Browse AMR Genes
Explore antimicrobial resistance genes from the literature
Explore antimicrobial resistance genes from the literature
trimethoprim-resistant dihydrofolate reductase DfrB9
Overview
| Protein Change | Nucleotide Change | Mechanism | Organism | Resistance To | Database | Validation Status |
|---|---|---|---|---|---|---|
| F98Y | - | confers resistance | Staphylococcus aureus, Staphylococcus epidermidis | trimethoprimtrimethoprim sulfamethoxazole | Reslit | Candidate |
| F99Y | - | Target modification, dihydrofolate reductase DfrB | Staphylococcus aureus | trimethoprim | Reference Gene CatalogResFinder DatabaseReslit | Confirmed |
| L21V | - | Target modification, dihydrofolate reductase DfrB | Staphylococcus aureus | trimethoprim | Reference Gene CatalogResFinder DatabaseReslit | Confirmed |
| L41F | - | Target modification, dihydrofolate reductase DfrB | Staphylococcus aureus | trimethoprim | Reference Gene CatalogResFinder DatabaseReslit | Confirmed |
| F123L | - | - | Staphylococcus aureus | trimethoprim | Reslit | Candidate |
| A135T | - | dihydrofolate reductase DfrB | Staphylococcus aureus | trimethoprim | Reference Gene CatalogReslit | Confirmed |
| V76A | - | - | Staphylococcus aureus | trimethoprim | Reslit | Candidate |
| I83V | - | - | Staphylococcus aureus | trimethoprim | Reslit | Candidate |
| I97T | - | - | - | trimethoprim | Reslit | Candidate |
| V72E | - | - | - | trimethoprim | Reslit | Candidate |
| W38F | - | impedes the formation of functional tetramer, resulting in 10- and 40-fold weaker effective binding to DHF and NADPH, respectively, and a 100-fold reduced catalytic turnover | E. coli | trimethoprim | Reslit | Candidate |
| H149R | - | - | Staphylococcus aureus | trimethoprimtrimethoprim sulfamethoxazole | Reslit | Candidate |
| L40I | - | - | Staphylococcus aureus | trimethoprim sulfamethoxazole | Reslit | Candidate |
| F92L | - | - | Staphylococcus aureus | trimethoprim sulfamethoxazole | Reslit | Candidate |
| T96I | - | - | Staphylococcus aureus | trimethoprim sulfamethoxazole | Reslit | Candidate |
| L141P | - | - | Staphylococcus aureus | trimethoprim sulfamethoxazole | Reslit | Candidate |
| H31N | - | Target modification, dihydrofolate reductase DfrB | Staphylococcus aureus | trimethoprim | Reference Gene CatalogResFinder Database | Confirmed |
| N60I | - | Target modification, dihydrofolate reductase DfrB | Staphylococcus aureus | trimethoprim | Reference Gene CatalogResFinder Database | Confirmed |
| F99S | - | Target modification, dihydrofolate reductase DfrB | Staphylococcus aureus | trimethoprim | Reference Gene CatalogResFinder Database | Confirmed |
| F99I | - | Target modification, dihydrofolate reductase DfrB | Staphylococcus aureus | trimethoprim | Reference Gene CatalogResFinder Database | Confirmed |
| H150R | - | Target modification, dihydrofolate reductase DfrB | Staphylococcus aureus | trimethoprim | Reference Gene CatalogResFinder Database | Confirmed |
| L25I | - | dihydrofolate reductase DfrB | Staphylococcus aureus | trimethoprim | Reference Gene Catalog | Established |
| Allele | Database | Papers | Drug Classes | Organisms | Countries | Years | Sequence Accession | Protein Accession |
|---|---|---|---|---|---|---|---|---|
| DfrB9 | Card DatabaseReference Gene CatalogReslit | 4 | Trimethoprim, Diaminopyrimidine antibiotic | Enterobacter cloacae, Vibrio cholerae, Escherichia coli | - | 2024 | KC675185.1 | AGM20434.1 |
| DfrB6 | Card DatabaseReference Gene CatalogResFinder DatabaseReslit | 8 | Trimethoprim, Diaminopyrimidine antibiotic | Salmonella enterica serovar Infantis, Escherichia coli DH5α, Salmonella enterica subsp. enterica serovar Infantis, Salmonella, uncultured bacterium | Global, Australia | 1995, 2006, 2013, 2023 | DQ274503 | ABB72057.1 |
