# Genotypic and phenotypic characterisation of asymptomatic bacteriuria (ABU) isolates displaying bacterial interference against multi-drug resistant uropathogenic E. Coli

## TL;DR

This study explores bacteria in the bladder that don't cause symptoms but may protect against harmful E. coli infections.

## Contribution

The study identifies new genotypic and phenotypic traits of asymptomatic E. coli isolates that may be useful for bacterial interference.

## Key findings

- Two ABU isolates lacked antibiotic resistance and virulence genes compared to a known ABU strain.
- Isolates belonged to phylogroups A, B2, and D, with B2 being most common.
- The study highlights how genetic traits influence suitability for therapeutic bacterial interference.

## Abstract

Escherichia coli can colonise the urogenital tract of individuals without causing symptoms of infection, in a condition referred to as asymptomatic bacteriuria (ABU). ABU isolates can protect the host against symptomatic urinary tract infections (UTIs) by bacterial interference against uropathogenic E. coli (UPEC). The aim of this study was to investigate the genotypic and phenotypic characteristics of five ABU isolates from midstream urine samples of adults. Comparative genomic and phenotypic analysis was conducted including an antibiotic resistance profile, pangenome analysis, and a putative virulence profile. Based on the genome analysis, the isolates consisted of one from phylogroup A, three from phylogroup B2, and one from phylogroup D. Two of the isolates, PUTS 58 and SK-106-1, were noted for their lack of antibiotic resistance and virulence genes compared to the prototypic ABU strain E. coli 83,972. This study provides insights into the genotypic and phenotypic profiles of uncharacterised ABU isolates, and how relevant fitness and virulence traits can impact their potential suitability for therapeutic bacterial interference.

The online version contains supplementary material available at 10.1007/s00203-024-04114-0.