Clinical and Bacteriological Specificities of Escherichia coli Bloodstream Infections From Biliary Portal of Entries.

This article focuses on the clinical and genomic characteristics of Escherichia coli strains responsible for bloodstream infections (BSIs) originating from biliary tract infections compared to nonbiliary digestive and urinary tract infections. Analysis of 770 E. coli BSI episodes and whole genome sequencing revealed that biliary strains resemble commensal E. coli in phylogroup distribution, sequence type diversity, and carry fewer virulence-associated genes, despite having antibiotic resistance levels similar to other pathogenic strains. Clinically, patients with biliary BSIs had comparable initial severity but experienced lower mortality rates than those with nonbiliary digestive BSIs, a difference potentially attributable to the role of biliary drainage alongside antibiotic treatment. These findings suggest that biliary tract infections represent a distinct clinical and microbiological entity within E. coli BSIs, emphasizing the importance of differentiating them in patient management and prognosis studies.