| dfrB | Reslit | 14 | Trimethoprim | Staphylococcus aureus, Escherichia, Klebsiella, Shigella, Escherichia coli, Enterobacteriaceae, Pseudomonodaceae, Bacillaceae, Sphingomonadaceae, Comamonadaceae +3 more | United States, Global, India, South Africa, Europe, Kenya, USA, Portugal, Germany, Australia +5 more | 2009, 2016, 2019, 2020, 2021, 2022, 2023, 2025 | NC_002973|NC_002974|NC_002975 | - |
| DfrB8 | Reference Gene CatalogResFinder DatabaseReslit | 3 | Trimethoprim | Aeromonas hydrophila, Aeromonas | Global | 2011, 2023 | GU295656.1 | ADB54781.1 |
| DfrB3 | Card DatabaseReference Gene CatalogResFinder DatabaseReslit | 10 | Trimethoprim, Diaminopyrimidine antibiotic | Klebsiella aerogenes, Klebsiella oxytoca, Klebsiella pneumoniae, Escherichia coli, Aeromonas sp., Raoultella sp., Enterobacter hormaechei complex, Aeromonas sobria | Europe, Portugal, Poland, United Kingdom, Italy | 1994, 2012, 2016, 2020, 2023, 2025 | X72585.1 | CAA51181.1 |
| DfrB10 | Card DatabaseReference Gene CatalogReslit | 5 | Trimethoprim, Diaminopyrimidine antibiotic | Escherichia coli, Pseudomonas putida, Variovorax sp., Polaromonas sp., Rhodoferax sp., Ramlibacter sp. | Asia, Europe, America, Africa, North America, New Zealand, Greenland, Arctic, Antarctic | 2021, 2024 | NZ_CP010378.1|NZ_SWEG01000001.1|NZ_UWXD01000002.1|NZ_CP032569.1|NZ_KU130294.1|CP031876.1|NZ_CM002277.1|AOBK03000081.1 | ALZ46148.1 |
| DfrB11 | Card DatabaseReference Gene CatalogReslit | 4 | Trimethoprim, Diaminopyrimidine antibiotic | Escherichia coli, Betaproteobacteria bacterium HGW-Betaproteobacteria-16 | Asia, Europe, America, Africa | 2021 | NZ_CP010378.1|NZ_SWEG01000001.1|NZ_UWXD01000002.1|NZ_CP032569.1|NZ_KU130294.1|CP031876.1|NZ_CM002277.1|AOBK03000081.1 | PKO69073.1 |
| DfrB-H2 | Reslit | 1 | Trimethoprim | Escherichia coli | - | 2023 | - | - |
| DfrB-H5 | Reslit | 2 | Trimethoprim | Escherichia coli | - | 2023 | - | - |
New integron-associated gene cassette encoding a trimethoprim-resistant DfrB-type dihydrofolate reductase.
Research Article
A new integron-associated gene cassette, dfrB6, was identified in multidrug-resistant Salmonella enterica serovar Infantis strains, which confers resistance to trimethoprim.
New integron-associated gene cassette encoding a trimethoprim-resistant DfrB-type dihydrofolate reductase.
Research Article
Antistaphylococcal activity of dihydrophthalazine antifolates, a family of novel antibacterial drugs.
Research Article
The study identifies dihydrophthalazine antifolates as effective against staphylococcal infections, including methicillin- and vancomycin-resistant strains. It characterizes mutations in dihydrofolate reductase genes (dfr(A), dfr(B), and dfr(C)) that confer resistance to trimethoprim.
Class 1 and class 2 integrons in multidrug-resistant gram-negative bacteria isolated from the Salmon River, British Columbia.
Research Article
Antimicrobial Resistance in Bacteria: Mechanisms and Current Challenges
Research Article
This paper characterizes several beta-lactamases, including TEM-1, SHV-1, CTX-M-15, and NDM-1, which confer resistance to various beta-lactam antibiotics. It also identifies erm(B) and mef(A) as mechanisms of macrolide, lincosamide, and streptogramin B resistance. Additionally, aadA1 and aac(6')-Ib are noted for aminoglycoside resistance, while catA1 and floR contribute to chloramphenicol resistance. The vanA gene is associated with glycopeptide resistance, and mcr-1 is linked to polymyxin resistance.
