Pv. Adrian et al., NEW TRIMETHOPRIM-RESISTANT DIHYDROFOLATE-REDUCTASE CASSETTE, DFRXV, INSERTED IN A CLASS-1 INTEGRON, Antimicrobial agents and chemotherapy, 42(9), 1998, pp. 2221-2224
The nucleotide sequence of a plasmid-borne trimethoprim resistance gen
e from a commensal fecal Escherichia coli isolate revealed a new dihyd
rofolate reductase gene, dfrXV, which occurred as a gene cassette inte
grated in a site-specific manner in a class 1 integron. The new gene s
hows 84% nucleotide identity and the predicted protein shows 90% amino
acid identity with dfrI and DHFR type I, respectively. Genes for spec
tinomycin resistance, aadA1 [ant (3 '')-Ia], and sulfonamide resistanc
e, sul1, were located downstream of dfrXV in a manner identical to tha
t in pLMO229.