Nasal Carriage of Staphylococcus Aureus in Different Age Groups Among Healthy School Children and its Antimicrobial Susceptibility Pattern

Abstract

Introduction: Staphylococcus aureus (S.aureus) is associated with increased risk for acquiring invasive disease. There exists an increasing prevalence of resistant community acquired S.aureus infections due to the nasal colonisation of S.aureus and Methicillin-Resistant S.aureus (MRSA) worldwide. Aim: To evaluate the prevalence rate of S.aureus and MRSA nasal colonisation among healthy school children and to determine its antibiotic susceptibility rate of the S.aureus isolates. Materials and Methods: The community based cross-sectional study was conducted among 344 school going children of 5-16 years of age. Samples were obtained from the anterior nares from each child and cultured on Blood Agar (BA) and Mannitol Salt Agar (MSA). Antibiotic susceptibility pattern of S.aureus was done by Kirby-Bauer disc diffusion method. MRSA detection was done through Cefoxitin 30 µg discs along with MIC for Oxacillin and Vancomycin simultaneously according to Clinical Laboratory Standard Institute (CLSI). Results: Of the 344 children, 26 (7.55%) were found to be with nasal carriage for S.aureus of which MRSA was found to be in 12 (3.48%) isolates. S.aureus isolates exhibited resistance to multiple classes of antibiotics including Penicillin (100%), Co-trimoxazole (50%), Ciprofloxacin (15.4%), Vancomycin (7.7%), Clindamycin (7.7%), Gentamycin (7.7%). No resistance to Linezolid was observed. Conclusion: A relatively high rate of nasal carriage of S.aureus in children of age group 5-10 years was observed when compared to children of age group 11-15 years. With the risk involved transmission of infection and resistance to many classes of antibiotics among S.aureus strains exists and hence, emphasis needs to be laid to design control measures, continued surveillance and its eradication.

Keywords

• cefoxitin
• community associated-methicillin resistant s.aureus
• nasal colonisation