Antibacterial activity of a combination of cysteine and ciprofloxacin and its relationship with the generation of oxidative stress in extended-spectrum betalactamase-producing escherichia coli strains

Abstract

The aim of the present work was to evaluate whether L-cysteine enhances theantibiotic susceptibility of extended-spectrum beta-lactamase (ESBL) Escherichia coli strains to ciprofloxacin and to identify the role of Reactive oxygen species (ROS) in the antimicrobial activity.The combined ef5fect of L-cysteine and ciprofloxacin was investigated by the macrodilution broth method and chemiluminescence assay. ESBL 1 and ESBL 2 strains presented a growth inhibition when they were incubated with 0.4 or 0.2 mM of cysteine, respectively compared to the control without antibiotic. Both strains at sub-inhibitory concentration of ciprofloxacin were combined withcysteine, and a clear growth inhibition respect to the control was observed. An increase of 68% in ROS occurred respect to the control when ESBL 1 was treated with a combination of ciprofloxacin and cysteine, while for ESBL 2 there was a rice of 127 %. The combination of ciprofloxacin with cysteine had the capacity to undergo redox cycling and ROS production with subsequent cellularinjury.Fil: Martínez, S. R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Bongiovanni, M. E.. Hospital Privado Centro Medico de Córdoba; ArgentinaFil: Piersigilli, Andrea Laura. Sanatorio Aconcagua; ArgentinaFil: Albesa, Inés. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; ArgentinaFil: Becerra, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; Argentin