Browse AMR Genes
Explore antimicrobial resistance genes from the literature
Explore antimicrobial resistance genes from the literature
Dihydrofolate reductase
Overview
| Allele | Database | Papers | Drug Classes | Organisms | Countries | Years | Sequence Accession | Protein Accession |
|---|---|---|---|---|---|---|---|---|
| DfrA8 | Card DatabaseReference Gene CatalogResFinder DatabaseReslit | 27 | Trimethoprim, Trimethoprim/sulfamethoxazole +1 |
| Peru|Bolivia, Bolivia, Sweden, Global, Kenya, South Asia|sub-Saharan Africa|The Gambia|Mali|Kenya|Mozambique|Bangladesh|India|Pakistan, Ecuador, United Kingdom, Brazil, Europe|Netherlands, Denmark|Finland|Iceland|Lithuania|Netherlands|Spain, Finland|Malaysia|Poland|Lithuania|United States|Canada|China|Japan|Norway|Brazil|Netherlands|Hong Kong|Germany|Switzerland|Portugal|Australia|UK|Vietnam|Spain|Dominican Republic|India|Thailand, sub-Saharan Africa|Burkina Faso|Ghana|Guinea-Bissau|Kenya|Senegal, The Gambia, North America|Asia|Europe|Middle East|Africa, Abuja, Nigeria, Ontario, Canada, United Kingdom|High-risk countries, Uruguay|Chile, Somali region, Ethiopia|Somali Region, Ethiopia, Costa Rica |
| 1995, 2006, 2007, 2010, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 |
| AAA68493.1 |
| dfr A8 | Reslit | 1 | Trimethoprim | Escherichia coli | Southeast Nigeria | 2022 | PRJEB43719 | - |
| dfrA8 | Card DatabaseResFinder Database | 2 | TRIMETHOPRIM | Escherichia coli +1 | - | 1995 | U10186 | AHV80711.1 |
Multidrug-resistant commensal Escherichia coli in children, Peru and Bolivia.
The study identified multiple multidrug-resistant commensal E. coli isolates in children from Peru and Bolivia, highlighting the prevalence of resistance genes such as blaTEM, tet(A), tet(B), dfrA8, sul1, sul2, and catI.
Population structure and resistance genes in antibiotic-resistant bacteria from a remote community with minimal antibiotic exposure.
The study identified various acquired antibiotic resistance genes in commensal E. coli isolates from a remote community with minimal antibiotic exposure, including blaTEM, catI, cmlA6, tet(A), tet(B), dfrA1, dfrA7, dfrA8, dfrA17, sul1, sul2, aphA1, aadA1, aadA2, aadA5, aadB, and sat-1. These genes were found to be similar to those seen in antibiotic-exposed settings, indicating the dissemination of resistant bacteria and resistance genes from such environments.
Molecular characterisation of trimethoprim resistance in Escherichia coli and Klebsiella pneumoniae during a two year intervention on trimethoprim use.
The study identified various dfr genes, including dfrA1, dfrA17, dfrA5, dfrA7, dfrA8, dfrA12, dfrA14, dfrA24, and dfrA26, as major contributors to trimethoprim resistance in E. coli and K. pneumoniae. The distribution of these genes remained largely unchanged during the intervention period.
Antimicrobial Resistance in Bacteria: Mechanisms and Current Challenges
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 of Klebsiella pneumoniae stool isolates circulating in Kenya.
The study identified 46 AMR genes or gene families in 90 Klebsiella pneumoniae isolates from Kenya, highlighting the prevalence of multidrug resistance and the diversity of resistance mechanisms.
Dynamics of antimicrobial resistance in intestinal Escherichia coli from children in community settings in South Asia and sub-Saharan Africa.
The study identified multiple AMR genes in aEPEC isolates from children in South Asia and sub-Saharan Africa, highlighting the prevalence of resistance to multiple antibiotics, including ampicillin, streptomycin, trimethoprim/sulphamethoxazole, and tetracycline.
