Identification and Antimicrobial Resistance of Extraintestinal Pathogenic Escherichia coli from Retail Meats

Extraintestinal pathogenic Escherichia coli (ExPEC) causes a variety of infections outside the gastrointestinal tract. Retail meats are frequently contaminated with E. coli strains, and they might serve as a vehicle for transmitting ExPEC. A total of 1,275 E. coli isolates recovered from ground beef, ground turkey, chicken breasts, and pork chops obtained in Georgia, Maryland, Oregon, and Tennessee in 2006 were investigated for the presence of ExPEC by using multiplex PCR. Identified ExPEC isolates were assigned to serogroups and phylogenetic groups and then analyzed for antimicrobial susceptibility. Approximately 16% (200 of 1,275) of the E. coli isolates were identified as ExPEC, based on defined genetic criteria. The occurrence of ExPEC was highest in E. coli isolated from ground turkey (23.5%) and chicken breasts (20.2%), and less frequent in isolates from pork chops (8.3%) and ground beef (3.4%). Phylogenetic grouping revealed that most (66.5%) ExPEC isolates fell into the same phylogenetic groups (B...