Antimicrobial Resistance in Bacteria: Mechanisms and Current Challenges
Research Article
This paper characterizes several beta-lactamases, including TEM-1, SHV-1, CTX-M-15, and NDM-1, which confer resistance to various beta-lactam antibiotics. It also identifies erm(B) and mef(A) as mechanisms of macrolide, lincosamide, and streptogramin B resistance. Additionally, aadA1 and aac(6')-Ib are noted for aminoglycoside resistance, while catA1 and floR contribute to chloramphenicol resistance. The vanA gene is associated with glycopeptide resistance, and mcr-1 is linked to polymyxin resistance.
Antimicrobial Resistance in Bacteria: Mechanisms and Current Challenges
Research Article
This paper characterizes several beta-lactamases, including TEM-1, SHV-1, CTX-M-15, and NDM-1, which confer resistance to various beta-lactam antibiotics. It also identifies erm(B) and mef(A) as mechanisms of macrolide, lincosamide, and streptogramin B resistance. Additionally, aadA1 and aac(6')-Ib are noted for aminoglycoside resistance, while catA1 and floR contribute to chloramphenicol resistance. The vanA gene is associated with glycopeptide resistance, and mcr-1 is linked to polymyxin resistance.
Multiresistant Enterobacteriaceae with class 1 and class 2 integrons in a municipal wastewater treatment plant.
Research Article
Multiresistant Enterobacteriaceae with class 1 and class 2 integrons in a municipal wastewater treatment plant.
Research Article
Into the wild: dissemination of antibiotic resistance determinants via a species recovery program.
Research Article
Class 1 integrons containing gene cassettes encoding resistance to streptomycin, spectinomycin, and trimethoprim were detected in captive brush-tailed rock wallabies, suggesting acquisition from human or domestic animal sources.
Architecture of Class 1, 2, and 3 Integrons from Gram Negative Bacteria Recovered among Fruits and Vegetables.
Research Article
The study identified several AMR genes in Gram-negative bacteria from fresh produce, including mcr-1, qnrA1, blaGES-11, mphA, and oqxAB, highlighting the presence of mobile genetic elements and clinically relevant resistance genes.
MRSA Isolates from United States Hospitals Carry dfrG and dfrK Resistance Genes and Succumb to Propargyl-Linked Antifolates.
Research Article
The study identifies dfrG and dfrK as novel plasmid-encoded trimethoprim resistance genes in MRSA and MSSA isolates from the United States, demonstrating their role in conferring high-level resistance to trimethoprim.
Antibiotic Resistance and the MRSA Problem.
Review
The paper discusses the mechanisms of antibiotic resistance in Staphylococcus aureus, focusing on beta-lactam resistance through the blaZ and mecA genes, glycopeptide resistance via the vanA operon, and resistance to other antibiotics through various genes and mutations.
Antibiotic Susceptibility, Virulence Pattern, and Typing of Staphylococcus aureus Strains Isolated From Variety of Infections in India.
Research Article
The study identified various AMR genes in S. aureus isolates, including mecA, pvl, czrC, qacA/B, aac(6')/aph(2), aph(3'-III), msrA, ermA, ermC, mphC, tetK, tetL, tetM, cat::pC221, cat::pC223, cat::pC194, dfrA, dfrB, and dfrG, which confer resistance to multiple antibiotics such as oxacillin, chloramphenicol, gentamicin, erythromycin, clindamycin, tetracycline, and trimethoprim.
Frame-shifted proteins of a given gene retain the same function.
Research Article
The study shows that frame-shifted versions of the dfrB3 gene, which encodes a dihydrofolate reductase, retain the ability to confer resistance to trimethoprim (TMP) in E. coli. Both +1 and -1 frame-shifted proteins of dfrB3 were found to catalyze the reduction of dihydrofolate to tetrahydrofolate, similar to the wild-type enzyme.
Molecular Characterization and Comparative Genomics of IncQ-3 Plasmids Conferring Resistance to Various Antibiotics Isolated from a Wastewater Treatment Plant in Warsaw (Poland).
Research Article
The study identified several AMR genes in IncQ-3 plasmids, including blaGES-7, qnrS2, aac(6')-ib, dfrB3, and blaFOX-15, which confer resistance to beta-lactams, fluoroquinolones, aminoglycosides, and trimethoprim.
Occurrence of Antibiotic-Resistant Bacteria and Genes in Two Drinking Water Treatment and Distribution Systems in the North-West Province of South Africa.
Research Article
The study identified several antibiotic resistance genes, including strA, strB, aadA, dfrB, bla CTX-M, and tetA, in heterotrophic bacteria from drinking water treatment and distribution systems in South Africa.
