Plasmid profile of Enterococcus faecium and Enterococcus faecalis isolated from pigs, pork and humans in Thai-Laos border provinces

This study aimed to determine plasmid profile of E. faecium and E. faecalis isolated from pigs, pig products and humans in Thailand-Laos border provinces. A total of 96 Enterococcus spp. including E. faecium (n=59) and E. faecalis (n=37) from pigs, pork and humans were included. All were determined for their antimicrobial susceptibilities and plasmid profile. Most isolates (96.9%) carried one to four plasmids with a molecular weight of 0.03-35 kb in E. faecium and 19-40 kb in E. faecalis. The 26 kb plasmid was most commonly detected. Variable plasmid profiles were defined, of which the most common pattern was, 23 kb in E. faecalis and, 35 kb in E. faecium. In conclusion, the results indicate a wide distribution of plasmids among the Enterococcus isolates originating from pig, pork and humans in this strain collection and confirm the important role of commensal E. faecium and E. faecalis as a reservoir for the emergence and spread of AMR among food animals and humans.