In VitroAntibiotic Susceptibilities of Yersinia pestis Determined by Broth Microdilution following CLSI Methods

Abstract

ABSTRACTIn vitrosusceptibilities to 45 antibiotics were determined for 30 genetically and geographically diverse strains ofYersinia pestisby the broth microdilution method at two temperatures, 28°C and 35°C, following Clinical and Laboratory Standards Institute (CLSI) methods. TheY. pestisstrains demonstrated susceptibility to aminoglycosides, quinolones, tetracyclines, β-lactams, cephalosporins, and carbapenems. Only a 1-well shift was observed for the majority of antibiotics between the two temperatures. Establishing and comparing antibiotic susceptibilities of a diverse but specific set ofY. pestisstrains by standardized methods and establishing population ranges and MIC50and MIC90values provide reference information for assessing new antibiotic agents and also provide a baseline for use in monitoring any future emergence of resistance.