Detection of Virulence Plasmid-Encoded Genes in Typhimurium and Kentucky Isolates Recovered from Commercially Processed Chicken Carcasses.

serovar Typhimurium is one of the leading causes of nontyphoidal gastroenteritis of humans in the United States. Commercially processed poultry carcasses are frequently contaminated with serovar Kentucky in the United States. The aim of the study was to detect the virulence plasmid containing the genes from isolates recovered from commercially processed chicken carcasses. A total of 144 isolates ( Typhimurium, = 72 and Kentucky, = 72) were used for isolation of plasmids and detection of corresponding virulence genes ( and ). Only four (5.5%) Typhimurium isolates tested positive for all three virulence genes and hence were classified as possessing the virulence plasmid. All isolates of Kentucky were negative for the virulence plasmid and genes. These results indicate that the virulence plasmid, which is very common among clinical isolates of Typhimurium and other serovars (e.g., Enteritidis, Dublin, Choleraesuis, Gallinarum, Pullorum, and Abortusovis), may not be present in a significant portion of commercially processed chicken carcass isolates.