Service interruption on Monday 11 July from 12:30 to 13:00: all the sites of the CCSD (HAL, EpiSciences, SciencesConf, AureHAL) will be inaccessible (network hardware connection).
Skip to Main content Skip to Navigation
Journal articles

Modification of outer membrane permeability and alteration of LPS in veterinary enterotoxigenic Escherichia coli

Abstract : Enterotoxigenic Escherichia coli (ETEC) is a worrying cause of diarrhoea in calves and the drug multiresistance phenotype concerning various antibiotic families are of concern. Resistance mechanisms associated with envelope changes (porin expression, efflux pump overexpression, lipolysaccahride (LPS) modification) were studied in 14 ETEC isolates selected for their resistance. We performed determinations of (i) antimicrobials Minimal Inhibitory Concentrations with or without the efflux pump inhibitor phenylalanine arginine β-naphthylamide; (ii) colistin and polymyxin MICs with and without EDTA, (iii) intracellular accumulation of chloramphenicol in presence of an energy uncoupler of pump energy, (iv) and immunodetection of porins and evaluation of porin trimers thermostability. Results indicated that 9 strains presented significant efflux mechanisms overexpression, among them 8 were resistant to colistin and polymyxin B due to a modification of LPS structure as evidenced by EDTA effect and silver staining electrophoresis. The high resistant strains to colistin and polymyxin exhibited identical LPS patterns. Studies of E. coli porins indicated that the majority of strains didn't show modification in their amount, however analysis of porin thermostability showed that porin trimers of some resistant strains were relatively heat-labile, suggesting a misassembly of the functional trimer. The multidrug resistance (MDR) phenotypes detected in these selected ETEC corresponded to association of LPS modifications, abordive assembly of porin trimers and active efflux which drastically alter the antibiotic activity currently used to combat enteric infections caused by this pathogen.
Document type :
Journal articles
Complete list of metadata

Cited literature [16 references]  Display  Hide  Download
Contributor : emmanuelle rosa Connect in order to contact the contributor
Submitted on : Tuesday, June 2, 2020 - 3:28:51 PM
Last modification on : Wednesday, November 3, 2021 - 5:50:00 AM
Long-term archiving on: : Wednesday, December 2, 2020 - 2:58:58 PM


Files produced by the author(s)




Anne Davin-Regli, Véronique Guérin-Faublée, Jean-Marie Pagès. Modification of outer membrane permeability and alteration of LPS in veterinary enterotoxigenic Escherichia coli. Research in Veterinary Science, Elsevier, 2019, 124, pp.321-327. ⟨10.1016/j.rvsc.2019.04.011⟩. ⟨hal-02649532⟩



Record views


Files downloads