Analysis of the inducible clindamycin resistance in 71 staphylococcal strains

ObjectiveTo investigate the prevalence of inducible clindamycin resistance in Staphylococcus isolated from the Shanghai Sixth People's Hospital in 2004 and the effect of disk distance on test results.MethodsA total of 71 strains of Staphylococcus resistant to erythromycin and intermediate or susceptible to clindamycin were collected in 2004,including 16 strains of Staphylococcus aureus and 55 strains of coagulase-negative Staphylococcus.The inducible clindamycin resistance(D Test) was tested by double disk diffusion method.The strains with positive result should be done in 4 groups of disk distance 10-15 mm,16-20 mm,21-25 mm and 26-28 mm again to examine the effect of disk distance on the results of D Test.ResultsThe prevalence of inducible clindamycin resistance was 45.1% in Staphylococcus spp.,68.8% in S.aureus and 38.2% in coagulase-negative Staphylococcus(P0.05).The disk distance beyond 26 mm would affect the result of D Test.ConclusionsThe detection of inducible clindamycin resistance in staphylococcal isolates should be stressed in microbiology laboratory.