Implications of two-component systems EnvZ/OmpR and BaeS/BaeR in in vitro temocillin resistance in Escherichia coli

© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy..

BACKGROUND: BaeS/BaeR is a two-component system of Escherichia coli that controls the expression of porins and efflux pumps. Its role in beta-lactam resistance is limited.

OBJECTIVES: To study the role of baeS/baeR two-component system in temocillin resistance in E. coli.

METHODS: E. coli strain BW25113 and single-gene deletion mutants related to two-component systems were collected from the KEIO collection. Double-gen deletion mutants were generated. Temocillin-resistant mutant frequencies were determined at 32 mg/L. E. coli BW25113 mutants were selected by selective pressure from serial passages. Biological costs were analysed by growth curves. Genomes of the generated mutants were sequenced. The expression level of the mdtA, mdtB, mdtC, acrD and tolC in the ΔbaeS mutant was determined by RT-PCR (with/without temocillin exposure).

RESULTS: The frequency of temocillin mutants ranged from 2.12 × 10-8 to 4.51 × 10-8 in single-porin mutants. No mutants were recovered from E. coli BW25113 (>10-9). Selection of temocillin-resistant variants by serial passage yielded mutants up to 128 mg/L. Mutations were found in the baeS gene. Temocillin MICs ranged from 4 to 32 mg/L (highest MICs for ΔbaeS and ΔompR). The efflux pumps mdtA, mdtB, mdtC and acrD pumps were overexpressed 3-10-fold in the presence of temocillin in ΔbaeS compared to control.

CONCLUSIONS: Mutations in the sensor histidine kinase, baeS, may be involved in temocillin resistance through the expression of the efflux pumps mdtABC and acrD. In addition, the low mutation rate may be a good predictor of temocillin activity.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:79

Enthalten in:

The Journal of antimicrobial chemotherapy - 79(2024), 3 vom: 01. März, Seite 641-647

Sprache:

Englisch

Beteiligte Personen:

Pérez-Palacios, Patricia [VerfasserIn]
Rodríguez-Ochoa, José Luis [VerfasserIn]
Velázquez-Escudero, Ana [VerfasserIn]
Rodríguez-Baño, Jesús [VerfasserIn]
Rodríguez-Martínez, José Manuel [VerfasserIn]
Pascual, Álvaro [VerfasserIn]
Docobo-Pérez, Fernando [VerfasserIn]

Links:

Volltext

Themen:

03QB156W6I
52664-04-7
BaeR protein, E coli
Cadaverine
Escherichia coli Proteins
Journal Article
L90BEN6OLL
Monodansylthiacadaverine
Penicillins
Temocillin
Trans-Activators

Anmerkungen:

Date Completed 04.03.2024

Date Revised 04.03.2024

published: Print

Citation Status MEDLINE

doi:

10.1093/jac/dkae021

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM367950588