Inducible and constitutive clindamycin resistance in Staphylococcus aureus: an experience from Western Nepal

Abstract Objective: This study aimed to determine prevalence of inducible and constitutive clindamycin resistance among clinical S. aureus isolates and also study their association with methicillin resistance. Methods: A cross-sectional study including 140 non-duplicate isolates of S. aureus was done. Isolates were identified by standard microbiological methods and methicillin resistance was detected by cefoxitin disc diffusion method. Inducible clindamycin resistance was detected by D-test. Results: Prevalence of inducible and constitutive clindamycin resistance was 12.10% and 7.90% respectively. Constitutive and inducible resistance was associated with MRSA. An unusual phenotype, erythromycin sensitive and clindamycin resistance, was detected in 2 MRSA isolates. Conclusions: Inducible and constitutive clindamycin resistance is low in our setting. Constitutive and inducible resistance was associated with MRSA. However the trends in resistance vary in different places. D-test reporting should be done routinely which will allow clinicians to opt for clindamycin judiciously and avoid potential treatment failure. Keywords: Clindamycin resistance, MLSBi, D-test, MRSA, Nepal