Clindamycin has been an alternative to methicillin as a result of incrase the prevelance of methicillin resistant staphylococci strains. However, inducible Macrolide-Lincosamide-Streptogramin B (iMLSB) resistance to clindamycin could limit the use of this drug. The aim of this study was to determine the prevalance of iMLSB resistance in staphylococci strains, isolated from various clinical samples. 79 (21%) methicillin resistant Staphylococcus aureus (MRSA) and 60 (16%) methicillin sensitive S. aureus (MSSA), 154 (41.1%) methicillin resistant and 82 (21.9%) methicillin sensitive coagulase negative stapylococci for a total of 375 isolates were included in this study. iMLSB resistance was investigated by D-test using clindamycin and erytromycin disk on the basis of guidelines by the Clinical and Laboratory Standards Institute. 223 of total 375 staphylococci isolates were found to be resistant to erythromycin (ER-R). 55 (24.6%) of total 223 (59.5%) ER-R isolates showed iMLSB phenotype. 40 of 55 iMLSB resistant isolates were also methicillin resistant. Since iMLSB resistance is not detected by classical susceptibility tests, using of D-test on a routine laboratory application will help safety usage of clindamycin in treatment of especially methicillin resistant staphylococci infections.

Keywords: Coagulase negative staphylococci, D-test, Inducible clindamycin resistance, Staphylococcus aureus.