Diverse Commensal Escherichia coli Clones and Plasmids Disseminate Antimicrobial Resistance Genes in Domestic Animals and Children in a Semirural Community in Ecuador.
The study identified various antimicrobial resistance (AMR) genes in commensal Escherichia coli isolates from children and domestic animals in a semirural community in Ecuador. These genes included blaTEM-1B, dfrA8, qnrB19, strA, strB, tetA, tetB, sul1, sul2, and others, contributing to resistance against multiple antibiotics such as ampicillin, trimethoprim, tetracycline, and sulfamethoxazole. The research highlights the role of plasmids in disseminating these AMR genes and emphasizes the complexity of AMR transmission in such environments.
Use of whole genome sequencing of commensal Escherichia coli in pigs for antimicrobial resistance surveillance, United Kingdom, 2018.
The study analyzed 515 E. coli isolates from pigs using whole genome sequencing to identify AMR genes and mutations. Key findings include the prevalence of blaTEM-1b, tet(A), and tetA(B) genes, along with various mutations in gyrA, parC, and parE that confer resistance to fluoroquinolones. The study highlights the effectiveness of WGS in predicting AMR phenotypes with high concordance to MIC results.
Comparative analysis of multidrug resistance plasmids and genetic background of CTX-M-producing Escherichia coli recovered from captive wild animals.
The study identifies multiple AMR genes and mutations in MDR E. coli strains from captive wild animals, highlighting the presence of CTX-M-8 and CTX-M-65 beta-lactamases, along with various other resistance mechanisms such as aminoglycoside, tetracycline, and fluoroquinolone resistance genes, as well as mutations in quinolone resistance-determining regions.
Genomic characterization of multidrug-resistant ESBL-producing Escherichia coli ST58 causing fatal colibacillosis in critically endangered Brazilian merganser (Mergus octosetaceus).
The study identifies a multidrug-resistant ESBL-producing E. coli ST58 strain (PMPU) isolated from a critically endangered Brazilian merganser, carrying genes conferring resistance to various antibiotics, heavy metals, and disinfectants, along with fluoroquinolone resistance mutations.
A Multifactorial Approach for Surveillance of Shigella spp. and Entero-Invasive Escherichia coli Is Important for Detecting (Inter)national Clusters.
The study identified several AMR genes and mutations in Shigella spp. and EIEC isolates, including beta-lactamases (blaTEM-1b, blaOXA-1, blaCTX-M-15, blaCTX-M-32, blaCTX-M-55, blaDHA-1), dihydrofolate reductase variants (dfrA1, dfrA14, dfrA17, dfrA7, dfrA8), sulfonamide resistance genes (sul1, sul2), macrolide resistance genes (erm(B), mphA), and chromosomal mutations in gyrA, parC, and parE associated with ciprofloxacin resistance.
Employing MIC Data for Mink Pathogens to Propose Tentative Epidemiological Cut-Off Values: A Step Toward Rationalizing Antimicrobial Use in Mink.
The study identified several AMR genes in mink pathogens, including beta-lactamases (blaTEM-1, blaCTX-M-1), tetracycline resistance genes (tet(A), tet(B)), aminoglycoside resistance genes (aadA5, aadA1), sulfonamide resistance genes (sul2), dihydrofolate reductase genes (dfrA1, dfrA5, dfrA8, dfrA14), macrolide/lincosamide/streptogramin B resistance genes (erm), lincomycin resistance gene (lnu(A)), spectinomycin resistance gene (spc), and additional sulfonamide and trimethoprim resistance genes (sul1, sul3, dfrK, dfrG).
Plasmid-Borne and Chromosomal ESBL/AmpC Genes in Escherichia coli and Klebsiella pneumoniae in Global Food Products.
