title: A novel sequence framework (bla(TEM-1G)) encoding the parental TEM-1 beta-lactamase.
abstract: A novel parental bla(TEM) gene (bla(TEM-1G)), encoding a TEM-1 beta-lactamase (pI of 5.4) produced by the uropathogenic Escherichia coli strain FMV194 was isolated from a dog. We report PCR-restriction fragment length polymorphism analysis and nucleotide sequencing of this gene. The bla(TEM-1G) sequence was identical to the bla(TEM-1C) gene framework in the coding and promoter (P3) regions, except for a silent G(604)-->T mutation in the coding region. Molecular phylogenetic analysis of parental bla(TEM) genes indicated two distinct groups, one comprising bla(TEM-1F) and bla(TEM-2). The other group comprises bla(TEM-1C) which is the probable ancestor of bla(TEM-1A), bla(TEM-1D) and bla(TEM-1G). The bla(TEM-1G) gene has the same framework as a gene encoding an inhibitor-resistant TEM beta-lactamase produced by an E. coli strain of human origin. Thus, parental bla(TEM) genes encoding beta-lactamases in E. coli strains isolated from different host species, in this case human and canine, may be phylogenetically very close.
authors.affiliation: CIISA, Faculty of Veterinary Medicine, Universidade Técnica de Lisboa, Rua Prof. Cid dos Santos, 1300-477 Lisboa, Portugal.
authors.forename: Constança
authors.initials: C
authors.lastname: Pomba-Féria
authors.forename: Manuela
authors.initials: M
authors.lastname: Caniça
mesh_terms: D000818:Animals; D001483:Base Sequence; D004285:Dogs; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D005798:Genes, Bacterial; D009154:Mutation; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic; D017385:Sequence Homology; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D001618:beta-Lactamases; C034413:beta-lactamase TEM-1