Plasmid profiles as an epidemiological marker of MRSA in patients and medical personnel

In order to study the epidemiology of methicillin-resustant Staphylococcus aureus (MRSA) in patients and medical personnel, the incidences of Staphylococcus aureus (S.aureus) and MRSA in 262 healthy (medical and non-medical) personnel and 152 patients (51 admitted burn cases from Burn unit and 101 cases from Out Patient Department (OPD)) from 3 governmental hospitals were determined. 116 strains of MRSA were isolated from nasal cavities and hands of the medical personnel and also from wounds of the patients. 51% of burn patients carried MRSA in wounds Only 5.9% of the OPD patients carried the organisms. The minimal inhibitory concentrations of methicillin against all MRSA isolates were >256 mcg/ml. All of the isolates were susceptible to vancomycin. The susceptibility of MRSA against 18 antimicrobial agents were also tested. Both antibiogram and plasmid profile of MRSA were determined for the use as epidemiologic marker (s). Only plasmid profile analysis was recommended. This method was shown to be simple, reproducible and have good discriminatory power. 16 different plasmid profile of MRSA was demonstrated. Only 4 common profiles were isolated from both group of the patients.