Prevalence and antibiotic susceptibility patterns of nasal bacterial isolates from some students in a tertiary institution in Delta State

Abstract

The prevalence and antibiotic susceptibility patterns of bacterial isolates from the nose of subjects in a tertiary institution in Delta State, Nigeria, were investigated. Nasal samples of one hundred (100) subjects (both males and females) were collected with the aid of sterile swab sticks. Seventy eight percent (78%) of collected samples yielded growth on the nutrient agar media incubated at 37^oC for 24 h. Standard microbiological assays were carried out to characterize the bacterial isolates. The Kirby-Bauer disk diffusion method was employed for antibiotic sensitivity testing of the confirmed isolates following Clinical and Laboratory Standards Institutes (CLSI) Guidelines. The following organisms were identified: Staphylococcus aureus, 43.6%; Klebsiella species, 24.4%; Citrobacter species, 12.8%; Proteus species, 7.7%; and Staphylococcus epidermidis, 11.5%. The prevalences of Gram-negative and Gram positive organisms were 55.1% and 45.9% respectively. The isolated bacteria demonstrated varying susceptibility patterns to the antibiotics with the Gram negative microorganisms being more susceptible to pefloxacin and chloramphenicol while the Gram positive micro-organisms showed highest susceptibility to pefloxacin and ciprofloxacin. Gram negative organisms showed the lowest sensitivity to amoxicillin while Gram positive bacterial isolates showed the lowest susceptibility to cefuroxime and amoxicillin. This study also revealed, that S. aureus was the most frequent nasal bacteria in the subjects studied. This calls for a more rational antibiotic usage to avert the recurrence of refractory microbial strains that constitute a great threat to the global human health.

Keywords: Susceptibility, Resistance pattern, Pathogenicity, Antibiotic, sensitivity