ANTIMICROBIAL SUSCEPTIBILITY PATTERN AND MAR INDEX OF Staphylococcus aureus ISOLATED FROM HEALTHCARE WORKERS IN A GENERAL HOSPITAL IN LAGOS STATE, NIGERIA.

Abstract

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) is increasing in hospital settings and is a marker for multiple drug resistance to commonly prescribed antibiotics. Forty (40) MRSA and fteen (15) methicillin-sensitive Staphylococcus aureus (MSSA) isolated from healthcare workers (HCWs) at Isolo General Hospital, Lagos State were subjected to antimicrobial susceptibility testing with selected antibiotics and their multiple antibiotic resistance (MAR) index values were calculated. MRSA isolates showed the highest resistance to Ciprooxacin (70.0%) and Erythromycin (67.5%) and lowest resistance to Mupirocin and Linezolid (17.5%). The MSSA isolates showed high levels of susceptibilities to Linezolid (100%), Gentamicin (93.3%) and Mupirocin (86.7%). Resistances of MSSA ranged from 0.00% (linezolid) to 40.0% (Erythromycin), with other antibiotics having intermediate values. Erythromycin resistance of MSSA (40.0%) is an emerging problem for an antibiotic which currently serves as alternative in penicillin-allergic patients. The MAR index values of MRSA and MSSA isolates ranged from 0 to 1.0 and 0 to 0.5 respectively, an indication that majority of the MRSA isolates and a few of MSSA were hospital acquired. These data show that antimicrobial resistance is increasing among Staphylococcus aureus strains in the study area. This calls for implementation of infection control measures including routine MRSA screening of HCWs, MRSA screening for all patients admitted to the hospital, urgent reporting of MRSA laboratory results, improved hygiene, and adoption of antimicrobial policy that minimizes in appropriate or excessive antibiotic therapy and prophylaxisin our hospitals to prevent the spread of MRSA and other resistant microorganisms.