H-11
Identification of Significant Co-resistance among Quinupristin-Dalfopristin-Resistant Enterococcus faecium Isolated from Retail Meats
J. R. Hayes1, D. D. Wagner1, L. L. English1, P. J. Carter1, T. Proescholdt2, K. Y. Lee2, D. G. White1, 1OR, CVM, FDA, Laurel, MD, 2OSC, CVM, FDA, Rockville, MD
The long-term use of the streptogramin analogue, virginiamycin, in food animal production has led to a reservoir of Q-D-resistant E. faecium (QDREF) isolates from animal products. This study was undertaken to determine the magnitude of association between resistance to Q-D and other antimicrobial agents among isolates of E. faecium from retail foods of animal origin.
From a collection of E. faecium isolated from retail meats from Iowa, Q-D susceptible (587) and resistant populations (238) were statistically compared to determine the degree of association between Q-D resistance and other tested antimicrobials, measured by the prevalence of resistance and described by the odds ratio (OR).
Among the QDREF isolated from the four meat sources, significant co-resistance phenotypes were observed with tetracycline (57-93%, OR 2.3-18) and lincomycin (88-98%, OR 4.7-39) among isolates from poultry and ground beef. Q-D resistance was associated with resistance to erythromycin among ground turkey (60%, OR 1.8) and chicken (35%, OR 3.0) isolates whereas co-resistance to tylosin was significant among isolates from chicken (32%, OR 3.9) and ground beef (46%, OR 12). Co-resistance was observed with high-level streptomycin resistance among chicken isolates (53%, OR 7.6) and to nitrofurantoin (67%, OR 2.3) and high-level kanamycin resistance (74%, OR 72) among isolates from ground beef.
The finding of significant co-resistance phenotypes among QDREF recovered from different retail meats suggests that there are differences in the antimicrobial selection pressures exerted among the tested food animal production environments and that other antimicrobial agents may co-select for QDREF within these environments.
2004 FDA Science Forum | FDA Chapter, Sigma Xi | CFSAN | FDA
Last updated on 2004-APR-02 by frf