Unusual microbiological presentations in polymicrobial post-operative endophthalmitis and their clinical correlations

Purpose: To report the clinical course, microbiological spectrum and visual outcomes of three cases of post-operative endophthalmitis caused by unusual combination of micro-organisms. Methods: Retrospective review of medical charts at a tertiary eye care centre over a period of 1 year, of subjects with post-operative endophthalmitis and more than one microbiological isolate. Results: We report 3 cases with unusual combination of microorganisms. In case 1, two organisms (Burkholderia cepacia and Aeromonas veronii, from the vitreous cavity and capsular bag, respectively) with an identical antibiotic sensitivity pattern were found, while in case 2, the organisms (Streptococcus pneumoniae and Sphingomonas paucimobilis, from cornea and vitreous cavity, respectively) isolated had different sensitivity patterns. In case 3, two different strains of the same organism (Enterococcus faecalis) were found. Cases 1 and 2 achieved good anatomical and visual outcomes, while in case 3, vision remained poor despite a good anatomical outcome. Conclusion: Unusual combinations of organisms in post-operative endophthalmitis can introduce unique clinical characteristics and should specifically be considered in atypical clinical presentations, poor response to standard therapy and unusual recurrence patterns.