Abstract

The aim of this study was to investigate the inducible clindamycin resistance in 306 strains of staphylococci, isolated from various clinical samples over a period of two years. Inducible clindamycin resistance was investigated by D-test using clindamycin and erythromycin discs as per the CLSI guidelines. Out of 177 Staphylococcus aureus strains 53 (17.3%) were methicilline resistant S. aureus (MRSA) and 124 (40.5 %) were methicillin sensitive S. aureus (MSSA). Among the coagulase negative staphylococci, 121 (39.6%) were methicillin sensitive and 8 (2.6%) were methicillin resistant. Out of 306 clinical isolates 99 (36.4%) showed erythromycin resistance. Among the erythromycin resistant isolates 46 (46.5%) were CoNS of which 8 (15.1%) were MRCoNS and 38 (31.4%) MSCoNS. Out of thirty-one erythromycin resistant isolates 20 (6.5% of the total isolates) belonged to MLSBi phenotype, eleven isolates belonged to MLSBc phenotype. We conclude that it is necessary to perform D-test for detection of inducible clindamycin in staphylococci in routine antibiotic susceptibility testing.

Key words: Staphylococci, D test, inducible clindamycin resistance.

Abbreviation

MRSA, methicilline resistant S. aureus; MSSA, methicillin sensitive S. aureus; MSCONS, methicillin sensitive coagulase-negative staphylococci; MRCoNS,methicillin resistant coagulase-negative staphylococci.