Nasal carriage status of staphylococcus aureus amongst people working in the diagnostic microbiology laboratory of a coastal Karnataka medical college

Background: S. aureus is one of the most common human pathogens and is capable of causing a wide range of infections. Although primary S. aureus infections are not familiar, a great deal of the virulence from this bacterium occurs through cross-infection by spread from patient to patient in hospitals and other institutional settings. In contrast, healthy individuals can be carriers of the organism but have a minimal risk of contracting an invasive infection caused by S.aureus, but Aims and Objectives: To determine the nasal carriage status of the people working in the microbiology diagnostic laboratory with emphasis on MRSA. Materials and Method: Swabs of both anterior nares of consenting persons were taken with a sterile swab & processed within 2 hours. Swabs were inoculated on Mannitol Salt Agar. The organisms grown were identified as S.aureus by using standard tests. Antibiotic susceptibility testing was carried on by a modified Kirby-Bauer method, whereas cefoxitin (30μg) disc was used to know the MRSA. Result: A total of 80 healthcare workers with the age range between 20 and 60 years were screened. Out of 80 participants, 25 were nasal carriers of S.aureus. The S.aureus isolates were 100% sensitive to Gentamicin, Teicoplanin, Vancomycin and Cefoxitin, 80% susceptible to Ciprofloxacin and Linezolid, and 76% to Amoxyclav, 96% resistant to Penicillin, 84% Erythromycin and 76% Ceftriaxone. Discussion: Nasal carriage rate of S.aureus amongst people working in the diagnostic microbiology laboratory of our institution was 31.25%. Of the 25 isolates of S.aureus, none of them were MRSA. So overall MRSA carriage rate was 0%.