Prevalence of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus (MRSA) in Laboratory Environment

Abstract

Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) are widely distributed in the world and pose a major public health problem. It is one of the important organisms that are implicated in hospital acquired infections. These pathogens are responsible for morbidity and mortality especially in  immunocompromised patients. In many, the organism is present as normal flora in healthy individuals. This study was undertaken to determine the prevalence of S. aureus and methicillin-resistant S. aureus in teaching laboratory environment. One hundred and twenty (120) samples were taken from sinks, working surface and floors from two laboratories. The samples were collected by using moistened sterile cotton swabs and directly inoculated on media. The isolated organisms were identified by standard procedures. S. aureus strains were tested for methicillin resistance on Mueller–Hinton agar plates by disc diffusion method. Of the 120 samples, S. aureus was isolated from 15 (12.5%) samples. Of these, 5 (33.33%) S. aureus isolates were methicillin resistant; three samples were from floor and sink of microbiology laboratory, while two samples were from working surface of biochemistry laboratory. The prevalence of S. aureus in laboratory environment that we studied was 18% and of these 33.33% (5 of 15 isolates) were MRSA. Possible sources include users as healthy nasal carriers by their acts like sneezing and the strains that were used for learning purpose. This study emphasizes the need for proper personal safety measures to be taken by users who are exposed to these areas to prevent infection by S. aureus and MRSA