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.
MRSA;Inducible clindamycin resistance;D test