Detection and analysis for induction of clindamycin resistance in coagulase-negative Staphylococcus

Objective To investigate the resistance of coagulase-negative Staphylococcus(CNS) to erythromycin and clindamycin and the percentage for inducible resistance in order to analyse CNS resistance mechanism to macrolides antibotics in our region.Methods The susceptibilities of erythromycin and clindamycin for 280 CNS strains were determined by double disk diffusion test and the inducible resistance of erythromycin to clindamycin was detected by D test.Results The rates of co-resistance and co-sensitivity to erythromycin and clindamycin accounted for 15.7% and 37.5% in CNS isolated from our hospital,respectively.And other isolates of CNS resistant to erythromycin but susceptible to clindamycin accounted for 46.8%.In addition,the rates of inducible resistance to clindamycin were 57.3%,56.8% and 66.7% in total CNS,methicillin-resistant CNS(MRCNS) and methicillin-susceptible CNS(MSCNS) which possessed erythromycin-resistant and clindamycin-susceptible by individual disk diffusion test,respectively.Conclusions The detection of inducible clindamycin resistance must be stressed in clinical microbiology laboratory in order to guide physicians to select reasonable antibiotics for CNS infection.