Browse AMR Genes

Explore antimicrobial resistance genes from the literature

emrab

drug transporter

NCBI Pathogen Isolates

Bacterial genomes carrying this gene

NCBI Reference Gene Catalog

Known alleles and reference sequences

Protein entries specific to emrab

Browse AMR rules for emrab

Validation StatusSupported

Overview

Mechanism: inducible by metals (chromate and manganese) and antibiotics (ampicillin and chloramphenicol)
Validation Method: cloning in E. coli + drug resistance testing
Drug Classes: Ampicillin, Carbenicillin, Chloramphenicol, Nalidixic acid, Tetracycline, Colistin, Tobramycin, Cephalosporins, Aztreonam, Carbapenems, Penicillin, Aminoglycoside, Rifamycins, Fluoroquinolone, Macrolide, Nitroimidazole, Phenicol, Aminocoumarin, Beta-lactams
Organisms: Escherichia coli, Staphylococcus aureus LZ-01, Pseudomonas aeruginosa, Acinetobacter baumannii, Cedecea neteri SSMD04, Salmonella enterica serovar Typhimurium, Salmonella Gallinarum, Acinetobacter spp.
Geographic Location: Colombia, Europe, Europe|global, Krasnodar Krai, Russia|Russia, Norway +2 more
Alleles: 2
Papers: 11
Databases: Reslit

Allele Variants2

Allele	Database	Papers	Drug Classes	Organisms	Countries	Years	Sequence Accession	Protein Accession
emrAB	Reslit	9	Ampicillin, Carbenicillin +16	Escherichia coli +6	Europe, Norway, Europe\|global, Colombia, South Korea, Krasnodar Krai, Russia\|Russia	2001, 2016, 2018, 2020, 2021, 2022, 2023, 2024, 2025

Papers11

1

Analysis of a complete library of putative drug transporter genes in Escherichia coli.

PMID 11566977 · 2001

The study identified 20 genes in Escherichia coli that confer resistance to various antimicrobial agents, including novel drug resistance determinants such as yceE, yceL, yidY, ydgFE, yegO, cusA, and ybjYZ. Additionally, several previously known genes were found to have broader resistance spectra than previously reported.

Gene Information

Gene Name: emrab
Allele: emrAB
Encodes: drug transporter
Source Database: Reslit
Organisms Tested In: • Escherichia coli
Validation Method: cloning in E. coli + drug resistance testing

2

Multidrug resistance operon emrAB contributes for chromate and ampicillin co-resistance in a Staphylococcus strain isolated from refinery polluted river bank.

PMID 27722066 · 2016

The emrAB operon in Staphylococcus aureus LZ-01 confers co-resistance to chromate and ampicillin, as evidenced by gene knockout and complementation experiments showing reduced resistance in mutants.

Gene Information

Gene Name: emrab
Allele: emrAB
Encodes: efflux pumps belonging to the multidrug resistance (MDR) family
Source Database: Reslit
Mechanism: inducible by metals (chromate and manganese) and antibiotics (ampicillin and chloramphenicol)
Confers Resistance To: Ampicillin
Organisms Tested In: • Staphylococcus aureus LZ-01
Geographic Location: Europe
Validation Method: RNA-seq and qRT-PCR methods, gene knockout, and induction tests

3

Two Regulators, PA3898 and PA2100, Modulate the Pseudomonas aeruginosa Multidrug Resistance MexAB-OprM and EmrAB Efflux Pumps and Biofilm Formation.

PMID 30297364 · 2018

The study identifies PA3898 and PA2100 as novel regulators that modulate the multidrug resistance efflux pumps MexAB-OprM and EmrAB, as well as biofilm formation in Pseudomonas aeruginosa.

Gene Information

Gene Name: emrab
Allele: emrAB
Encodes: multidrug efflux pump
Source Database: Reslit
Mechanism: activated by PA3898 and PA2100
Confers Resistance To: CarbenicillinChloramphenicolNalidixic acid
Organisms Tested In: • Pseudomonas aeruginosa
Validation Method: mutant analysis and MIC testing

4

Whole Genome Sequencing and Characterization of Multidrug-Resistant (MDR) Bacterial Strains Isolated From a Norwegian University Campus Pond.

PMID 32625184 · 2020

The study identifies multiple AMR genes and mutations in ESBL-producing bacteria from Norwegian freshwater environments, highlighting the presence of multidrug-resistant strains with resistance to various antibiotics including beta-lactams, fluoroquinolones, and sulfonamides.

Gene Information

Gene Name: emrab
Allele: emrAB
Encodes: efflux pump
Source Database: Reslit
Confers Resistance To: AmpicillinTetracycline
Organisms Tested In: • Escherichia coli
Geographic Location: Norway
Validation Method: whole genome sequencing
Sequence Accession: CP042878-CP042881|CP042882-CP042884|CP042885-CP042892|CP044402-CP044406|CP047609-CP047613|CP043406-CP043413|JAAAYF000000000|JAAAYE000000000

5

Antimicrobial Resistance in Multidrug-Resistant Pathogens: Focus on Polymyxin Resistance Mechanisms

PMID 32784516 · 2023

This review discusses the antibacterial activity and mechanisms of resistance to polymyxins, focusing on their interaction with bacterial membranes and the genetic basis of resistance.

