title: Antibiotic resistance and plasmid pattern of enterotoxigenic ST-a strains of Escherichia coli isolated in Puebla, México.
abstract: Antibiotic susceptibilities of 22 strains of Escherichia coli isolated from children from 0 to 3 years old at the University Hospital of Puebla were determined. Almost all strains were resistant to ampicillin, tetracycline, streptomycin, and kanamycin. Gel electrophoresis of DNA from 10 clinical strains of E. coli revealed a heterogeneous plasmid population. Plasmid DNA, ranging in molecular mass from 1.8 to 120 megadaltons, was demonstrated in 10 strains. Moreover, the frequency of antibiotic transfer ranged from 1.6/10(8) to 2/10, and the simultaneous transfer of the gene encoding heat-stable enterotoxin was also determined. Six out of 10 strains tested were able to cotransfer ST-a as demonstrated by the suckling mouse test. It is possible that antibiotic selective pressure may increase the isolation of enterotoxigenic E. coli strains.
authors.affiliation: Departamento de Investigaciones Microbiológicas, Universidad Autóma de Puebla, México.
authors.forename: L Y
authors.initials: LY
authors.lastname: Martínez
authors.forename: M M
authors.initials: MM
authors.lastname: Arenas
authors.forename: M Y
authors.initials: MY
authors.lastname: Montes
authors.forename: L J
authors.initials: LJ
authors.lastname: Martínez
authors.forename: B E
authors.initials: BE
authors.lastname: Baca
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics; D002675:Child, Preschool; D003227:Conjugation, Genetic; D004352:Drug Resistance, Microbial; D004768:Enterotoxins / Q000096:biosynthesis / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D010957:Plasmids; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C034151:heat stable toxin (E coli)