Browse AMR Genes

Explore antimicrobial resistance genes from the literature

pexA

phenicol efflux MFS transporter PexA

NCBI Pathogen Isolates

Bacterial genomes carrying this gene

NCBI Reference Gene Catalog

Known alleles and reference sequences

Protein entries specific to pexA

Browse AMR rules for pexA

Validation StatusConfirmed2+ DBs

Overview

Mechanism: Increased efflux
Validation Method: transposon mutagenesis and MIC testing
Drug Classes: CHLORAMPHENICOL, PHENICOL, FLORFENICOL, Chloramphenicol, Florfenicol
Organisms: uncultured bacterium Ak20-3, Escherichia coli
Geographic Location: Alaska, China
Alleles: 2
Papers: 2
Databases: Card DatabaseReference Gene CatalogResFinder DatabaseReslit

Allele Variants2

Allele	Database	Papers	Drug Classes	Organisms	Countries	Years	Sequence Accession	Protein Accession
PexA	Card DatabaseReference Gene CatalogResFinder DatabaseReslit	5	CHLORAMPHENICOL, PHENICOL +3	uncultured bacterium Ak20-3 +1	Alaska, China

Papers2

1

Novel florfenicol and chloramphenicol resistance gene discovered in Alaskan soil by using functional metagenomics.

PMID 20543056 · 2010

Gene Information

Gene Name: pexA
Allele: PexA
Encodes: phenicol efflux MFS transporter PexA
Source Database: ResFinder Database
Mechanism: Increased efflux
Confers Resistance To: CHLORAMPHENICOLPHENICOLFLORFENICOL
Organisms Tested In: • uncultured bacterium Ak20-3
Sequence Accession: HM537013.1
Protein Accession: ADI87853.1
Notes: MFS transporter

2

Novel florfenicol and chloramphenicol resistance gene discovered in Alaskan soil by using functional metagenomics.

PMID 20543056 · 2010

Gene Information

Gene Name: pexA
Allele: PexA
Encodes: phenicol efflux MFS transporter PexA
Source Database: Card Database
Mechanism: Increased efflux
Confers Resistance To: CHLORAMPHENICOLPHENICOLFLORFENICOL
Organisms Tested In: • uncultured bacterium Ak20-3
Sequence Accession: HM537013.1
Protein Accession: ADI87853.1
Notes: MFS transporter

3

Novel florfenicol and chloramphenicol resistance gene discovered in Alaskan soil by using functional metagenomics.

PMID 20543056 · 2010

Gene Information

Gene Name: pexA
Allele: pexA
Source Database: ResFinder Database
Mechanism: Increased efflux
Confers Resistance To: CHLORAMPHENICOLFLORFENICOL
Organisms Tested In: • uncultured bacterium Ak20-3
Sequence Accession: HM537013
Notes: MFS transporter

4

Novel florfenicol and chloramphenicol resistance gene discovered in Alaskan soil by using functional metagenomics.

PMID 20543056 · 2010

Gene Information

Gene Name: pexA
Allele: PexA
Encodes: phenicol efflux MFS transporter PexA
Source Database: Reference Gene Catalog
Mechanism: Increased efflux
Confers Resistance To: CHLORAMPHENICOLPHENICOLFLORFENICOL
Organisms Tested In: • uncultured bacterium Ak20-3
Sequence Accession: HM537013.1
Protein Accession: ADI87853.1
Notes: MFS transporter

5

Novel florfenicol and chloramphenicol resistance gene discovered in Alaskan soil by using functional metagenomics.

PMID 20543056 · 2010

A novel florfenicol and chloramphenicol resistance gene, pexA, was identified in Alaskan soil using functional metagenomics. The gene encodes a major facilitator superfamily drug exporter that confers resistance to phenicols.

Gene Information

Gene Name: pexA
Allele: PexA
Encodes: drug resistance transporter
Source Database: Reslit
Confers Resistance To: ChloramphenicolFlorfenicol
Organisms Tested In: • Escherichia coli
Geographic Location: Alaska
Validation Method: transposon mutagenesis and MIC testing
Sequence Accession: HM537013

6

Antimicrobial multidrug resistance of Escherichia coli from broiler farms in Zhanjiang, China.

PMID 41183086 · 2025

The study identified multiple AMR genes in E. coli isolates from broiler farms in Zhanjiang, China, including bla TEM, bla AIM, pexA, aadA1, ant(3")-I, sul2, and sul3, which were associated with multidrug resistance to various antibiotics.

Gene Information

Gene Name: pexA
Allele: PexA
Encodes: Efflux pump
Source Database: Reslit
Confers Resistance To: FlorfenicolChloramphenicol
Organisms Tested In: • Escherichia coli
Geographic Location: China
Validation Method: PCR and drug susceptibility testing

7

Gene Information

Gene Name: pexA
Allele: pexA
Encodes: major facilitator superfamily (MFS) antibiotic efflux pump
Source Database: Card Database
Mechanism: antibiotic efflux
Organisms Tested In: • uncultured bacterium Ak20-3
Sequence Accession: HM537013.1
Protein Accession: ADI87853.1
Notes: ARO:3004666