Bacterial and fungal flora of conjunctiva of patients presenting with cataract and their seasonal variation in Northern India

Abstract

The objective of this study was to study the microbial flora (bacterial and fungal) of the conjunctival sac of patients presenting with cataracts at a tertiary care hospital in North India. This observational cross-sectional study included 320 eyes from 238 patients presenting with cataracts. Three conjunctival swabs were collected from each eye and analyzed for the presence of aerobes, anaerobes, and fungal growth. The data were analyzed using R statistical environment 4.0 software, along with the R Commander plugin “EZR.” Kruskal–Wallis rank sum test. In addition, the Fisher exact test was conducted, considering P < 0.05 as statistically significant. A total of 75.63% (242) of conjunctival sacs were culture-positive, with a predominance of bacterial growth. On the other hand, 24.37% (78) of conjunctival sacs were sterile. Common commensals isolated included Staphylococcus epidermidis (34.06%), Staphylococcus aureus (10.0%), Propionibacterium spp. (7.5%), and Corynebacterium spp. (5.31%). There were 23 (10%) Gram-negative cultures, whereas three fungi were isolated, all of which were Candida spp. The highest total growths were observed in age group 2 (51–65 years); however, no statistically significant correlation existed between age groups and growths. Season 1, characterized by temperatures between 10° and 15°, exhibited maximum growths. The most growths were coagulase-negative staphylococci (CONS). Our study of North Indian eyes revealed that 75.63% of healthy conjunctival sacs showed positive cultures, mainly CONS, with no seasonal trend. Given CONS’s prevalence in post-cataract endophthalmitis, routine pre-operative conjunctival swabs could guide prophylaxis and lower rates of post-operative endophthalmitis.