Nasal colonization with mrsa in patients undergoing cardiac surgery.

Abstract

ABSTRACT: Introduction: Patients colonised with MRSA are at an increased risk of developing post surgical infections and the implications are greater in vascular and orthopedic surgeries involving prosthetic implants. Preoperative screening for nasal colonisation and decolonisation reduces the risk for the development of such infections. Aims and objectives: To assess the rate of nasal colonisation with MRSA and their antibiotic susceptibility pattern among patients undergoing cardiac surgery in our centre. Methods and material: Anterior nasal swabs from 69 patients undergoing cardiac valve replacement surgeries, that were sent to the Department of Microbiology, as part of routine preoperative screening for nasal colonisation by MRSA, were included in the study. Screening for MRSA was done by disc diffusion method using cefoxitin disc. Antibiotic sensitivity testing of the MRSA isolates was done by modified Kirby Bauer disc diffusion method. Vancomycin sensitivity was assessed by macro broth dilution method. Results: Ten percent of patients were found to harbour MRSA in their anterior nares. Multidrug resistance was observed in over 44% of isolates. All the isolates were sensitive to vancomycin. Over 55% of the isolates showed vancomycin MIC in the range of 1-2µg/ml. Conclusion: Our study revealed a high rate of MDR among MRSA colonising the anterior nares. This is of great concern, as the infection caused by such isolates is not only difficult to treat but also can increase the morbidity and mortality. We recommend preoperative screening for nasal colonization by MRSA among all the patients undergoing high risk surgeries.