An Integrated Surveillance for Antimicrobial-Resistance in Salmonella from Clinical and Retail Meat Sources — Pennsylvania, 2009-2013
Methods: During August 2009 through June 2013, Salmonellaisolates from meat (chicken breasts, ground turkey, ground beef, and pork chops, 470 of each) purchased from randomly selected retail outlets in southeastern Pennsylvania were analyzed by pulsed-field gel electrophoresis (PFGE). We compared the PFGE patterns with those of clinical isolates in the Pennsylvania surveillance database. All meat isolates and a subset of matched clinical isolates were tested for susceptibility to antimicrobial agents.
Results: A total of 148 Salmonellaisolates were recovered from 1880 meat samples: 20% of chicken samples, 9.6% of turkey, 0.64% of beef, and 1.3% of pork were culture-positive. PFGE patterns of 66 (44.6%) retail meat isolates had PFGE matches among 1304 clinical isolates; 28 distinct PFGE patterns were represented. Sixteen (57.1%) of these patterns were associated with multi-drug resistance (resistance to ≥3 antimicrobial agents), and 11 (39.3%) were associated with drug-resistance profiles that were identical to profiles of PFGE-matched retail meat isolates. One Dublin PFGE pattern found in 10 clinical isolates and one beef isolate was associated with resistance to ≥6 antimicrobial agents. All eleven isolates demonstrated resistance to ampicillin and ceftriaxone. Six distinct patterns of clinical Typhimurium isolates shared resistance profiles that were identical to matched retail meat isolates. One isolate from pork was resistant to the same five antimicrobial agents (ACSSuT phenotype) as were 22 clinical Typhimurium isolates.
Conclusion: In this comparison, Salmonella isolates known to have caused human illness had PFGE patterns indistinguishable from those found in retail meats. Of these, more than half were multidrug resistant. These data suggest that some antimicrobial resistant Salmonella infections in humans originate from contaminated retail meat.
B. Perry, None
L. Dettinger, None
D. Tewari, None
Y. L. Li, None
H. Tate, None