Evidence of a novel gene from Aeromonas hydrophila encoding a putative siderophore receptor involved in bacterial growth and survival

The pathogenic bacterium Aeromonas hydrophila has been shown to exclusively utilize a ligand exchange mechanism for siderophore-mediated iron uptake, with a single nonspecific siderophore receptor facilitating iron exchange. However, the genes involved in this process, including the gene encoding the nonspecific receptor, are unknown. Here we identify and characterize a novel gene, nsrl, from A. hydrophila that encodes a putative protein with high homology and significant predicted structural similarities to the FhuA protein and other known ferric-siderophore receptors. This protein appears to localize on the cell membrane and is likely to be the receptor involved in the ligand exchange siderophore-mediated iron uptake mechanism of A. hydrophila. It is expected that this information may lead to e development of new antibiotics targeting either nsrl or its gene product for use in controlling A. hydrophila infection.