Phenotypic and Genotypic Detection of Methicillin Resistant Staphylococcus aureus in Health Care Workers and Its Containment in a Tertiary Care Hospital, in South India

Abstract

MRSA causes nosocomial and community based infections. It is associated with significant mortality and morbidity. Resistance in MRSA is encoded by mecA gene. Anterior nares are the ecological niche of Staphylococcus aureus. HCWs who are colonized with MRSA, act as agents of cross contamination of hospital and community acquired MRSA. Treating MRSA infections is a therapeutic challenge as it is resistant to beta lactam group of drugs. Therefore, there is a need for rapid and accurate detection of MRSA carriage in HCWs and to understand its antibiotic susceptibility pattern.The objective of the present study is to estimate the occurrence of MRSA in HCWs, using phenotypic and genotypic methods. A prospective study for six months was conducted after obtaining Institutional Ethical Committee clearance. Anterior nasal swabs of those HCWs who gave informed consent were taken processed for culture and sensitivity as per standard protocol. To detect MIC for oxacillin, E-strip method was used. mecA gene detection was done by PCR. A total of 300 HCWs were sampled.14.66% (44/300) of the isolates were identified as Staphylococcus aureus, of which 10 isolates were detected as MRSA. The overall isolation rate of MRSA is 3.33 %(10/300). MRSA carriage was high amongst nurses (5/59, 8.47%), followed by doctors (4/105, 3.80%).Antibiotic sensitivity pattern showed that highest resistance was to penicillin (75%) followed by amoxiclav (70.45 %).9 MRSA isolates were detected as mecA gene positive by PCR. MRSA carriers were decontaminated successfully with 2% mupirocin ointment and 2% chlorhexidine shampoo. This study reiterates the need for rapid and accurate identification of HCWs who have nasal colonization with MRSA, for reinforcing hospital infection control measures and decontamination protocol. This will help prevent the spread of MRSA in our community.