PATTERNS OF PHENOTYPIC RESISTANCE TO THE MACROLIDE LINCOSAMIDE STREPTOGRAMIN-B GROUP OF ANTIBIOTICS IN PVL POSITIVE Staphylococcus aureus IN TERTIARY CARE HOSPITAL

Background and Objectives: Methicillin resistant Staphylococcus aureus (MRSA) infections are increased recently. Most of the MRSA harbor by panton valentine leukocidin (PVL) gene which is responsible for virulence. Although changing patterns in antimicrobial resistance, increases the interest in the use of macrolide lincosamides streptogramin B (MLSB) antibiotics to treat staphylococcal infection. In the present study, we aimed to find out prevalence of inducible resistance (iMLSB) and constitutive resistance (cMLSB) to clindamycin in MRSA isolates which has PVL gene.

Materials and Methods: We included all 100 MRSA isolates confirmed by PCR method for mecA gene from various clinical specimens which were isolated from different departments of our institute.

Results: Among these 100 MRSA isolates, 62% were PVL positive and 38% were PVL gene negative. Out of these 62 strains, 28 (45.16%) were erythromycin resistant. We found 6 (21.42%) isolates showed iMLSB phenotype (D-test positive), no one strain showed cMLSB phenotype that is 0% cMLSB and 22 (78.57%) showed D- test negative suggesting MS phenotype.

Conclusion: The incidence of MLSB phenotypes and genotypes varies according to country, patterns of infections and use of drug. It is suggested that MLSB resistance in MRSA should be under constant surveillance in every country, state as well as in region.