In vitro time-kill activities of ciprofloxacin alone and in combination with the iron chelator deferasirox against Vibrio vulnificus

Abstract

Iron plays a major role in the growth and virulence of ferrophilic organisms like Vibrio vulnificus. People who reside in the coastal areas with raw fish eating habits have a high risk of Vibrio infection and aggressive therapy can only reduce their mortality. We investigated the in vitro efficacy of ciprofloxacin, a bactericidal drug used in V. vulnificus patients, and the orally active iron chelator deferasirox against V. vulnificus infection. We performed in vitro time-kill studies on two ATCC strains and one clinical isolate of V. vulnificus collected from a patient admitted to Chosun University Hospital with either ciprofloxacin or iron chelator deferasirox alone and the two drugs in combination. The combination of an iron chelator plus an antibiotic creates a novel form of synergism at 24 h. The antimicrobial effect of deferasirox may be ascribed to its ability to deplete iron that would otherwise be used for bacterial growth. Combination therapy with ciprofloxacin plus deferasirox has potential clinical application by lowering the iron availability against a ferrophilic organism like V. vulnificus infections.