Antibiotic Susceptibility Profile and Plasmid Analysis of Micro-Organisms Associated with Ocular Infections

Abstract

Background: This study was undertaken to determine the antimicrobial susceptibility profile and plasmid analysis of micro-organisms associated with ocular infections. Methods: Ocular specimens were collected from 500 patients. Subsequent identification was done based on morphology and biochemical tests. Susceptibility pattern of the isolates was done using the disk diffusion method. The presence of plasmids was determined using the agar gel electrophoresis technique. Plasmid curing was carried out by treating the MAR isolates with sodium dodecyl sulfate at concentration of 10%. Results: Conjunctivitis was the most prevalent ocular infection of 105 (39.8%). S. aureus was the most prevalent pathogen 63 (23.9%) followed by CoNS 36 (13.6%). S. aureus was 100% sensitive to vancomycin and chloramphenicol. CoNS was also 100% sensitive to ciprofloxacin, vancomycin, and chloramphenicol. K pneumoniae was 100% sensitive to gentamicin and amoxicillin-clavulanic acid while N. gonorrhoeae was 100% sensitive to gentamicin, ciprofloxacin, ceftriaxone, amoxicillin-clavulanic acid, and cefotaxime. The overall MAR bacteria was 38 (16.2%). Plasmid analysis revealed the presence of 1–3 plasmid bands of sizes 6.21–16.22 Kbp from the MAR isolates. Plasmid curing revealed that the gene coding for resistant seen in this study was plasmid mediated. Conclusions: The prevalence of ocular infection was high with conjunctivitis being the dominant. The dominant bacteria species were S. aureus and CoNS. The overall MAR bacteria proportion was relatively high. The presence of plasmids was responsible for the resistance of the isolates to antibiotics.