New trimethoprim-resistant dihydrofolate reductase cassette, dfrXV, inserted in a class 1 integron.
The nucleotide sequence of a plasmid-borne trimethoprim resistance gene from a commensal fecal Escherichia coli isolate revealed a new dihydrofolate reductase gene, dfrXV, which occurred as a gene cassette integrated in a site-specific manner in a class 1 integron. The new gene shows 84% nucleotide identity and the predicted protein shows 90% amino acid identity with dfrI and DHFR type I, respectively. Genes for spectinomycin resistance, aadA1 [ant (3")-Ia], and sulfonamide resistance, sulI, were located downstream of dfrXV in a manner identical to that in pLMO229.
Adrian
P V
PV
Department of Medical Microbiology, University of the Witwatersrand, and the South African Institute for Medical Research, Johannesburg, South Africa. petera@mail.saimr.wits.ac.za
DU Plessis
M
M
Klugman
K P
KP
Amyes
S G
SG
D000595:Amino Acid Sequence; D001483:Base Sequence; D003227:Conjugation, Genetic; D004926:Escherichia coli / Q000235:genetics*; D005493:Folic Acid Antagonists / Q000494:pharmacology; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*; D014296:Trimethoprim Resistance / Q000235:genetics*
D005493:Folic Acid Antagonists; D013762:Tetrahydrofolate Dehydrogenase