Microbial safety implications of in-use topical diagnostic ophthalmic medications in eye clinics in Ghana

PURPOSE: To determine the microbial contaminants and its clinical importance in topical diagnostic ophthalmic medications (cycloplegics/mydriatics and miotics) in eye clinics in Ghana. METHOD: A cross-section of eye clinics was sampled for the diagnostic agents (Atropine, Phenylephrine, Tropicamide and Cyclopentolate, Pilocarpine). 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 testing was also performed to ascertain the clinical importance of the isolated microbes. RESULTS: A total of 113 samples were obtained, from which 334 bacteria were isolated which included Bacilli spp. 91(27.25%), Coagulase Negative Staphylococci spp. 59(17.66%), Moraxella spp. 47(14.07%), Staphylococcus aureus 41(12.27%), Streptococcus spp. 21(6.29%), Klebsiella spp. 20(5.99%), Pseudomonas spp. 13(3.89%), Proteus spp. 12(3.59%), Escherichia coli. 12 (3.59%), Serratia spp. 10(2.99%), Shigella spp. 7(2.09%), Salmonella spp. 1(0.3%). There were 96 isolated fungal contaminants mainly Penicillium spp. 41(42.71%), Cephalosporium spp. 19(19.79%), Cladosporium spp. 15(15.63%), Aspergillus spp. 13(13.54%), Cercospora spp. 8(8.33%). The diagnostic agent with the most bacteria contamination was Phenylephrine 90 (26.95%) and the least being Pilocarpine 49 (14.67%). Also, the diagnostic agent with the most fungal contamination was Cyclopentolate 29 (30.2%) and the least was Tropicamide and Pilocarpine with 15 (15.63%) each. Gentamicin and Ciprofloxacin were the only antibiotics that showed 100% activity against all the bacterial isolates. Fungal contaminants were more susceptible to Ketoconazole as compared to Fluconazole. CONCLUSION: Topical diagnostic ophthalmic preparations used in clinical settings in Ghana are contaminated with clinically important bacteria and fungi.