In-vitro susceptibility of Salmonella enterica serovar Typhimurium to reactive oxygen and nitrogen intermediates

Abstract

The aim of this study was to investigate the in-vitro susceptibility of Salmonella enterica serovar Typhimurium against reactive oxygen and nitrogen intermediates, on five different strains. SH5014 as a parental strain, PP120 as a soxRS mutant, SH7616 as a acrAB efflux pump mutant, SZH KUEN 557 as a standard strain and a clinical isolate, were included to the study. Hydrogen peroxide (at 0.125, 0.25, 0.5 mM concentrations) as reactive oxygen intermediate (ROI) and DETA-NO (at 1, 2, 4 mg/ml concentrations) as nitric oxide donor, in addition with acidified sodium nitrite (at 25, 50, 100 mM concentrations) as reactive nitrogen intermediate (RNI) were used. As a result, susceptibility of PP120 to RNI and ROI was found similar with SZH KUEN 557 and the clinical isolate, while SH7616 and SH5014 were found more susceptible than the others. These data indicated that further studies were necessary on the genetic regulatory systems in Salmonella which control the resistance against RNI and ROI-dependent antimicrobial systems.