prevalence of clindamycin inducible resistance in staphylococcus aureus and coagulase-negative staphylococci using d-test: a short report

background and objective: the d-test is performed by placing clindamycin and erythromycin impregnated disks at a standard distance on the agar plate then looking for the flattening of inhibition zone around the clindamycin disk. a positive d-test indicates clindamycin inducible resistance and also predicts treatment failure possibility of this antibiotic in clinic. prevalence of staphylococcal inducible resistance to clindamycin through the d-test was the aim of this study. materials and methods: in this descriptive-cross-sectional study, inducible resistance to clindamycin was examined on the 150 isolated staphylococcus aureus (n=103) and coagulase-negative staphylococci (n=47) collected from nasal employees and clinical samples by using d-test. the statistical analysis was performed using chi-square test. results: out of 103 isolated s. aureus, 22 (21.4%) were methicillin-resistant (mrsa). among the tested samples, 3(2%), 1(0.6%) and 2(1.3%) had d, d+ and hd phenotypes, respectively. fifty-four (36%) of isolations exhibited resistance to both clindamycin and erythromycin. prevalence of resistance to clindamycin and erythromycin between isolated mrsa and methicillin-susceptible s. aureus (mssa) was statistically significant (p< 0.05). conclusion: phenotypical resistance to erythromycin is not always attributable to clindamycin resistance. therefore, staphylococcus strains resistant to erythromycin and susceptible to clindamycin should be subjected to d-test assay. key words: inducible resistance, clindamycin, staphylococcus aureus, d-test   funding: this research was funded by lorestan university of medical sciences. conflict of interest: none declared. ethical approval: the ethics committee of lorestan university of medical sciences approved the study.   how to cite this article: goudarzi gh.r, azadpour m. prevalence of clindamycin inducible resistance in staphylococcus aureus and coagulase-negative staphylococci using d-test: a short report. j rafsanjanuniv med sci 2015 14(1): 77-82. [farsi]