Prevalence and Clinical Significance of Inducible Clindamycin Resistance in Staphylococcal Strains

OBJECTIVE To investigate the resistance of the isolated staphylococci to erythromycin and clindamycin and the frequency of inducible clindamycin-resistance of the isolates. METHODS The susceptibilities of erythromycin and clindamycin of the isolates were examined by Kirby-Bauer disc agar diffusion test and the inducible clindamycin-resistance was detected by D-zone test.Cefoxitin disk diffusion test was used for detection of meticillin-resistant staphylococci. RESULTS Among the total of 219 staphylococcus strains,119(54.34%) were resistant to both erythromycin and clindamycin(cMLS) and 45(20.55%) were resistant to erythromycin but susceptible to clindamycin and showed positive D-test results(iMLS).In the phenotype of resistant to erythromycin but susceptible to clindamycin the rates of inducible clindamycin-resistance of MRSA,MSSA,MRCNS and MSCNS were 64.71%,54.55%,70.37% and 60.00%,respectively. CONCLUSIONS.D-test should be performed to find erythromycin-resistant and clindamycin-susceptible isolates of staphylococci.