The study identified several beta-lactamase genes, including bla CTX-M-1, bla CTX-M-15, bla CTX-M-55, bla CTX-M-65, bla SHV-12, bla SHV-28, bla SHV-81, bla TEM-1B, bla TEM-52C, bla CARB-2, bla OXA-1, bla DHA-1, and bla CMY-2, along with other AMR genes such as aac(3)-IIa, aac(6')-Ib-cr, aph(3')-Ia, aph(3')-Ib, aph(6)-Id, aadA1, aadA2, aph(4)-Ia, oqxA, oqxB, qnrB1, qnrS1, floR, sul2, sul1, tet(A), dfrA14, dfrA1, dfrA17, dfrA8, dfrA12, dfrA16, dfrA15, catB3, cmlA1, arr-2, and qnrB19, which confer resistance to various antibiotics in Escherichia coli and Klebsiella pneumoniae isolated from food products.
The genomic epidemiology of multi-drug resistant invasive non-typhoidal Salmonella in selected sub-Saharan African countries.
The study identified multiple AMR genes and mutations in invasive non-typhoidal Salmonella isolates from sub-Saharan Africa, highlighting the prevalence of multidrug resistance.
Genomic diversity and antimicrobial resistance among non-typhoidal Salmonella associated with human disease in The Gambia.
The study identified various antimicrobial resistance (AMR) genes in non-typhoidal Salmonella isolates from The Gambia, including aac(6')-Iaa_1, aph_3_Ib, aph_6_Id, dfrA14, dfrA7, dfrA8, blaTEM-1B, catA1_1, fosA7_1, mph_A, sul1, sul2, tet_A, and tet_B. These genes confer resistance to aminoglycosides, trimethoprim, beta-lactams, chloramphenicol, fosfomycin, macrolides, sulfonamides, and tetracyclines. The study also found that multidrug resistance (MDR) was primarily associated with Salmonella serovar Enteritidis, especially in the eastern region.
Escherichia coli ST1193: Following in the Footsteps of E. coli ST131
The paper characterizes Escherichia coli ST1193 as an emerging multidrug-resistant clone with various AMR determinants, including beta-lactamases (bla CTX-M-15, bla CTX-M-14, bla CTX-M-27, bla CTX-M-55, bla OXA-1, bla TEM-1, bla CMY-42, bla CMY-2), aminoglycoside-modifying enzymes (aac(3)-IIa, aac(3)-IId, aac(6′)-Ib-cr, aadA1, aadA2, aadA5, aph(3′′)-Ib, aph(6)-Id), and other resistance genes (mcr-1, mph(A), erm(B), dfrA8, dfrA12, dfrA17, sul1, sul2, tetA, tetB).
Molecular characterization of extended spectrum cephalosporin resistant Escherichia coli isolated from livestock and in-contact humans in Southeast Nigeria.
The study identified four variants of bla CTX-M (CTX-M-15, CTX-M-55, CTX-M-64, and CTX-M-65) in extended-spectrum cephalosporin-resistant Escherichia coli from livestock and in-contact humans in Southeast Nigeria. Other AMR genes such as bla TEM-1b, aac 3-IId, qnr S1, and sul 2 were also characterized.
Molecular characterization of multi drug resistant Escherichia coli isolates at a tertiary hospital in Abuja, Nigeria.
The study identified several AMR genes in multi-drug resistant E. coli isolates, including bla CTX-M-15, bla CTX-M-14, bla CTX-M-27, bla CTX-M-65, bla OXA-1, bla OXA-2, bla CMY-2, bla NDM-1, bla NDM-5, aac(3)-IId, aac(3)-IIe, aac(6')-Ib-cr, aad A5, ant(2′′)-Ia, aph(3′′)-Ib, aph(3′′)-VI, aph(6)-Id, ermB, ermD, fosA3, fosA7, mdtM, emrD, sul1, sul2, sul3, tetA, tetB, tetM, dfrA1, dfrA7, dfrA8, dfrA12, dfrA14, dfrA17, dfrA82, dfrB4, qepA, qepA1, qepA2, qepA4, qnrB19, qnrS1, qacE, catA1, catA2, catB3, cmlA1, mphA.
