Molecular Characterization of Plasmids Associated With Strains Isolated From Various Retail Meats.

is considered one of the most important foodborne bacterial pathogens causing food poisoning and related illnesses. strains harbor plasmids encoding genes for virulence and antimicrobial resistance, but few studies have investigated plasmids, especially megaplasmids, in isolates from retail meats. Furthermore, knowledge about the distribution of genes encoding replication () initiation proteins in food isolates is lacking. In this study, the prevalence of plasmids in strains isolated from retail meats purchased in Oklahoma was investigated; furthermore, we evaluated associations between families, selected virulence and antimicrobial resistance genes, and food source origin. Two hundred and twenty-two isolates from chicken ( = 55), beef liver ( = 43), pork ( = 42), chicken liver ( = 29), beef ( = 24), turkey ( = 22), and chicken gizzards ( = 7) were subjected to plasmid screening with alkaline lysis and PFGE to detect small-to-medium sized and large plasmids, respectively. The isolates contained variable sizes of plasmids, and PFGE was superior to alkaline lysis in detecting large megaplasmids. A total of 26 families were identified by PCR, and the most dominant families were and in 164 isolates (89%), in 124 isolates (56%), and in 99 isolates (45%). Relationships between selected genes, antimicrobial resistance and virulence genes, and meat sources were detected. In conclusion, strains isolated from retail meats harbor plasmids with various sizes and there is an association between genes on these plasmids and the meat source or the antimicrobial resistance of the strains harboring them.