Microbiology and antimicrobial resistance in biliary tract infections including acute and post-ERCP cholangitis: a systematic review and meta-analysis.

BACKGROUND

Organisms cultured from bile in biliary tract infection, and their resistance, vary widely between settings, and pooled estimates to guide empirical therapy are lacking.

OBJECTIVE

Estimate bile-culture yield, organism distribution, and resistance.

DESIGN

Systematic review and random-effects meta-analysis of PubMed and reference lists.

SETTING

Reports spanned nine countries across Asia, Europe, Africa, and North America.

METHODS

We extracted ductal-bile culture data from observational studies published from 2015 to 2025 of biliary infection/cholangitis; noninfectious, gall bladder-only, microbiome-only, and nonextractable reports were excluded. DerSimonian-Laird models, subgroup analysis, and JBI appraisal were used.

MAIN OUTCOME MEASURE: Culture yield; secondary organism proportions and resistance.

SAMPLE SIZE: 5147 patients (97% retrospective; 3% prospective); organisms: 35 267 observations.

RESULTS

Yield was 77.3% (95% CI, 67.8-84.6); Gram-negative organisms 69.8% (65.6-73.7), E. coli, 27.4% (23.5-31.7), K. pneumoniae, 14.1% (12.3-16.2).

HETEROGENEITY: I2=86.0%-97.7%; all P<.001.

RISK OF BIAS: Fourteen reports were low risk, two moderate; exclusions minimally changed estimates.

CONCLUSION

Bile-culture yield was high and Gram-negative organisms, particularly E. coli and K. pneumoniae, predominated, but estimates were highly heterogeneous and resistance could not be pooled; culture-directed therapy guided by local antibiograms is therefore preferable to a universal empirical regimen.

LIMITATIONS: PubMed-only/open-access search, retrospective designs, inconsistent definitions, one dominant dataset.

REGISTRATION: Retrospectively registered on OSF (89wqs; DOI: 10.17605/OSF.IO/89WQS).