Browse AMR Genes

Explore antimicrobial resistance genes from the literature

ampR

ampicillin resistance gene

NCBI Pathogen Isolates

Bacterial genomes carrying this gene

NCBI Reference Gene Catalog

Known alleles and reference sequences

Protein entries specific to ampR

Browse AMR rules for ampR

Validation StatusSupported

Overview

Mechanism: D135N point mutation leads to upregulation of AmpC expression
Validation Method: CPRINS-FISH
Drug Classes: Ampicillin, Cephalosporin, Cefoxitin, Ceftriaxone, Cefotaxime, Cephalothin, Cefazolin, Beta-lactams, Quinolone, Aminoglycoside, Ceftazidime, Cefepime, Aztreonam, Imipenem, Meropenem, Piperacillin/tazobactam, Imipenem|Meropenem, Penicillin|Cephalosporin|Aztreonam, Ceftolozane|Tazobactam, Ciprofloxacin|Levofloxacin, Levofloxacin|Ciprofloxacin, Ceftazidime|Piperacillin/tazobactam, Ceftazidime|Cefepime|Ceftolozane/tazobactam|Ceftazidime/avibactam, CEPHALOSPORIN, Beta-lactam, Cefoxitin|Cefotaxime|Cefepime|Ertapenem|Imipenem|Meropenem, Ceftolozane/tazobactam|Ceftazidime-avibactam, Ceftazidime|Cefepime|Ticarcillin|Imipenem, Ceftazidime/avibactam, Cephalosporin|Penicillin, Ceftazidime|Cefepime|Aztreonam, Ticarcillin|Piperacillin|Cefepime|Ceftazidime|Aztreonam, Piperacillin, Aztreonam|Carbapenem|Cephalosporin, Ceftazidime-avibactam|Ceftolozane/tazobactam, Imipenem|Ampicillin
Organisms: Escherichia coli, Citrobacter freundii, Enterobacter cloacae, Pseudomonas aeruginosa, Klebsiella pneumoniae, Stenotrophomonas maltophilia, Pseudomonas aeruginosa PAO1, Enterococcus faecium
Geographic Location: Asia/South Pacific|Europe|Latin America|Middle East/Africa|North America, Italy
Papers: 34
Databases: Reslit
Mutations: 20

Mutations

Protein Change	Nucleotide Change	Mechanism	Organism	Resistance To	Database	Validation Status
G273E	-	-	-	Imipenem\|Meropenem	Reslit	Candidate
G154R	-	constitutive activation of ampC expression, ampC hyperproduction, transcriptional regulator AmpR, mutated	Pseudomonas aeruginosa	Penicillin\|Cephalosporin\|AztreonamCeftazidime\|Piperacillin/tazobactamCeftazidime\|Cefepime\|Ceftolozane/tazobactam\|Ceftazidime/avibactam+3 more	Reference Gene CatalogReslit	Confirmed

Papers34

1

Recognition of individual genes in diverse microorganisms by cycling primed in situ amplification.

PMID 16269764 · 2005

The study describes the development of CPRINS-FISH for detecting specific genes in bacterial cells, including the ampicillin resistance gene (ampR), chloramphenicol acetyltransferase gene (cat), and the rpoD gene. These genes were successfully detected in various bacterial species, demonstrating the effectiveness of the method for identifying individual genes in complex microbial communities.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: ampicillin resistance gene
Source Database: Reslit
Confers Resistance To: Ampicillin
Organisms Tested In: • Escherichia coli
Validation Method: CPRINS-FISH

2

Characterization of β-lactamase genes and their regulatory mechanisms in Gram-negative bacteria

PMID 20041868 · 2020

The study characterizes the chromosomal β-lactamase gene ampC and its regulatory genes ampR, ampD, ampE, and ampG in various Gram-negative bacteria, highlighting their roles in cephalosporin resistance.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: DNA-binding protein
Source Database: Reslit
Confers Resistance To: Cephalosporin
Organisms Tested In: • Escherichia coli
• Citrobacter freundii
• Enterobacter cloacae
• Pseudomonas aeruginosa
Validation Method: cloning and sequencing

3

Single or in combination antimicrobial resistance mechanisms of Klebsiella pneumoniae contribute to varied susceptibility to different carbapenems.

