Please use this identifier to cite or link to this item:
Title: Urinary Tract Physiological Conditions Promote Ciprofloxacin Resistance in Low-Level-Quinolone-Resistant Escherichia coli.
Authors: Martín-Gutiérrez, Guillermo
Rodríguez-Beltrán, Jerónimo
Rodríguez-Martínez, José Manuel
Costas, Coloma
Aznar, Javier
Pascual, Álvaro
Blázquez, Jesús
metadata.dc.subject.mesh: Anti-Bacterial Agents
Drug Resistance, Bacterial
Escherichia coli
Escherichia coli Infections
Healthy Volunteers
Hydrogen-Ion Concentration
Microbial Sensitivity Tests
Prospective Studies
Urinary Tract Infections
Issue Date: 20-Jun-2016
Abstract: 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.
metadata.dc.identifier.doi: 10.1128/AAC.00602-16
Appears in Collections:Producción 2020

Files in This Item:
There are no files associated with this item.

This item is protected by original copyright

Except where otherwise noted, Items on the Andalusian Health Repository site are licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives License.