Study of Vancomycin Susceptibility in Methicillin-Resistant Staphylococcus aureus (MRSA)

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a major cause of healthcare-associated infections, posing significant treatment challenges due to its resistance to multiple antibiotics. Vancomycin, a glycopeptide antibiotic, is often considered the drug of choice for treating MRSA infections. However, the emergence of reduced vancomycin susceptibility in MRSA strains has raised concerns regarding the efficacy of this treatment. This study aimed to investigate the vancomycin susceptibility of MRSA isolates obtained from clinical samples in a tertiary care hospital. A total of 100 MRSA isolates were collected from various clinical specimens, including blood, wound, and respiratory tract samples. Vancomycin susceptibility was determined using the disk diffusion method and the broth microdilution method to identify Minimum Inhibitory Concentration (MIC) values. Among the 100 MRSA isolates, 96% showed susceptibility to vancomycin, with only 4% exhibiting intermediate resistance. No isolates demonstrated complete resistance to vancomycin. The study highlights that while vancomycin remains effective against most MRSA strains, the emergence of intermediate resistance indicates the need for continuous surveillance and the prudent use of antibiotics to prevent further resistance development.

Keywords: Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin susceptibility, Antimicrobial resistance, Hospital infections.