Siderophores and Pathogenecity of Microorganisms

Introduction: The ability of pathogenic microorganisms of obtaining iron from host is essential for its survival. Microorganisms require iron for a variety of metabolic processes, so they synthesize and secrete small organic molecules called siderophores that actively chelate iron. The study was carried out to compare the results of siderophore produced by commensals & clinical isolates and co-relate it to pathogenecity. Materials & Methods: Detection of microbial siderophore production was carried out qualitatively by the chrome azurol sulfonate (CAS) plate assay. Spectrophotometric assay (Liquid CAS assay) was used for quantitative estimation of siderophore produced by the organisms. Qualitative assay for determining type of siderophore was also carried by Arnow’s & Csaky’s methods. Results: The commensals & the isolates from clinical samples did not show any significant difference in the production of siderophore. It was also observed that the optimum condition for siderophore production by both the commensals & the clinical isolates was at 370C for 24 hours with aeration in an iron deficient medium. Conclusion: One cannot use siderophore production as a determinant of virulence of an organism. Thus, it is concluded that siderophore production may be a necessary feature of a bacterium, but not a determinant of virulence. The siderophore producing potential of a pathogen in vivo cannot be decided on basis of in-vitro assays. But applications of siderophores could be many if well studied.