Determine Constitutive and Inducible Clindamycin Resistance among Clinical Isolates of Staphylococcus Aureus Isolates from Tertiary Care Hospital, Bettiah, India

Introduction: Clindamycin has been used to treat pneumonia and soft tissue and musculoskeletal infections due to MRSA. One important problem in Clindamycin treatment is the risk of clinical failure during therapy caused by MLSB inducible resistance. The Clinical and Laboratory Standards Institute (CLSI) suggest D-test, which is a phenotypic showing technique for inducible Clindamycin resistance. Material and Methods: We analyzed antimicrobial susceptibility testing by Kirby Bauer disk diffusion method. Methicillin resistance was detected with cefoxitin (30 μg) disk and inducible clindamycin resistance was unwavering in all erythromycin resistant isolate by using D-zone test. Results: 100 S. aureus isolate 37 (36.6%) were methicillin resistant (MRSA) and 63 (63.4%) were methicillin-sensitive S. aureus (MSSA). Although, mainstream of the MRSA isolates were imitative from pus samples 15, however, the S. aureus isolates imitative from post-operative wound infection were mainly MRSA 7. A total of 21 S. aureus isolates with iMLSB phenotype shown that they were 100% susceptible to vancomycin and linezolid, with modest sensitivity (71.14%) to gentamicin, cefuroxime and slightest sensitivity to (23.81%) doxycycline, (20.95%) ciprofloxacin. Conclusion: Outstanding to high happening of erythromycin resistance amongst S. aureus isolates, we recommend that D-zone test have to be regularly done in all laboratories for suitable recommendation of clindamycin and thus preventing appearance of inducible resistant strains and management failure.