Bacterial spectrum and antimicrobial susceptibility and resistance patterns in adult chronic dacryocystitis: a systematic review and meta-analysis

Background Chronic dacryocystitis is common, but variable pathogens and antimicrobial susceptibility complicate treatment and surveillance. Objective To characterize the bacterial taxonomic composition in adults with chronic dacryocystitis, summarize the bacterial spectrum through pooled analyses of isolate-level proportions, and descriptively summarize evidence on antimicrobial susceptibility and resistance. Methods PubMed, Web of Science, Cochrane, Embase, and SinoMed were searched (1 January 2000–11 August 2026) for observational studies of adults aged ≥18 years reporting lacrimal sac pathogens or susceptibility outcomes. The JBI prevalence checklist assessed bias. Isolate-level bacterial proportions for taxa reported by ≥3 studies were pooled using a restricted maximum-likelihood random-effects model. PROSPERO: CRD420261435235. Results Ten studies (2005–2025) were included. Nine reported 1,413 patients; another chronic subgroup was estimated at 38–45 patients. Overall, 81 species-level, 52 genus-level, and 38 family-level taxa were identified. At the species level, Staphylococcus epidermidis had the highest pooled proportion of isolates at (20.4%, 95% CI: 9.1%–39.7%; I 2 = 88%). Staphylococcus aureus (14.7%, 95% CI: 7.1%–27.9%; I 2 = 92.7%) and Pseudomonas aeruginosa (7.13%, 95% CI: 2.98%–16.12%; I 2 = 82.6%) followed. The leading genera were Staphylococcus (41.2%, 95% CI: 26.3%–58%), Streptococcus (12.64%, 95% CI: 8.64%–18.13%), and Pseudomonas (8.02%, 95% CI: 4.13%–15.01%). The leading family was Staphylococcaceae (41.2%, 95% CI: 26.3%–58%; contributed by upward classification from the genus level). Streptococcaceae (12.64%, 95% CI: 8.64%–18.13%; similarly contributed) and Enterobacteriaceae (8.80%, 95% CI: 5.79%–13.15%) followed. Seven studies provided susceptibility data for 121 study-specific bacterial taxon–antimicrobial combinations, and four provided resistance data for 96 such combinations. inconsistent denominators, taxonomic levels, methods, and standards precluded pooling. Conclusions Across the 10 included studies from four Asian countries, staphylococci predominated among cultured bacterial isolates, while Gram-negative bacteria were also consistently reported. The limited evidence base, substantial between-study statistical heterogeneity, and low or very low certainty of evidence for many outcomes restrict generalizability. These context-dependent findings may inform local microbiological surveillance, but insufficiently standardized in vitro susceptibility and resistance evidence does not support a specific empirical treatment regimen. Systematic Review Registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420261435235 .