Microbiological study of methicillin-resistant Staphylococcus aureus isolated from wound samples at a tertiary care hospital, Central India

Abstract

Background: Staphylococcus aureus continues to be a dangerous pathogen for both community-acquired as well as hospital-associated infections. S. aureus resistant to methicillin were reported soon after its introduction in October 1960. Methicillin-resistant S. aureus (MRSA) is now endemic in India. MRSA has recently emerged as a major nosocomial pathogen worldwide with a significant morbidity and mortality.
Materials and Methods: This study was thus undertaken to characterize MRSA isolates, isolated from wound samples from a tertiary care teaching hospital in Central India and to also probe antibiotic susceptibility of its clinical isolates.
Results: About 120 MRSA isolates from various clinical samples such as pus swabs and aspirates, blood, urine, sputum, and endotracheal tube aspirates were collected and processed in the laboratory for various tests. Of 120 isolates subjected to gelatin liquefaction test with appropriate controls, 104 were found to be positive while 16 were tested negative. Majority of the hospital-associated MRSA (HA-MRSA) patients were in the age group of >50 years of age 42 (35%) followed by the 41–50 years of age group 26 (21.7%). The age in the HA-MRSA group varied from 18 to 75 years with mean age of 41.2 ± 22.29. Majority of the HA-MRSA infections presented as cellulitis (41.9%), followed by abscess (28.9%) and post-operative wound discharge (23.8%), whereas most of the community-associated-MRSA infections presented as abscesses (83.5%), followed by furuncle (9.6%), and cellulitis and carbuncle (2.8% each). Among 120 isolates subjected to alkaline phosphatase test, 114 were found to be phosphatase positive while 6 being phosphatase negative.
Conclusion: Our study is a preamble to enable epidemiologists to understand the nature of MRSA isolates in this part of India. There is a need to study epidemiology of such infections. Robust antimicrobial stewardship and strengthened infection control measures are required to prevent spread and reduce emergence of resistance.