PMID 24265784 · 2013

The study identified that blaCTX-M-15, blaSHV-12, blaDHA-1, ampR, blaKPC-2, and blaNDM-1 are responsible for carbapenem resistance in Klebsiella pneumoniae. The loss of porins OmpK35 and OmpK36 combined with these genes contributed to resistance against various carbapenems.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: regulator
Source Database: Reslit
Confers Resistance To: CefoxitinCeftriaxoneCefotaximeCephalothinCefazolin
Organisms Tested In: • Klebsiella pneumoniae
Validation Method: genetic engineering and susceptibility testing

4

Role of Pseudomonas aeruginosa AmpR on β-lactam and non-β-lactam transient cross-resistance upon pre-exposure to subinhibitory concentrations of antibiotics.

PMID 24464693 · 2014

The study identifies AmpR and AmpC as key regulators in β-lactam and non-β-lactam transient cross-resistance in Pseudomonas aeruginosa upon pre-exposure to subinhibitory concentrations of antibiotics.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: global antibiotic resistance and virulence regulator
Source Database: Reslit
Confers Resistance To: Beta-lactamsQuinoloneAminoglycoside
Organisms Tested In: • Pseudomonas aeruginosa
Validation Method: mutant analysis and quantitative PCR

5

Multidrug Resistant Pseudomonas aeruginosa Causing Prosthetic Valve Endocarditis: A Genetic-Based Chronicle of Evolving Antibiotic Resistance.

PMID 29057280 · 2016

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: AmpC regulator
Source Database: Reslit
Mechanism: D135N point mutation leads to upregulation of AmpC expression
Confers Resistance To: CeftazidimeCefepimeAztreonam
Organisms Tested In: • Pseudomonas aeruginosa
Validation Method: sequencing

6

Culture-free bacterial detection and identification from blood with rapid, phenotypic, antibiotic susceptibility testing.

PMID 29467368 · 2018

The study demonstrates a culture-free method for rapid detection and identification of bacteria in blood, along with antibiotic susceptibility testing. It highlights the effectiveness of the FEED-based platform in detecting and identifying Escherichia coli and L. innocua, and in determining the susceptibility of E. coli strains to ampicillin and chloramphenicol.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: ampicillin resistance protein
Source Database: Reslit
Mechanism: confers resistance to ampicillin through the production of β-lactamase
Confers Resistance To: Ampicillin
Organisms Tested In: • Escherichia coli
Validation Method: demonstrated through the platform's ability to detect growth inhibition in the presence of ampicillin

7

Hospitalized Pets as a Source of Carbapenem-Resistance.

PMID 30574124 · 2018

The study identified carbapenem-resistant bacteria in hospitalized pets, including Acinetobacter radioresistens carrying blaNDM-1 and Acinetobacter baumannii carrying blaOXA-23. Mutations in the oprD gene were associated with carbapenem resistance in Pseudomonas aeruginosa, and S. maltophilia exhibited resistance to trimethoprim/sulfamethoxazole due to sul1 and sul2 genes.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: transcriptional regulator
Source Database: Reslit
Mechanism: regulation of L1 metallo-beta-lactamase
Confers Resistance To: ImipenemMeropenem
Organisms Tested In: • Stenotrophomonas maltophilia
Geographic Location: Italy
Validation Method: PCR and sequencing
Sequence Accession: PRJNA344732|PRJNA437120

8

Within-Host Adaptation Mediated by Intergenic Evolution in Pseudomonas aeruginosa.

