Suppression of the SOS response modifies spatiotemporal evolution, post-antibiotic effect, bacterial fitness and biofilm formation in quinolone-resistant Escherichia coli.

Background: Suppression of the SOS response has been proposed as a therapeutic strategy for potentiating quinolones against susceptible, low-level quinolone-resistant (LLQR) and resistant Enterobacteriaceae.

Objectives: To monitor the functionality of the SOS response in the evolution towards clinical quinolone resistance and study its impact on the evolution of spatiotemporal resistance.

Methods: An isogenic collection of Escherichia coli (derived from the strain ATCC 25922) carrying combinations of chromosomally and plasmid-mediated quinolone resistance mechanisms (including susceptible, LLQR and resistant phenotypes) and exhibiting a spectrum of SOS activity was used.

Quinolone Resistance Reversion by Targeting the SOS Response.

Suppression of the SOS response has been postulated as a therapeutic strategy for potentiating antimicrobial agents. We aimed to evaluate the impact of its suppression on reversing resistance using a model of isogenic strains of representing multiple levels of quinolone resistance. mutants exhibiting a spectrum of SOS activity were constructed from isogenic strains carrying quinolone resistance mechanisms with susceptible and resistant phenotypes.

Molecular insights into fosfomycin resistance in Escherichia coli.

Objectives: Fosfomycin activity in Escherichia coli depends on several genes of unknown importance for fosfomycin resistance. The objective was to characterize the role of uhpT , glpT , cyaA and ptsI genes in fosfomycin resistance in E. coli.

Role of inoculum and mutant frequency on fosfomycin MIC discrepancies by agar dilution and broth microdilution methods in Enterobacteriaceae.

Objectives: Fosfomycin is re-evaluated as a treatment of multidrug-resistant Enterobacteriaceae infections. However, MIC differences have been described among the different susceptibility testing. The aim was to study the role of the different inoculum size used in agar dilution with respect to broth microdilution, according to CLSI, in the fosfomycin MIC discrepancies.

Flow cytometry of microencapsulated colonies for genetics analysis of filamentous fungi.

The analysis of filamentous fungi by flow cytometry has been impossible to date due to their filamentous nature and size. In this work, we have developed a method that combines single-spore microencapsulation and large-particle flow cytometry as a powerful alternative for the genetic analysis of filamentous fungi. Individual spores were embedded in monodisperse alginate microparticles and incubated in the appropriate conditions.