A Cross-Validated Feature Selection (CVFS) approach for extracting the most parsimonious feature sets and discovering potential antimicrobial resistance (AMR) biomarkers.
The study presents a Cross-Validated Feature Selection (CVFS) approach for identifying the most parsimonious gene sets for predicting antimicrobial resistance (AMR) from bacterial pan-genomes. The CVFS approach was able to extract both known and novel AMR genes, demonstrating its effectiveness in selecting relevant features for AMR prediction.
Combining analytical epidemiology and genomic surveillance to identify risk factors associated with the spread of antimicrobial resistance in Salmonella enterica subsp. enterica serovar Heidelberg.
The study identified multiple AMR genes in Salmonella enterica subsp. enterica serovar Heidelberg, including bla CMY-2, bla TEM-1A, bla TEM-1B, bla TEM-214, mcr -9, and others, highlighting the prevalence of resistance to beta-lactams, aminoglycosides, and other antimicrobial agents.
Prevalence and Persistence of Antibiotic Resistance Determinants in the Gut of Travelers Returning to the United Kingdom is Associated with Colonization by Pathogenic Escherichia coli.
The study identified various antibiotic resistance genes in the gut microbiota of travelers returning to the UK, highlighting the association with colonization by pathogenic E. coli. Key findings include the prevalence of genes conferring resistance to macrolides, tetracyclines, sulfonamides, and others.
Genetics of resistance to trimethoprim in cotrimoxazole resistant uropathogenic Escherichia coli: integrons, transposons, and single gene cassettes.
The study identifies various dfrA gene cassettes, including dfrA1, dfrA5, dfrA7, dfrA8, and dfrA14, as the primary genetic determinants of trimethoprim resistance in cotrimoxazole-resistant uropathogenic E. coli strains. These genes are found in class 1 and 2 integrons, as well as in transposons.
Fecal carriage of ESBL-producing E. coli and genetic characterization in rural children and livestock in the Somali region, Ethiopia: a one health approach.
The study identified bla CTX-M-15 as the most prevalent ESBL gene in both human and animal E. coli isolates, along with other resistance genes such as bla TEM-1B, bla OXA-1, and various aminoglycoside, sulfonamide, and trimethoprim resistance genes. Mutations in gyrA, parC, and parE were also associated with fluoroquinolone resistance.
Human-wildlife ecological interactions shape Escherichia coli population and resistome in two sloth species from Costa Rica.
The study identified several AMR genes in E. coli isolates from two sloth species in Costa Rica, including blaTEM-1B, aph(3')-Id, aph(6)-Id, tet(A), tet(B), sul2, qnrS1, floR, and dfrA8, which were associated with resistance to various antibiotics.
Azithromycin resistance in nontyphoidal Salmonella in an urban informal settlement in Nairobi, Kenya.
The study identified several AMR genes in nontyphoidal Salmonella isolates, including aac(6')-Iaa, aph(3")-Ib, aph(6)-Id, ant(3")-Ia, sul1, sul2, dfrA1, dfrA8, tetA, mph(A), bla CTX-M-3, bla TEM-135, bla TEM-1B, and bla TEM-1C. These genes conferred resistance to various antibiotics such as aminoglycosides, sulfonamides, tetracycline, macrolides, and beta-lactams.
A new dhfrVIII trimethoprim-resistance gene, flanked by IS26, whose product is remote from other dihydrofolate reductases in parsimony analysis.
A new dhfrVIII trimethoprim-resistance gene, flanked by IS26, whose product is remote from other dihydrofolate reductases in parsimony analysis.
A new dhfrVIII trimethoprim-resistance gene, flanked by IS26, whose product is remote from other dihydrofolate reductases in parsimony analysis.
A new dhfrVIII trimethoprim-resistance gene, flanked by IS26, whose product is remote from other dihydrofolate reductases in parsimony analysis.
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