Changing Trends in the Microbiological spectrum and clinical presentation of Postcataract Endophthalmitis over a 23-year period.

Abstract

To characterize temporal changes in clinical severity, bacterial spectrum, and antimicrobial susceptibility in acute postcataract endophthalmitis over 23 years. Retrospective comparative cohort study. This study included 234 eyes of 234 patients presenting within 6 weeks after cataract surgery at 2 French tertiary referral centers. The historical cohort comprised 126 eyes managed from 2002 through 2007, and the recent cohort comprised 108 eyes managed from 2016 through 2025. Microbiological analyses included conventional cultures and 16S polymerase chain reaction on aqueous and/or vitreous samples. Antimicrobial susceptibility testing was performed on bacterial isolates. Baseline clinical severity, pathogen distribution, and resistance profiles were compared between cohorts. Pathogen distribution, cefuroxime susceptibility, methicillin resistance among staphylococci, and markers of clinical severity at presentation. Bacterial identification was obtained in 85 of 126 eyes (67.5%) in the historical cohort and 63 of 108 eyes (58.3%) in the recent cohort. Coagulase-negative staphylococci decreased from 38% to 25% of isolates, whereas Enterococcus faecalis increased from 2% to 10%; Gram-negative bacteria increased from 3.1% to 7.3%. Cefuroxime resistance increased from 26.0% (13/50) to 66.1% (adjusted OR, 3.75; 95% CI, 1.59-8.82; P = .003) of tested isolates. Among staphylococci, methicillin resistance increased from 30.3% to 75.0% (adjusted OR, 6.75; 95% CI, 1.99-22.83; P = .002), and multidrug-resistant phenotypes increased from 3.0% to 37.5% (P = .003). Eyes in the recent cohort had milder clinical presentation, with visual acuity of 20/400 or better in 29.0% versus 11.2%, visible fundus in 24.1% versus 9.6%, and pars plana vitrectomy performed in 51.9% versus 63.5%. Interpretation is limited by the retrospective design and incomplete susceptibility data. This retrospective comparative cohort study of 234 cases across two periods spanning 23 years was associated with a marked shift in the bacterial spectrum of acute postcataract endophthalmitis, with fewer coagulase-negative staphylococci and more Enterococcus faecalis isolates, alongside increased cefuroxime and methicillin resistance. Continued microbiological surveillance is warranted to guide empiric therapy and future prophylactic strategies.