Prevalence of Inducible Clindamycin Resistance of Staphylococcus aureus in Hospitalized Patients in Tertiary Care Hospital

Background: Methicillin resistant Staphylococcus aureus (MRSA) has emerged as one of the most common pathogen isolated from patients with very few drugs available for their treatment.Clindamycin is a good alternative optional drug for the treatment of these infections.In vitro routine testing may fail to detect such resistance.Thus it is important to detect such resistance by simple D test. Material and Methods:300 staphylococcal isolates where isolated from clinical samples by conventional microbiological methods.Of these 208(69.33%)were identified as Staphylococcus aureus.Methicillin resistance and inducible clindamycin resistance was detected by cefoxitin disk diffusion method and D test as per CLSI guidelines respectively.Results: 135 (64.9%) were MRSA and 73 (35.09%) were Methicillin sensitive Staphylococcus aureus (MSSA), 45(21.63%)isolates showed inducible clindamycin resistance, 19(9.1%)showed constitutive clindamycin resistance, 112(53.84%)showed MS phenotype whereas 32(15.38%)were erythromycin sensitive.Inducible clindamycin resistance and constitutive clindamycin resistance was higher in MRSA than in MSSA (25.92%, 11.11% and 13.69%, 5.47% respectively).Conclusion: D test should be done as routine test in all Microbiology laboratory for detection of true resistance of clindamycin among staphylococcal isolates.