Distribution and Transfer of Plasmid Replicon Families among Multidrug-Resistant and from Poultry.

The presence and transfer of plasmids from commensal bacteria to more pathogenic bacteria may contribute to the dissemination of antimicrobial resistance. However, the prevalence of plasmids from commensal bacteria, such as the enterococci, in food animals remains largely unknown. In this study, the diversity and prevalence of plasmid families from multidrug-resistant (MDR; resistance to three or more antimicrobials) enterococci from poultry carcasses were determined. Plasmid-positive MDR enterococci were also tested for the ability to transfer plasmids to other enterococci using conjugation. MDR ( = 98) and ( = 696) that were isolated from poultry carcass rinsates between 2004 and 2011 were tested for the presence of 21 plasmid replicon () families using multiplex PCR. Approximately 48% of (47/98) and 16% of (110/696) were positive for at least one -family. Fourteen -families were detected overall, and ten -families were shared between and . The and families were unique to , while the and families were unique to . The family was predominant in both and for all the years tested. The greatest number of -families detected was in 2005 ( = 10), and the least was in 2009 ( = 1). Eight -families were transferred from donors to the JH2-2 recipient using conjugation. Results from this study showed that and from poultry carcasses contain numerous and diverse -families that are capable of conjugal transfer.