title: High-level resistance to trimethoprim in Shigella sonnei associated with plasmid-encoded dihydrofolate reductase type I.
abstract: By DNA hybridization, the gene encoding dihydrofolate reductase type I was found in 58 of 59 highly trimethoprim-resistant clinical isolates of Shigella sonnei obtained from 1981 through 1987 in Madrid, Spain. No strain harbored the type II gene. In selected strains, the type I gene was demonstrated to be in a plasmid.
authors.affiliation: Servicio de Microbiología, Hospital Primero de Octubre, Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Delgado
authors.forename: J R
authors.initials: JR
authors.lastname: Otero
mesh_terms: D009693:Nucleic Acid Hybridization; D011815:R Factors; D012764:Shigella sonnei / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*; D014296:Trimethoprim Resistance / Q000235:genetics*
chemical_list: D013762:Tetrahydrofolate Dehydrogenase