepted manuscriptIt is well verified that pig farms are an important reservoir and supplier of antibiotic resistance genes (ARGs). However, little is
known about the transmission of ARGs between the breeding environment and subsequently produced pork. This study was
conducted to investigate if ARGs and associated host bacteria spread from the breeding environment onto the meat through the
food production chain. We thus analyzed the occurrence and abundance of ARGs, as well as comparing both ARG and bacterial
community compositions in farm soil, pig feces and pork samples from a large-scale pig farm located in Xiamen, People’s Republic of
China. Among the 26 target ARGs, genes conferring resistance to sulfonamide, trimethoprim, aminoglycoside, chloramphenicol,
macrolide, florfenicol, and tetracycline were observed at high frequency in both the pig breeding environment and pork. The
prevalence of ARGs in pork was surprisingly consistent with breeding environments, especially between the pork and feces. The
relative abundance of 10 representative ARGs conferring resistance to six classes of antibiotics ranged from 3.01 × 10−1 to 1.55 ×
10−6 copies/16S rRNA copies. The ARGs conferring resistance to sulfanilamide (sulI and sulII), aminoglycoside (aadA), and tetracycline
[tet(A) and tet(M)] were most highly abundant across most samples. Samples from feces and meat possessed a higher similarity in
ARG compositions than samples from the farms soil. Enterobacteriaceae found on the meat samples were further identical with
previously isolated multidrug-resistant bacteria from the same pig farm. Our results strongly indicate that ARGs can be potentially
spreading from pig breeding environment to meat via the pork industry chain, such as feed supply, pig feeding and pork
production.Medical Research Council (MRC)European Commissio
