Abstract
Purpose :
Eye drops for diagnostic purposes, such as mydriatics, local anesthetics, fluorescein etc. are commonly used in ophthalmology clinics. Because of the crowding in ophthalmology clinics, drop bottles empty in several days after they are opened. Although they run out in a very short period they can be contaminated.In this study we investigated contamination of the eye drops that are used in ophthalmology clinics.
Methods :
Samples were collected from eye drops just after opening of the bottle or in a week after they were opened. All samples were plated on blood agar, chocolate agar, MRS agar, M17 agar, calcium-lactate agar, plate-count agar, Sabouraud-dextrose agar, malt agar, brain heart agar and MacConkey agar. Presumptive isolates were identified by morphological, and biochemical tests, and confirmed by the VITEK system. Molecular characterization of isolated bacteria from eye drops were performed using sequencing analysis of the 16S rRNA gene. Sequences were compared with NCBI GenBank entries using the BLAST algorithm (http://www.ncbi.nlm.nih.gov/BLAST). Biofilm formation capacities of the isolates were assessed with microtiter plate method. We determined the antibiotic resistance of the isolates by the Kirby-Bauer disc diffusion test.
Results :
Isolates were obtained from both unused and used eye drops. 110 isolates were obtained frm eye drops. The most isolated bacteria were Coagulase negative Staphylococcus (CNS) spp. Other bacteria besides CNS were Pantoea sp, Micrococcus luteus, Sphingomonas paucimobilis, Gamella bergeri, Brevibacillus laterosporus, and some other bacillus species. Half of the isolates were found as biofilm producer. Biofilm formation was strong in half of the biofilm producer strains.
Conclusions :
Bacterial contamination can occur in very short period after bottles are opened. Interestingly we obtained bacterial isolates from unopened bottles. It may show that preservatives in the eye drops are not sufficient. Ophthalmologist should use these drops very carefully.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.