Polymicrobial catheter biofilms sustain susceptible Enterococcus faecalis and Escherichia coli during β-lactam treatment
- 1Uppsala university
Abstract
Broad-spectrum {beta}-lactam exposure can select for Enterococcus-dominated urinary communities in catheterized intensive-care patients, even when co-colonizing Escherichia coli remains susceptible. We investigated paired E. faecalis and E. coli isolates recovered before and after piperacillin-tazobactam (TZP) treatment using a catheter biofilm model and showed that their survival depends on mutualism and biofilm-dependent persistence. Without antibiotics, E. faecalis reduced E. coli biofilm formation yet promoted pre-attachment co-aggregation and reorganized mixed-biofilm architecture on the catheter. Despite TZP susceptibility and the absence of resistance determinants, catheter-associated biofilms and biofilm-dispersed cells survived concentrations 250- to 1000-fold above their MICs, whereas planktonic cells were eliminated. Survivors retained susceptibility but showed delayed regrowth, consistent with a transient persister-like state. In the post-treatment pair, each species sustained the other during recovery, coinciding with a nonsynonymous substitution in the enterococcal surface adhesin Esp. These findings show that antagonistic and cooperative interactions can coexist within catheter biofilms and enable susceptible polymicrobial communities to withstand {beta}-lactam treatment without {beta}-lactam resistance.
Related
- Enterococcus faecalis-derived lactic acid suppresses macrophage activation to facilitate persistent and polymicrobial wound infections
- Genomic insight into Enterococcus faecium biofilm formation isolated from catheter associated urinary tract infection
- Multimodal imaging reveals surface degradation of voice prosthesis implants resulting from colonisation by polymicrobial biofilms
- Microbiota-constrained bacterial density limits phage infection in the gut and allows persistence of susceptible cells
- FmdNspPred: A computational model for prediction of foot-and-mouth disease virus exposure of the susceptible animals using 2B NSP-ELISA data
BibTeX
@misc{karlsson2026polymicrobial,
title = {{Polymicrobial catheter biofilms sustain susceptible Enterococcus faecalis and Escherichia coli during β-lactam treatment}},
author = {P. A. Karlsson and M. Skinkyte and C. Bolin and H. Zhou and H. Abenayake and E. Joffre and W. Xia and J. D. Jarhult and H. Wang},
howpublished = {bioRxiv},
year = {2026},
month = aug,
doi = {10.64898/2026.08.31.748328},
url = {https://www.biorxiv.org/content/10.64898/2026.08.31.748328v1},
note = {CC BY-ND},
}
RIS
TY - UNPB
TI - Polymicrobial catheter biofilms sustain susceptible Enterococcus faecalis and Escherichia coli during β-lactam treatment
AU - P. A. Karlsson
AU - M. Skinkyte
AU - C. Bolin
AU - H. Zhou
AU - H. Abenayake
AU - E. Joffre
AU - W. Xia
AU - J. D. Jarhult
AU - H. Wang
PY - 2026
DA - 2026/08/31
PB - bioRxiv
DO - 10.64898/2026.08.31.748328
UR - https://www.biorxiv.org/content/10.64898/2026.08.31.748328v1
AB - Broad-spectrum {beta}-lactam exposure can select for Enterococcus-dominated urinary communities in catheterized intensive-care patients, even when co-colonizing Escherichia coli remains susceptible. We investigated paired E. faecalis and E. coli isolates recovered before and after piperacillin-tazobactam (TZP) treatment using a catheter biofilm model and showed that their survival depends on mutualism and biofilm-dependent persistence. Without antibiotics, E. faecalis reduced E. coli biofilm formation yet promoted pre-attachment co-aggregation and reorganized mixed-biofilm architecture on the catheter. Despite TZP susceptibility and the absence of resistance determinants, catheter-associated biofilms and biofilm-dispersed cells survived concentrations 250- to 1000-fold above their MICs, whereas planktonic cells were eliminated. Survivors retained susceptibility but showed delayed regrowth, consistent with a transient persister-like state. In the post-treatment pair, each species sustained the other during recovery, coinciding with a nonsynonymous substitution in the enterococcal surface adhesin Esp. These findings show that antagonistic and cooperative interactions can coexist within catheter biofilms and enable susceptible polymicrobial communities to withstand {beta}-lactam treatment without {beta}-lactam resistance.
ER -