Variations of 23S rRNA V region gene of two linezolidintermediate Enterococcus faecalis strains

Abstract:

ObjectiveTo evaluate antimicrobial resistance and antimicrobial resistance mechanisms of Enterococcus faecalis (E. faecalis)  to linezolid(LNZ)，and provide basis for clinical rational drug use.  MethodsTwelve E. faecalis strains isolated from sputum of patients who received LNZ therapy in a hospital between January  2012 and January  2013 were collected. The minimum inhibitory concentrations (MICs) of antimicrobial agents were determined by agar dilution method， 23S rRNA V region gene of E.faecalis was amplified by polymerase chain reaction, the amplified products were sequenced. ResultsOf 12 isolates, 2 were intermediate strains and 10 sensitive strains. The G2576U mutation was detected in 2 intermediate strains， 1 of which was also detected  G2424U mutation; the variations were not detected in 10 sensitive strains. C2424U and G2576U mutation existed in R1 and R4 region respectively. Conclusion23S rRNA V region gene mutations are found in the intermediate strains of E. faecalis. Change in MIC values of linezolid should be paid close attention in clinical use.