PREVALENCE AND SUSCEPTIBILITY OF MRSA IN NASAL AND HAND CARRIAGE AMONG THE ICU PATIENTS AND HEALTH CARE WORKERS AT TERTIARY CARE HOSPITAL, CHENNAI: ASSESSMENT OF MUPIROCIN AND BACTERIOCIN EFFICACY

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a prominent nosocomial pathogen, often residing as commensals in skin and mucosa, posing a risk for severe infections. Healthcare workers (HCWs) colonized with MRSA significantly contribute to hospital-acquired infections (HAI) and transmission within healthcare settings. While mupirocin has been a primary decolonizing agent for MRSA carriers, increasing resistance has necessitated exploration of alternative treatments like bacteriocins, bactericidal peptides synthesized by bacteria effective against various pathogens, including MRSA. Method: We conducted a six-month cross-sectional study involving 118 participants (90 HCWs and 28 ICU patients), collecting nasal and hand swabs processed per CLSI guidelines. MRSA was detected using the cefoxitin disc diffusion method, and mupirocin resistance was assessed using a 200 μg mupirocin disc. Bacteriocin was extracted from Pseudomonas aeruginosa, and its antibacterial activity against MRSA isolates was evaluated through agar-well diffusion. Results: Among 236 swabs, 8.9% were positive for S. aureus, with MRSA identified in 42.8% of these cases. The overall MRSA carriage rate was 5.9% (7/118), with 29% showing MRSA in both nasal and hand swabs. Hand carriage (5%) was more prevalent than nasal carriage (2.5%), particularly among technicians (20%). Mupirocin resistance was observed in 22% (MuH) and 78% (MuL) of MRSA isolates, while all remained susceptible to bacteriocin at 200 μL concentration. Conclusion: Our study highlights a significant MRSA carriage rate among HCWs and ICU patients, emphasizing the role of routine screening and hand hygiene in reducing MRSA transmission. While mupirocin resistance is increasing, bacteriocin demonstrates efficacy against MRSA, including mupirocin-resistant strains, suggesting its potential as an alternative therapeutic agent.