Artículo
Urinary tract physiological conditions promote ciprofloxacin resistance in low-level-quinolone-resistant Escherichia coli
Autor/es | Martín Gutiérrez, Guillermo
Rodríguez Beltrán, Jerónimo Rodríguez Martínez, José Manuel Costas, Coloma Aznar Martín, Javier Pascual Hernández, Álvaro Blázquez, Jesús |
Fecha de publicación | 2016-07-01 |
Fecha de depósito | 2017-09-28 |
Publicado en |
|
Resumen | Escherichia coli isolates carrying chromosomally encoded low-level-quinolone-resistant (LLQR) determinants are frequently found in urinary tract infections (UTIs). LLQR mutations are considered the first step in the ... Escherichia coli isolates carrying chromosomally encoded low-level-quinolone-resistant (LLQR) determinants are frequently found in urinary tract infections (UTIs). LLQR mutations are considered the first step in the evolutionary pathway producing high-level fluoroquinolone resistance. Therefore, their evolution and dissemination might influence the outcome of fluoroquinolone treatments of UTI. Previous studies support the notion that low urine pH decreases susceptibility to ciprofloxacin (CIP) in E. coli. However, the effect of the urinary tract physiological parameters on the activity of ciprofloxacin against LLQR E. coli strains has received little attention. We have studied the activity of ciprofloxacin under physiological urinary tract conditions against a set of well-characterized isogenic E. coli derivatives carrying the most prevalent chromosomal mutations (ΔmarR, gyrA-S83L, gyrA-D87N, and parC-S80R and some combinations). The results presented here demonstrate that all the LLQR strains studied became resistant to ciprofloxacin (according to CLSI guidelines) under physiological conditions whereas the control strain lacking LLQR mutations did not. Moreover, the survival of some LLQR E. coli variants increased up to 100-fold after challenge with a high concentration of ciprofloxacin under UTI conditions compared to the results seen with Mueller-Hinton broth. These selective conditions could explain the high prevalence of LLQR mutations in E. coli. Furthermore, our data strongly suggest that recommended methods for MIC determination produce poor estimations of CIP activity against LLQR E. coli in UTIs. |
Agencias financiadoras | Instituto de Salud Carlos III |
Identificador del proyecto | PI13/00063 |
Cita | Martín Gutiérrez, G., Rodríguez Beltrán, J., Rodríguez Martínez, J.M., Costas, C., Aznar Martín, J., Pascual Hernández, Á. y Blázquez, J. (2016). Urinary tract physiological conditions promote ciprofloxacin resistance in low-level-quinolone-resistant Escherichia coli. Antimicrobial Agents and Chemotherapy, 60 (7), 4252-4258. |
Ficheros | Tamaño | Formato | Ver | Descripción |
---|---|---|---|---|
Urinary Tract Physiological ... | 639.3Kb | [PDF] | Ver/ | |