Relationship between phenotypic and genotypic florfenicol resistance in Escherichia coli

Singer RS, Patterson SK, Meier AE, Gibson JK, Lee HL, Maddox CW
Antimicrobial Agents and Chemotherapy 48:4047-4049

This study evaluated the relationship between florfenicol resistance and flo genotypes in 1,987 Escherichia coli isolates from cattle. The flo gene was detected in 164 isolates, all of which expressed resistance to florfenicol at MICs of >/=256 microg/ml. The florfenicol MICs for all isolates that lacked flo were