Gene Information

Gene Name: emrab
Allele: EmrAB
Source Database: Reslit
Confers Resistance To: Colistin
Organisms Tested In: • Acinetobacter baumannii
Geographic Location: Pakistan|Taiwan|Germany|Spain|Korea|Thailand|Dubai|India|Italy|Czech Republic|China|Brazil|Australia
Validation Method: expression analysis

6

Biofilms as Promoters of Bacterial Antibiotic Resistance and Tolerance.

PMID 33374551 · 2020

This review discusses how biofilms contribute to bacterial antibiotic resistance and tolerance through mechanisms such as the extracellular matrix (ECM) barrier, physiological heterogeneity, and efflux pumps. It highlights the role of biofilms in protecting bacteria from antibiotics by creating heterogeneous environments and facilitating horizontal gene transfer.

Gene Information

Gene Name: emrab
Allele: EmrAB
Encodes: efflux pump component
Source Database: Reslit
Mechanism: efflux pump
Confers Resistance To: Tobramycin
Organisms Tested In: • Escherichia coli
Validation Method: mutant analysis

7

Genomic Insights into Drug Resistance Determinants in Cedecea neteri, A Rare Opportunistic Pathogen.

PMID 34442820 · 2021

The study identifies multiple beta-lactamase genes, including a novel CMY/ACT-type AmpC beta-lactamase and several metallo-beta-lactamases, as well as multidrug efflux pumps in Cedecea neteri, highlighting its resistance mechanisms against various antibiotics.

Gene Information

Gene Name: emrab
Allele: emrAB
Encodes: Multidrug efflux pump
Source Database: Reslit
Mechanism: efflux of antibiotics
Confers Resistance To: Colistin
Organisms Tested In: • Cedecea neteri SSMD04
Geographic Location: Europe|global
Validation Method: homology search and sequence analysis
Sequence Accession: CP009451.1|CP009458.1|CP009459.1|CP011077.1|NZ_CP009451.1|NZ_CP011077.1

8

Analysis of multidrug efflux transporters in resistance to fatty acid salts reveals a TolC-independent function of EmrAB in Salmonella enterica.

PMID 35421142 · 2022

EmrAB contributes to resistance against fatty acid salts in Salmonella enterica, functioning independently of TolC.

Gene Information

Gene Name: emrab
Allele: emrAB
Encodes: efflux pump
Source Database: Reslit
Organisms Tested In: • Salmonella enterica serovar Typhimurium
• Escherichia coli
Validation Method: deletion and overexpression strains, MIC testing

9

Genomic Characterization and Genetic Profiles of Salmonella Gallinarum Strains Isolated from Layers with Fowl Typhoid in Colombia.

PMID 37107581 · 2023

The study identified 26 chromosomal resistance genes in Salmonella Gallinarum strains, primarily encoding efflux pumps, and point mutations in gyrase genes (gyrA and gyrB) associated with quinolone resistance. The gyrB mutation S464T was frequently found in Colombian strains.

Gene Information

Gene Name: emrab
Allele: emrAB
Encodes: MFS efflux pump
Source Database: Reslit
Confers Resistance To: CephalosporinsAztreonamCarbapenemsPenicillinAminoglycosideRifamycinsFluoroquinoloneMacrolideNitroimidazolePhenicolTetracyclineAminocoumarin
Organisms Tested In: • Salmonella Gallinarum
Geographic Location: Colombia
Validation Method: genomic analysis
Sequence Accession: PRJNA483415

10

Prevalence of antibiotic-resistant Acinetobacter spp. on soil and crops collected from agricultural fields in South Korea.

PMID 38752113 · 2024

The study identified several antibiotic resistance genes in Acinetobacter spp. isolated from agricultural fields in South Korea, including emrAB, cat, craA, and aadA, which confer resistance to colistin, chloramphenicol, and streptomycin.

Gene Information

Gene Name: emrab
Allele: emrAB
Encodes: efflux pump
Source Database: Reslit
Confers Resistance To: Colistin
Organisms Tested In: • Acinetobacter spp.
Geographic Location: South Korea
Validation Method: PCR and MIC analysis
Sequence Accession: CP133067|CP133074|CP133075|CP133068|CP133069|CP133070|CP133072|CP133073

11

Genetic Basis of Multiple Antibiotic Resistance of Pathogenic Escherichia coli Strains Isolated from Livestock Complexes in Krasnodar Krai, Russia.

PMID 41516189 · 2025

The study identified multiple antibiotic resistance genes in E. coli strains isolated from livestock in Russia, including β-lactamases, efflux pumps, and tetracycline resistance genes, contributing to multidrug resistance.

Gene Information

Gene Name: emrab
Allele: emrAB
Encodes: efflux pump component
Source Database: Reslit
Mechanism: efflux pump
Confers Resistance To: Beta-lactamsTetracyclineFluoroquinoloneAminoglycoside
Organisms Tested In: • Escherichia coli
Geographic Location: Krasnodar Krai, Russia|Russia
Validation Method: whole-genome sequencing and phenotypic resistance testing
Sequence Accession: BioProject PRJNA887444