Detection of a Novel gyrB Mutation Associated with Fluoroquinolone-Nonsusceptible Salmonella enterica serovar Typhimurium Isolated from a Bloodstream Infection in Ghana

A multidrug-resistant Salmonella enterica serovar Typhimurium with reduced susceptibility to ciprofloxacin was isolated from the blood of a hospitalized child in Ghana. DNA sequencing identified a novel gyrB mutation at codon 466 (Glu466Asp). An increase in fluoroquinolone susceptibility after the introduction of a wild-type gyrB+ allele demonstrated that the gyrB466 mutation had a direct effect on fluoroquinolone susceptibility.