Topical Ocular Anesthetics Harbour Clinically Important Microbes
Purpose: The study was to determine clinically important microbial contaminants of topical ocular anesthetic medications used in eye centers in Ghana.
Methods: A cross-section of eye clinics was sampled for the topical ocular anesthetic agents. Standard laboratory procedures and protocols were observed in culturing the samples on different Agars. Microscopy and various biochemical tests were performed to identify microbial species. Antimicrobial susceptibility tests were also performed to ascertain the clinical importance of the isolated microbes.
Results: A total of 27 anesthetic agent were obtained (which consisted 15 Proparacaine and 12 Amethocaine), from which 87 bacteria were isolated which included Bacilli spp. 26(29.89%), Coagulase Negative Staphylococci spp. 17(19.54%), Moraxella spp. 17(19.54%), Staphylococcus aureus 8(9.19%), Streptococcus spp. 3(3.45%), Klebsiella spp. 3(3.45%), Pseudomonas spp. 1(1.15%), Proteus spp. 7(8.05%), Escherichia coli. 2(2.30%), and Shigella spp. 3(3.45%). There were 22 isolated fungal contaminants mainly Penicillium spp. 7(31.82%), Cephalosporium spp. 5(22.73%), Aspergillus spp 4(18.18%), Cercospora spp. 2(9.09%), and Cladosporium spp. 4(18.18%). The anesthetic agent with the most bacterial contamination was Proparacaine 44(50.57%) followed by Amethocaine 43(49.43%). Also, both agents were equally contaminated with fungus 11(50.0%) in each. Gentamicin was the only antibiotics that showed 100% activity against all the bacterial isolates. Fungal contaminants were more susceptible to Ketoconazole as compared to Fluconazole (p≤0.05).
Conclusion: Topical ocular anesthetic preparations used in clinical setings in Ghana are contaminated with clinically important microbes as the isolated bacteria were susceptible only to Gentamicin and fungi to Ketoconazole and Fluconazole.
Keywords: Anesthetics, Ocular infections, Amethocaine, Proparacaine