Submitted to: International Journal of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/3/2006
Publication Date: 7/20/2006
Citation: Berrang, M.E., Ladely, S.R., Cray, P.J., Simmons, M., Fletcher, D.L. 2006. Antimicrobial resistance patterns of salmonella from retail chicken. International Journal of Poultry Science. 5(4):351-354.
Interpretive Summary: Antimicrobial resistant Salmonella can cause foodborne disease that is difficult to treat with antibiotic therapy. Salmonella can be recovered from poultry and poultry products; however, there is limited published data relative to the prevalence of antimicrobial resistant Salmonella on chicken products purchased at retail outlets in the US. Eighty isolates of Salmonella were recovered from fresh whole chicken carcasses purchased at retail grocery stores in Northeast Georgia. All isolates were sero-grouped using serogroup specific antisera and tested to determine their susceptibility to 18 antimicrobial drugs. Fifteen different serotypes were detected with the most prominent identified as S. Heidelberg, S. Typhimurium 5- (formerly var. copenhagen) and S. Kentucky. Approximately 44 % of the isolates were resistant to one or more antimicrobial drugs. The most common drugs to which bacteria were resistant were tetracycline and ampicillin both of which are members of drug classes which have been used in chicken feed to enhance feed efficiency and growth. Another common resistance was to the drug streptomycin. Some isolates were resistant to more than one drug. Thirteen isolates (16%) were resistant to 5 or more drugs. No resistance was noted to ciprofloxacin a drug which may be used to treat human salmonellosis. Nevertheless, these data indicate that antimicrobial resistant salmonellae can be recovered from chicken meat purchased at retail outlets in the US. Therefore, consumers should apply proper food handling procedures when preparing chicken.
Technical Abstract: Salmonella is frequently reported as a cause of food-borne illness. The emergence of antimicrobial resistant Salmonella associated with meat products has heightened concerns regarding antimicrobial use in food animal production. Eighty Salmonella isolates recovered from fresh whole chicken carcasses purchased at retail outlets were examined for susceptibility to 18 antimicrobials. Fifteen serotypes were identified; the top five included; S. Heidelberg (25%), S. Typhimurium 5- (formerly var. copenhagen) (18.75%), S. Kentucky (17.5%), S. Berta (11.25%), and S. Hadar (8.75%). Overall, resistance was most commonly observed to tetracycline (25%), ampicillin (22.5%), streptomycin (21.25%) and cephalosporin derivatives (cephalothin 18.75%, ceftiofur 16.25%, and cefoxitin 15%). Of all isolates, 43.75% were resistant to one or more antimicrobial and 36 % were identified as multi-drug resistant (MDR, resistant to 2 or more antimicrobials). Fourteen resistance patterns were observed and among isolates showing resistance, 22.5% were resistant to 1-3 antimicrobials, 16.25% were resistant to 4-6 antimicrobials, and 5.0% were resistant to ' 7 antimicrobials. The prevalence of antimicrobial resistance varied by serotype. All 7 S. Hadar isolates were resistant to 1-2 antimicrobials, 4 of 20 S. Heidelberg isolates were resistant to 1-3 antimicrobials, 10 of 15 S. Typhimurium 5- isolates were resistant to 4-5 antimicrobials, 7 of 14 S. Kentucky isolates were resistant to 1-7 antimicrobials, and 3 of 9 S. Berta isolates expressed resistance to 9-11 antimicrobials. These data indicate that Salmonella recovered from retail poultry carcasses may be resistant to multiple antimicrobials, and that resistance among these isolates varies by serotype.