The Bacterial Genomic Context of Highly Trimethoprim-Resistant DfrB Dihydrofolate Reductases Highlights an Emerging Threat to Public Health.
Research Article
The study identifies and characterizes two novel trimethoprim-resistant DfrB dihydrofolate reductases, dfrb10 and dfrb11, highlighting their potential as emerging threats to public health.
The Bacterial Genomic Context of Highly Trimethoprim-Resistant DfrB Dihydrofolate Reductases Highlights an Emerging Threat to Public Health.
Research Article
The study identifies and characterizes two novel trimethoprim-resistant DfrB dihydrofolate reductases, dfrb10 and dfrb11, highlighting their potential as emerging threats to public health.
The Bacterial Genomic Context of Highly Trimethoprim-Resistant DfrB Dihydrofolate Reductases Highlights an Emerging Threat to Public Health.
Research Article
The Bacterial Genomic Context of Highly Trimethoprim-Resistant DfrB Dihydrofolate Reductases Highlights an Emerging Threat to Public Health.
Research Article
The Bacterial Genomic Context of Highly Trimethoprim-Resistant DfrB Dihydrofolate Reductases Highlights an Emerging Threat to Public Health.
Research Article
The Bacterial Genomic Context of Highly Trimethoprim-Resistant DfrB Dihydrofolate Reductases Highlights an Emerging Threat to Public Health.
Research Article
Antimicrobial Susceptibility and Detection of Virulence-Associated Genes in Escherichia coli Strains Isolated from Commercial Broilers.
Research Article
The study identified several AMR genes in E. coli strains from commercial broilers, including bla CTX-M-1 and bla CTX-M-2 for cephalosporin resistance, qnrA, qnrB, qnrS for fluoroquinolone resistance, aac(6')-Ib-cr for fluoroquinolone and aminoglycoside resistance, tetA and tetB for tetracycline resistance, sul1 and sul2 for sulfonamide resistance, aadA for aminoglycoside resistance, dfrA and dfrB for trimethoprim resistance, and mcr1 and mcr2 for polymyxin resistance.
Genetic Diversity, Distribution, and Genomic Characterization of Antibiotic Resistance and Virulence of Clinical Pseudomonas aeruginosa Strains in Kenya.
Research Article
The study identified multiple AMR genes and mutations in P. aeruginosa isolates from Kenya, including carbapenemases (blaNDM-1, blaVIM-6), fluoroquinolone resistance genes (qnrVC1, crpP), aminoglycoside resistance genes (aac(3)-IId, aph(3')-Ib, ant(3'')-Ia), tetracycline resistance genes (tetA, tetG), phenicol resistance genes (floR, cmlA), sulfonamide resistance gene (sul), trimethoprim resistance gene (dfrB), glycopeptide resistance gene (ble), and macrolide resistance gene (EreA). Additionally, mutations in gyrA and parC were associated with fluoroquinolone resistance.
Occurrence of antibiotics and bacterial resistance genes in wastewater: resistance mechanisms and antimicrobial resistance control approaches.
Review
The study identifies several AMR genes and mutations associated with resistance to various antibiotics in wastewater environments, highlighting the role of these genes in the spread of antimicrobial resistance.
Microbiological and Molecular Features Associated with Persistent and Relapsing Staphylococcus aureus Prosthetic Joint Infection.
Research Article
The study identified several AMR genes and mutations in Staphylococcus aureus isolates from persistent and relapsing prosthetic joint infections, including aac(6')-aph(2"), dfrB, blaZ, grlA, gyrA, and norA. These genes and mutations were experimentally validated and associated with resistance to various antibiotics.
A conserved SH3-like fold in diverse putative proteins tetramerizes into an oxidoreductase providing an antimicrobial resistance phenotype.
Research Article
The study identifies and characterizes DfrB homologues that display dihydrofolate reductase activity and confer trimethoprim resistance, highlighting the role of the SH3-like fold in providing antimicrobial resistance.
A conserved SH3-like fold in diverse putative proteins tetramerizes into an oxidoreductase providing an antimicrobial resistance phenotype.
Research Article
The study identifies and characterizes DfrB homologues that display dihydrofolate reductase activity and confer trimethoprim resistance, highlighting the role of the SH3-like fold in providing antimicrobial resistance.
A conserved SH3-like fold in diverse putative proteins tetramerizes into an oxidoreductase providing an antimicrobial resistance phenotype.
