A widespread deferoxamine-mediated iron-uptake system in Vibrio vulnificus

Vibrio vulnificus can use the standard iron chelator deferoxamine (Desferal) for efficient iron- uptake via the specific receptor DesA, which is encoded by desA. We investigated the ubiquity of the deferoxamine- mediated iron- uptake system in V. vulnificus strains and the potential risk of the system. By polymerase chain reaction (PCR), desA was found in 10 of 10 clinical strains and in 9 of 10 environmental strains, and their growth was stimulated by deferoxamine. By reverse- transcriptase PCR, desA was expressed only under iron- limited conditions containing deferoxamine. V. vulnificus growth in the presence of deferoxamine was suppressed by desA mutation, and the suppressed growth was recovered by desA complementation. Deferoxamine stimulated V. vulnificus growth in iron- limited in vitro and ex vivo backgrounds containing transferrin- bound iron. Overall, V. vulnificus can use transferrin- bound iron via the widespread deferoxamine- mediated iron- uptake system; this cautions that deferoxamine therapy in patients with iron overload may increase the risk of fatal infections caused by V. vulnificus.