Submitted to: American Society for Microbiology Annual Meeting
Publication Type: Abstract only
Publication Acceptance Date: 5/2/2008
Publication Date: 6/1/2008
Citation: McDermott, P., Anandaraman, N., Haro, J.H., Ball, T.A., Hall-Robinson, E., Blickenstaff, K., Carter, P., Cray, P.J. 2008. Antimicrobial Resistant E. coli from Retail Chicken Breast and Slaughter Rinsates: NARMS 2002-2005 [abstract]. American Society for Microbiology Annual Meeting. CD-ROM. P-069. Interpretive Summary:
Technical Abstract: Background: The National Antimicrobial Resistance Monitoring System tracks resistance trends among non-type-specific E. coli from chicken carcasses at slaughter and chicken breast meat at retail. Methods: From 2002-2005, a monthly sampling of chicken breasts from stores in GA, MD, OR and TN yielded 7218 meats samples. During this same time, 12,470 chicken carcasses rinsates were obtained from federally inspected slaughter and processing plants. Meats and rinsates were cultured for E. coli using standard methods and tested for antimicrobial susceptibility following the CLSI. Results: E. coli were detected in 69% of retail meats and 59% of rinsates. Multidrug resistance (resistance to > 3 agents) was present in 38% of meat isolates and 43% of the carcass isolates. Resistance rates for retail and rinsate isolates, respectively, were: tetracycline (50%, 53%), streptomycin (36%, 63%), sulfonamides (33%, 49%), ampicillin (20%, 20%), and gentamicin (17%, 38%). In meat isolates from 2002-2005, increasing resistance was seen for gentamicin (23%-38%), ampicillin (22-25%), ceftiofur (7-9%), trimethoprim/sulfamethoxazole (4-7%), chloramphenicol 0.8%-2.3%) and nalidixic acid (3-6%). Resistance decreased for streptomycin (36%-32%) and tetracycline (52%-49%). Ceftriaxone resistance was limited to 3 isolates in 2005 (0.2%). Resistance in carcass isolates decreased or was stable for streptomycin (65%-58%), gentamicin (38%-37%), trimethoprim/sulfamethoxazole (10%-10%), chloramphenicol (2%-1%), ceftriaxone (0%-0%) and tetracycline (59%-49%). Slight increases in resistance were seen for ampicillin (19%-22%), nalidixic acid (7%-8%) and ceftiofur (6%-7%). Ciprofloxacin resistance was rare in isolates from meat (<0.5%) and rinsates (0.2%). Ceftiofur resistant retail isolates were tested for 5 relevant beta-lactamase genes, cmy, ctx-m, oxa, shv, and tem. All were positive for cmy and 16% were tem positive. Summary: This study showed that antimicrobial-resistant E. coli are present in chicken carcasses at slaughter and in retail chicken breast meat. The four years of NARMS data presented here indicate that resistance was generally more frequent in isolates from carcass rinsates.