| Accession | ARO:3000263 |
| CARD Short Name | marA |
| Definition | In the presence of antibiotic stress, E. coli overexpresses the global activator protein MarA, which besides inducing MDR efflux pump AcrAB, also down- regulates synthesis of the porin OmpF. |
| AMR Gene Family | General Bacterial Porin with reduced permeability to beta-lactams, resistance-nodulation-cell division (RND) antibiotic efflux pump |
| Drug Class | tetracycline antibiotic, disinfecting agents and antiseptics, penem, phenicol antibiotic, rifamycin antibiotic, penam, cephamycin, glycylcycline, cephalosporin, carbapenem, monobactam, fluoroquinolone antibiotic |
| Resistance Mechanism | reduced permeability to antibiotic, antibiotic efflux |
| Efflux Component | efflux pump complex or subunit conferring antibiotic resistance |
| Efflux Regulator | protein(s) and two-component regulatory system modulating antibiotic efflux |
| Resistomes with Perfect Matches | Escherichia colig+p+wgs, Klebsiella pneumoniaewgs, Shigella boydiig+wgs, Shigella dysenteriaeg+wgs, Shigella flexnerig+wgs, Shigella sonneig+wgs |
| Resistomes with Sequence Variants | Citrobacter amalonaticusg+wgs, Citrobacter freundiig+wgs, Citrobacter koserig+wgs, Citrobacter portucalensisg+wgs, Citrobacter werkmaniig+wgs, Citrobacter youngaeg+wgs, Cronobacter condimentig+wgs, Cronobacter dublinensisg+wgs, Cronobacter malonaticusg+wgs, Cronobacter sakazakiig+wgs, Cronobacter turicensiswgs, Cronobacter universalisg+wgs, Enterobacter asburiaeg+wgs, Enterobacter cancerogenusg+wgs, Enterobacter chengduensisg+wgs, Enterobacter cloacaeg+wgs, Enterobacter hormaecheig+p+wgs, Enterobacter kobeig+wgs, Enterobacter roggenkampiig+wgs, Escherichia albertiig+wgs, Escherichia colig+p+wgs, Escherichia fergusoniig+wgs, Escherichia marmotaeg+wgs, Klebsiella aerogenesg+wgs, Klebsiella huaxiensisg+wgs, Klebsiella michiganensisg+wgs, Klebsiella oxytocag+wgs, Klebsiella pneumoniaeg+p+wgs, Klebsiella quasipneumoniaeg+wgs, Kosakonia arachidisg+wgs, Leclercia adecarboxylatag+wgs, Raoultella planticolag+wgs, Salmonella bongorig+wgs, Salmonella entericag+wgs, Serratia marcescenswgs, Shigella boydiig+wgs, Shigella dysenteriaeg+wgs, Shigella flexnerig+wgs, Shigella sonneig+wgs |
| Classification | 32 ontology terms | Show + process or component of antibiotic biology or chemistry + antibiotic molecule + mechanism of antibiotic resistance + reduced permeability to antibiotic [Resistance Mechanism] + beta-lactam antibiotic + determinant of antibiotic resistance + cephem + protein modulating permeability to antibiotic + tetracycline antibiotic [Drug Class] + antibiotic efflux [Resistance Mechanism] + disinfecting agents and antiseptics [Drug Class] + General Bacterial Porin (GBP) + penem [Drug Class] + phenicol antibiotic [Drug Class] + efflux pump complex or subunit conferring antibiotic resistance [Efflux Component] + rifamycin antibiotic [Drug Class] + penam [Drug Class] + cephamycin [Drug Class] + glycylcycline [Drug Class] + cephalosporin [Drug Class] + carbapenem [Drug Class] + monobactam [Drug Class] + General Bacterial Porin with reduced permeability to beta-lactams [AMR Gene Family] + triclosan [Antibiotic] + cefalotin [Antibiotic] + ampicillin [Antibiotic] + chloramphenicol [Antibiotic] + rifampin [Antibiotic] + resistance-nodulation-cell division (RND) antibiotic efflux pump [AMR Gene Family] + tetracycline [Antibiotic] + tigecycline [Antibiotic] + fluoroquinolone antibiotic [Drug Class] |
| Parent Term(s) | 4 ontology terms | Show + regulates porin OmpF + protein modulating permeability to antibiotic + regulates AcrAB-TolC + protein(s) and two-component regulatory system modulating antibiotic efflux [Efflux Regulator] |
| Publications | Cohen SP, et al. 1988. J Bacteriol 170(12): 5416-5422. marA locus causes decreased expression of OmpF porin in multiple-antibiotic-resistant (Mar) mutants of Escherichia coli. (PMID 2848006) Alekshun MN and Levy SB. 1997. Antimicrob Agents Chemother 41(10): 2067-2075. Regulation of chromosomally mediated multiple antibiotic resistance: the mar regulon. (PMID 9333027) Randall LP and Woodward MJ. 2002. Res Vet Sci 72(2): 87-93. The multiple antibiotic resistance (mar) locus and its significance. (PMID 12027588) |
Prevalence of marA among the sequenced genomes, plasmids, and whole-genome shotgun assemblies available at NCBI or IslandViewer for 413 important pathogens (see methodological details and complete list of analyzed pathogens). Values reflect percentage of genomes, plasmids, genome islands, or whole-genome shotgun assemblies that have at least one hit to the AMR detection model. Default view includes percentages calculated based on Perfect plus Strict RGI hits. Select the checkbox to view percentages based on only Perfect matches to AMR reference sequences curated in CARD (note: this excludes resistance via mutation as references in protein variant models are often wild-type, sensitive sequences).
