Evaluation of temocillin efficacy against KPC-2-producing Klebsiella pneumoniae isolates in a hollow-fibre infection model.

Background: Temocillin is an old antimicrobial that is resistant to hydrolysis by ESBLs but has variable activity against carbapenemase-producing Enterobacteriaceae. The current EUCAST susceptibility breakpoints for Enterobacterales are set at ≤16 mg/L (susceptible with increased exposure) based on a dose of 2 g q8h, but there is limited information on the efficacy of this dose against temocillin-susceptible carbapenemase-producing Klebsiella pneumoniae isolates.

Objectives: To evaluate the efficacy of this dose using a hollow-fibre infection model (HFIM) against six KPC-2-producing clinical isolates of K.

Effect of Glycerol on Fosfomycin Activity against .

Fosfomycin is an antimicrobial that inhibits the biosynthesis of peptidoglycan by entering the bacteria through two channels (UhpT and GlpT). Glycerol is clinically used as a treatment for elevated intracranial pressure and induces the expression of in Glycerol might offer synergistic activity by increasing fosfomycin uptake. The present study evaluates the use of glycerol at physiological concentrations in combination with fosfomycin against a collection of isogenic mutants of fosfomycin-related genes in strains.

Role of inorganic phosphate concentrations in in vitro activity of fosfomycin.

Objectives: The objective of this study was to evaluate the in vitro activity of fosfomycin under different physiological concentrations of inorganic phosphate (P).

Methods: The wild-type BW25113 strain, four isogenic mutants (ΔglpT, ΔuhpT, ΔglpT-uhpT, and ΔphoB) and six clinical isolates of Escherichia coli with different fosfomycin susceptibilities were used. EUCAST breakpoints were used.

Contribution of hypermutation to fosfomycin heteroresistance in Escherichia coli.

Objectives: To explore the effect of combining defects in DNA repair systems with the presence of fosfomycin-resistant mechanisms to explain the mechanisms underlying fosfomycin heteroresistance phenotypes in Enterobacteriaceae.

Materials And Methods: We used 11 clinical Escherichia coli isolates together with isogenic single-gene deletion mutants in the E. coli DNA repair system or associated with fosfomycin resistance, combined with double-gene deletion mutants.