Browse AMR Genes

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mrcB

penicillin-binding protein 1b

NCBI Pathogen Isolates

Bacterial genomes carrying this gene

NCBI Reference Gene Catalog

Known alleles and reference sequences

Protein entries specific to mrcB

Browse AMR rules for mrcB

Validation StatusSupported

Overview

Mechanism: inhibition by cefsulodin
Validation Method: deletion and complementation experiments
Drug Classes: Beta-lactams, Cefoxitin, Cefotaxime, Ceftazidime, Imipenem, Meropenem, Colistin, Cefiderocol
Organisms: Escherichia coli, Pseudomonas spp., Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae
Geographic Location: Norway|China
Papers: 6
Databases: Reslit
Mutations: 3

Mutations

Protein Change	Nucleotide Change	Mechanism	Organism	Resistance To	Database	Validation Status
S459A	-	-	Acinetobacter baumannii	Colistin	Reslit	Candidate
R363C	-	-	Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae	Cefiderocol	Reslit	Candidate
-	T135G	-	Escherichia coli	-	Reslit

Papers6

1

Sub-inhibitory cefsulodin sensitization of E. coli to β-lactams is mediated by PBP1b inhibition.

PMID 23139798 · 2012

The study shows that deletion of the mrcB gene, which encodes PBP1b, increases sensitivity to β-lactam antibiotics. Cefsulodin at sub-inhibitory concentrations mimics the effect of PBP1b deletion, enhancing β-lactam sensitivity.

Gene Information

Gene Name: mrcB
Allele: mrcB
Encodes: penicillin-binding protein 1b
Source Database: Reslit
Mechanism: inhibition by cefsulodin
Confers Resistance To: Beta-lactams
Organisms Tested In: • Escherichia coli
Validation Method: deletion and complementation experiments

2

Cephem Potentiation by Inactivation of Nonessential Genes Involved in Cell Wall Biogenesis of β-Lactamase-Producing Escherichia coli.

PMID 27956425 · 2017

Inactivation of dapF and mrcB genes in β-lactamase-producing E. coli restored susceptibility to cefoxitin and reduced MICs of other cephems, demonstrating their potential as helper drug targets for enhancing cephem activity.

Gene Information

Gene Name: mrcB
Allele: mrcB
Encodes: penicillin-binding protein 1b
Source Database: Reslit
Mechanism: inactivation of nonessential gene involved in cell wall biogenesis
Confers Resistance To: CefoxitinCefotaximeCeftazidime
Organisms Tested In: • Escherichia coli
Validation Method: comparison of MICs in wild type and mutant harboring plasmid

3

Antibiotic Resistance and Phylogeny of Pseudomonas spp. Isolated over Three Decades from Chicken Meat in the Norwegian Food Chain.

PMID 33498315 · 2021

The study identified several AMR genes and mutations in Pseudomonas spp. isolated from chicken meat in Norway, including beta-lactamases, efflux pumps, and genes involved in resistance to aminoglycosides, fluoroquinolones, and colistin.

Gene Information

Gene Name: mrcB
Allele: mrcB
Encodes: penicillin-binding protein
Source Database: Reslit
Mechanism: reduced affinity for beta-lactam antibiotics
Confers Resistance To: ImipenemMeropenem
Organisms Tested In: • Pseudomonas spp.
Geographic Location: Norway|China
Validation Method: whole-genome sequencing
Sequence Accession: PRJNA685056