Mechanisms involved in the development of resistance to fluoroquinolones in Escherichia coli isolates

María Del Mar Tavío, Jordi Vila, Joaquím Ruiz, José Ruiz, Antonio Manuel Martín-Sánchez, María Teresa Jiménez De Anta

Resultado de la investigación: Contribución a una revistaArtículorevisión exhaustiva

88 Citas (Scopus)

Resumen

Eighteen quinolone-resistant isolates of Escherichia coli were selected by exposing ten clinical isolates to increasing concentrations of norfloxacin and lomefloxacin. The mutant isolates showed a multiple-antibiotic-resistance phenotype. All of them contained single mutations in gyrA consisting of the substitution of Ser-83→Leu (n = 14), Val (n = 1) or Ala (n = 1) and the substitution of Asp-87→Asn (n = 2). Only one concomitant mutation in parC (Ser-80→Arg) was detected. Four parent isolates exhibited a single mutation in gyrA which required ≤ 1 mg/L of norfloxacin to be inhibited. Fluoroquinolone resistance, in the 18 quinolone-resistant mutants, was a result of mutations affecting DNA gyrase plus decreased fluoroquinolone uptake. This latter mechanism of resistance was a combined effect of an absence of OmpF and an increase in active efflux in eight isolates, or an increased active efflux alone in the remaining ten selected mutants.

Idioma originalInglés
Páginas (desde-hasta)735-742
Número de páginas8
PublicaciónJournal of Antimicrobial Chemotherapy
Volumen44
N.º6
DOI
EstadoPublicada - 1999

Huella

Profundice en los temas de investigación de 'Mechanisms involved in the development of resistance to fluoroquinolones in Escherichia coli isolates'. En conjunto forman una huella única.

Citar esto