Colonization and Antibiogram of Stapylococcus Species Isolated from Apparently Healthy Students in a Tertiary Institution in Nigeria

Staphylococci are the most abundant skin-colonizing bacteria and the most important causes of nosocomial and community- associated skin infections. This study investigated the prevalence and antibiogram of Staphylococcus species among healthy students in relation to gender and site of isolation. A cross-sectional study in which 503 participants were randomly selected was conducted among apparently healthy students from the University of Benin. Moistened sterile cotton swabs were aseptically used to collect samples from the anterior nares, nose, axilla and ear of the volunteers and cultured by standard bacteriological procedures. Isolates which showed positive colonial morphology were processed for direct gram stain, microscopy and biochemical tests. Antibiotic susceptibility profile of the isolates to selected antibiotics commonly used in the locality was determined using Kirby-Bauer disc diffusion method. A total of 560 isolates were obtained, of which 332 (59.23%) isolates were Staphylococcus aureus, 170 (30.36%) were Staphylococcus epidermidis and 57 (10.18%) isolates were Staphylococcus lugdunensis. Staphylococcal colonization rate was 53.21% in males and 46.79% in females. The most frequently colonized site from the volunteers was the nose with 203 (36.3%) isolates obtained, then the anterior nares 126 (22.5%), the axilla 124 (22.14%), and then the ears with a total of 107 (19.1%) isolates. Pefloxacin, Gentamicin and Ciprofloxacin gave the highest activity (82.04% - 94.71%) while Amoxicillin, Ampicillin/ Cloxacillin and Cefuroxime showed the least activity (3.45-51.76%). The findings highlight the colonization potential of both coagulase-positive and coagulase-negative Staphylococcus species among healthy individuals and emphasize the need for continuous surveillance to mitigate the risk of community-acquired antimicrobial resistance.