PMID 30980662 · 2019

The study identifies intergenic mutations that enhance resistance to beta-lactam antibiotics by increasing the expression of ampR and ampC genes in Pseudomonas aeruginosa.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: global antibiotic resistance regulator
Source Database: Reslit
Organisms Tested In: • Pseudomonas aeruginosa PAO1
Validation Method: allelic replacement and MIC testing

9

Prosthetic valve endocarditis caused by Pseudomonas aeruginosa with variable antibacterial resistance profiles: a diagnostic challenge.

PMID 31208366 · 2019

The study identifies mutations in ampR, ampD, and oprD genes in Pseudomonas aeruginosa isolates causing prosthetic valve endocarditis, which are associated with variable resistance profiles to ceftazidime, piperacillin-tazobactam, and carbapenems.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: transcriptional regulator
Source Database: Reslit
Mechanism: regulates beta-lactamase expression
Confers Resistance To: CeftazidimePiperacillin/tazobactam
Organisms Tested In: • Pseudomonas aeruginosa
Validation Method: whole genome sequencing
Sequence Accession: CP035005|CP035006

10

Rapid and Ultrasensitive Detection of Mutations and Genes Relevant to Antimicrobial Resistance in Bacteria.

PMID 33552553 · 2021

The study presents a nanosensor-based assay for detecting antimicrobial resistance mutations and genes, including ampR D135G and G154R mutations and vanA, vanB, and vanD genes in Pseudomonas aeruginosa and Enterococcus faecium.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: transcriptional regulator
Source Database: Reslit
Confers Resistance To: Beta-lactams
Organisms Tested In: • Pseudomonas aeruginosa
Validation Method: RNA capture probes and cantilever nanosensor-based assay
Sequence Accession: NCBI GenBank: P. aeruginosa AE004091.2|NCBI GenBank: E. faecium AAAK03000003.1

11

Rapid Decline of Ceftazidime Resistance in Antibiotic-Free and Sublethal Environments Is Contingent on Genetic Background.

PMID 35291010 · 2022

The study identifies mutations in ampR and rpoB that contribute to the decline of ceftazidime resistance in Pseudomonas aeruginosa under antibiotic-free and sublethal tobramycin environments. These mutations result in reduced β-lactamase activity and restored RpoB functionality, leading to decreased resistance.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: LysR-type transcriptional regulator
Source Database: Reslit
Mechanism: regulates the expression of the β-lactamase AmpC
Confers Resistance To: Ceftazidime
Organisms Tested In: • Pseudomonas aeruginosa
Validation Method: whole-genome sequencing and β-lactamase activity measurements
Sequence Accession: NCBI BioProject PRJNA714523

12

Insight into the impacts and mechanisms of ketone stress on the antibiotic resistance in Escherichia coli.

PMID 35771331 · 2022

The study found that exposure to methylisobutanone (MIBK) affects the antibiotic resistance in Escherichia coli, particularly highlighting the role of the ampR gene in conferring ampicillin resistance.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: ampicillin resistance
Source Database: Reslit
Mechanism: confers resistance to ampicillin
Confers Resistance To: Ampicillin
Organisms Tested In: • Escherichia coli
Validation Method: qPCR and transformation experiments

13

Cefepime-taniborbactam activity against antimicrobial-resistant clinical isolates of Enterobacterales and Pseudomonas aeruginosa: GEARS global surveillance programme 2018-22.

PMID 39287999 · 2024

Cefepime-taniborbactam showed potent in vitro activity against Enterobacterales and P. aeruginosa, particularly effective against isolates with carbapenemase genes such as blaIMP, blaNDM, and blaVIM, as well as those with mutations in ftsI, ompK35, and ompK36.

Gene Information

Gene Name: ampR
Allele: ampR
Encodes: regulator of AmpC production
Source Database: Reslit
Confers Resistance To: Cefepime
Organisms Tested In: • Pseudomonas aeruginosa
Geographic Location: Asia/South Pacific|Europe|Latin America|Middle East/Africa|North America
Validation Method: molecular testing by WGS or PCR and Sanger sequencing
Sequence Accession: NCBI BioProject PRJNA1012345|NCBI BioProject PRJNA734525|NCBI BioProject PRJNA734526