Salmonella Newport siderophore receptor protein (SRP) (SRP)

Salmonella Newport siderophore receptor proteins (SRPs) are critical outer membrane transporters that enable the bacterium to acquire iron, an essential nutrient for its survival and pathogenesis (UniProt, 2024). In the host environment, iron is strictly sequestered by proteins like transferrin, prompting Salmonella to secrete high-affinity chelators called siderophores to capture ferric iron (PubMed: 19172021). The SRPs, including specific receptors such as FepA, IroN, and FhuA, recognize and transport these iron-siderophore complexes across the outer membrane into the periplasm (PubMed: 16233008). These proteins are the primary target of Siderophore Receptor and Porin (SRP) vaccine technology, which is widely used in veterinary medicine to control Salmonella Newport infections in cattle and poultry (USDA, 2023). By inducing the production of antibodies that bind to these receptors, the vaccine physically blocks iron acquisition, effectively "starving" the bacteria and inhibiting their replication (PubMed: 15933154). This immunological blockade not only reduces the clinical severity of the infection but also significantly decreases the environmental shedding of the pathogen, which is a major factor in foodborne disease transmission. Beyond vaccines, these receptors are also being investigated as targets for "Trojan horse" antimicrobial strategies, where siderophore-antibiotic conjugates are used to bypass traditional resistance mechanisms (PubMed: 30254015). Overall, Salmonella Newport SRPs represent a vital target for improving both animal health and human food safety.

Other names

Siderophore receptor and porin proteinsIron-regulated outer membrane proteinsIROMPsSRPsFerric enterobactin receptorFepASalmochelin receptorIroNFerrichrome receptorFhuA

Induction of antibodies that bind to and block outer membrane siderophore receptors, preventing the uptake of essential iron and inhibiting bacterial replication.