Research Article
The study identifies and characterizes DfrB homologues that display dihydrofolate reductase activity and confer trimethoprim resistance, highlighting the role of the SH3-like fold in providing antimicrobial resistance.
An ST131 clade and a phylogroup A clade bearing an O101-like O-antigen cluster predominate among bloodstream Escherichia coli isolates from South-West Nigeria hospitals.
Research Article
The study identified several AMR genes and mutations in bloodstream E. coli isolates from South-West Nigeria, including bla CTX-M-15, dfrA, dfrB, and various quinolone resistance genes. Mutations in gyrA, parC, and parE were also associated with fluoroquinolone resistance.
Identification of diverse antibiotic resistant bacteria in agricultural soil with H(2)(18)O stable isotope probing combined with high-throughput sequencing.
Research Article
The study identified several antimicrobial resistance genes (ARGs) in agricultural soil using H2 18O stable isotope probing combined with high-throughput sequencing. These included aph(3')-IIc, oqxB, blaTEM-181, blaL1, and dfrB3, which conferred resistance to various antibiotics such as aminoglycosides, chloramphenicol, quinolones, trimethoprim, and beta-lactams.
Antimicrobial resistance heterogeneity among multidrug-resistant Gram-negative pathogens: Phenotypic, genotypic, and proteomic analysis.
Research Article
The study identified various AMR genes in multidrug-resistant Gram-negative pathogens, highlighting the prevalence of bla CTX-M-15, bla CMY-42, bla NDM-5, aadA, bla TEM-1B, bla OXA-232, bla NDM-1, rmtB, rmtC, bla VEB, bla VIM-2, aph(3'), strA/B, bla OXA-23, aph (3′), catB, dfrB, bla VIM-2, fosA, oqxA, oqxB, bla OXA-23, bla CARB, bla OXA-91, bla OXA-51, bla PAO, bla SHV, aph (3′)-Ib, aph (6)-Id, mphE, msrE, ermB, mphA, aadA, rmtB, qnrB, dfrA, sul1, sul2, and fosA7.
Identification of promoter activity in gene-less cassettes from Vibrionaceae superintegrons.
Research Article
The study identifies promoter activity in gene-less cassettes from Vibrionaceae superintegrons, demonstrating that these cassettes can enhance the expression of downstream genes, including the trimethoprim resistance gene dfrB9, significantly increasing resistance in V. cholerae and E. coli.
Bacteria of the order Burkholderiales are original environmental hosts of type II trimethoprim resistance genes (dfrB).
Research Article
The study identifies bacteria of the order Burkholderiales, particularly the family Comamonadaceae, as the original environmental hosts of dfrB genes, which confer resistance to trimethoprim. These genes are prevalent in both freshwater and soil microbiomes.
Pan-genome analysis of the Enterobacter hormaechei complex highlights its genomic flexibility and pertinence as a multidrug resistant pathogen.
Research Article
The study identifies a wide range of antibiotic resistance genes in the Enterobacter hormaechei complex, highlighting its multidrug-resistant nature and the role of mobile genetic elements in the dissemination of resistance.
From Binding to Catalysis: Emergence of a Rudimentary Enzyme Conferring Intrinsic Antibiotic Resistance.
Research Article
The study identifies DfrB as a rudimentary enzyme that confers intrinsic resistance to trimethoprim through homotetramerization, which is necessary and sufficient for catalytic activity.
From Binding to Catalysis: Emergence of a Rudimentary Enzyme Conferring Intrinsic Antibiotic Resistance.
Research Article
The study identifies DfrB as a rudimentary enzyme that confers intrinsic resistance to trimethoprim through homotetramerization, which is necessary and sufficient for catalytic activity.
Antibiotic-resistance and virulence-related genes in commercially bottled natural mineral waters.
Research Article
The study identified several antibiotic resistance genes (ARGs) in commercially bottled natural mineral waters, including TEM-116, ceoB, mtrA, AAC(6')-31, APH(3'')-Ib, APH(6)-Id, dfrB3, and RbpA. These genes were found to confer resistance to various antibiotics such as beta-lactams, aminoglycosides, trimethoprim, and rifampin.
Expression of antibiotic resistance genes in the integrated cassettes of integrons.
Research Article
Expression of antibiotic resistance genes in the integrated cassettes of integrons.
Research Article
Expression of antibiotic resistance genes in the integrated cassettes of integrons.
Research Article
Transposon Tn5090 of plasmid R751, which carries an integron, is related to Tn7, Mu, and the retroelements.
Research Article
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