| Species | NCBI Chromosome | NCBI Plasmid | NCBI WGS | NCBI GI |
|---|---|---|---|---|
| Citrobacter amalonaticus | 100% | 0% | 89.09% | 0% |
| Citrobacter freundii | 100% | 0% | 50.1% | 0% |
| Citrobacter koseri | 100% | 0% | 49.55% | 0% |
| Citrobacter portucalensis | 100% | 0% | 62.16% | 0% |
| Citrobacter werkmanii | 100% | 0% | 61.54% | 0% |
| Citrobacter youngae | 100% | 0% | 100% | 0% |
| Cronobacter condimenti | 100% | 0% | 100% | 0% |
| Cronobacter dublinensis | 100% | 0% | 100% | 0% |
| Cronobacter malonaticus | 100% | 0% | 85.45% | 0% |
| Cronobacter sakazakii | 100% | 0% | 92.15% | 0% |
| Cronobacter turicensis | 0% | 0% | 83.33% | 0% |
| Cronobacter universalis | 100% | 0% | 66.67% | 0% |
| Enterobacter asburiae | 100% | 0% | 70.75% | 0% |
| Enterobacter cancerogenus | 100% | 0% | 100% | 0% |
| Enterobacter chengduensis | 100% | 0% | 84% | 0% |
| Enterobacter cloacae | 98.21% | 0% | 73.16% | 0% |
| Enterobacter hormaechei | 98.56% | 0.06% | 66.9% | 0% |
| Enterobacter kobei | 100% | 0% | 68.12% | 0% |
| Enterobacter roggenkampii | 100% | 0% | 62.23% | 0% |
| Escherichia albertii | 94.29% | 0% | 59.35% | 0% |
| Escherichia coli | 67.68% | 0.06% | 61.52% | 0% |
| Escherichia fergusonii | 98.36% | 0% | 50% | 0% |
| Escherichia marmotae | 100% | 0% | 70.83% | 0% |
| Klebsiella aerogenes | 100% | 0% | 79.66% | 0% |
| Klebsiella huaxiensis | 100% | 0% | 66.67% | 0% |
| Klebsiella michiganensis | 100% | 0% | 68.88% | 0% |
| Klebsiella oxytoca | 100% | 0% | 74.37% | 0% |
| Klebsiella pneumoniae | 99.11% | 0.01% | 57.15% | 0% |
| Klebsiella quasipneumoniae | 99.16% | 0% | 73.29% | 0% |
| Kosakonia arachidis | 100% | 0% | 100% | 0% |
| Leclercia adecarboxylata | 100% | 0% | 60.47% | 0% |
| Raoultella planticola | 100% | 0% | 94.87% | 0% |
| Salmonella bongori | 100% | 0% | 94.74% | 0% |
| Salmonella enterica | 95.52% | 0% | 80.96% | 0% |
| Serratia marcescens | 0% | 0% | 0.13% | 0% |
| Shigella boydii | 93.33% | 0% | 94.44% | 0% |
| Shigella dysenteriae | 100% | 0% | 90% | 0% |
| Shigella flexneri | 99% | 0% | 81.21% | 0% |
| Shigella sonnei | 100% | 0% | 93.5% | 0% |
Model Type: protein homolog model
Model Definition: Protein Homolog Models (PHM) detect protein sequences based on their similarity to a curated reference sequence, using curated BLASTP bitscore cut-offs. Protein Homolog Models apply to all genes that confer resistance through their presence in an organism, such as the presence of a beta-lactamase gene on a plasmid. PHMs include a reference sequence and a bitscore cut-off for detection using BLASTP. A Perfect RGI match is 100% identical to the reference protein sequence along its entire length, a Strict RGI match is not identical but the bit-score of the matched sequence is greater than the curated BLASTP bit-score cutoff, Loose RGI matches have a bit-score less than the curated BLASTP bit-score cut-off.
Bit-score Cut-off (blastP): 230