A STUDY ON INDUCIBLE CLINDAMYCIN RESISTANCE AMONG STAPHYLOCOCCUS AUREUS IN A TERTIARY CARE HOSPITAL

Clindamycin resistance has been reported due to constitutive or by the presence of low level inducers due to erm genes. The routine antimicrobial susceptibility testing for clindamycin may fail to detect inducible clindamycin resistance resulting in treatment failure. These strains can be detected by simple routine D-test (disc diffusion test) as per the CLSI guidelines. This present study was aimed to detect percentage of inducible Clindamycin resistance among the MRSA and MSSA Staphylococcus aureus isolates from various clinical samples. A total of 524 Staphylococcus aureus isolates were obtained among which 219 (41.79%) were MRSA and 305 (58.21%) were MSSA. Highest isolation of S.aureus 463 (88.36%) were found in pus samples. Among the 524 S.aureus isolates, 93(17.75%) were inducible phenotype (i MLSB), 71 (13.55%) were constitutive phenotype (c MLSB), and 78(14.88%) were MS phenotype (MSB). The inducible, constitutive and MS phenotypes were 47 (21.46%), 38 (17.35%) and 26 (11.87%) among 219 MRSA isolates, and 46 (15.08%), 33 (10.82%) and 52 (17.05%) among 305 MSSA isolates respectively. The percentages of inducible and constitutive resistance were found to be higher amongst MRSA isolates than MSSA isolates and routine ‘D’ test can be used to detect the inducible clindamycin resistance for all erythromycin resistant isolates. In order to guide the clinicians regarding judicious use of clindamycin in skin and soft tissue infections as well as to prevent therapeutic failure.