Nasal Carriage of Staphylococcus Aureus among Healthy Students in a Nigerian University

Abstract

Background: Staphylococcus aureus (S. aureus) nasal carriage is potential source for their continuous spread as well as risk factor for subsequent infections. Studies on S. aureus nasal carriage are important in determining the epidemiology of staphylococcal infections and a guide to infection control and preventive measures. Aim of the study: The present study was conducted to investigate the carriage prevalence and antibiotic susceptibility of S. aureus among students studying Medical Laboratory Science at the University of Jos. Materials and methods: Two hundred and forty one (241) nasal swab specimens were obtained from Medical laboratory science students of the University of Jos. Swabs were plated on Mannitol salt agar (MSA), culture plates were incubated at 37oC for 18-24hours. After incubation S. aureus isolates were identified by their characteristic yellowish colony on MSA. Standard inocula were prepared by adjusting density of saline suspension of S.aureus to 0.5 McFarland’s standard. Antibiotic sensitivity was performed on Mueller Hinton agar by disc diffusion method. Zone diameter was read according to Clinical and Laboratory Standards Institute (CLSI) interpretative break point (CLSI 2004). Results: This study has established an overall carriage prevalence of 37.3%. The carriage rate was more in female 51 (40.4%) than male students 39 (33.9%). Regarding year of study 300level students 53 (46.4%) recorded the highest carriage rate while the least was noted among 500 level 8 (21.6%). Antibiotic susceptibility testing was performed using eight (8) antibiotics disc, all the isolates tested (n=90) were susceptible to vancomycin 90 (100.0%). Conclusion: There is high prevalence of S. aureus nasal carriage among Medical Laboratory Students at University of Jos. We recommend that studies on other potential sources like health care workers, medicine students, nursing students etc. be carried out in our setting.