Introduction: Staphylococcus aureus is increasingly recognized as a cause of hospital associated (HA) and community associated (CA) infections. The Macrolide-lincosamide-StreptograminB (MLSB), family of antibiotics serves as one such alternative, clindamycin being the preferred agent due to its excellent pharmacokinetic properties. However widespread use of clindamycin led to increase in resistance due to target site modification mediated by erm genes which can be expressed either constitutively or inducibely so use of D-test in a routine laboratory enables us to guide clinicians in judicious use of clindamycin. Aims and Objective: To study prevalence of inducible and constitutive clindamycin resistance among Staphylococcus aureus and to compare in between MRSA and MSSA isolates. Material and Methods: A total of 107 Staphylococcus aureus isolates were subjected to routine antibiotic susceptibility testing including cefoxitin (30mcg) by Kirby Bauer disc diffusion method. Inducible clindamycin resistance was detected by using D test, as per CLSI guidelines on erythromycin resistant isolates. Results: A total of 67 isolates were resistant to erythromycin. Among 67 isolates, 17(25.37%) showed inducible Clindamycin resistance, 27(40.2%) showed MS phenotype and Constitutive resistance was seen in 23(34.3%) isolates. Constitutive and inducible clindamycin resistance was found to be higher in MRSA as compared to MSSA. Conclusion: For efficient use of clindamycin, D-test should be used as a mandatory method in routine disc diffusion testing to detect Inducible clindamycin resistance. 

Keywords: Constitutive; Inducible Clindamycin Resistance; MRSA; MSSA.