1. Siderophore production and roles in virulence in K. pneumoniae.
Siderophore production and roles in virulence in K. pneumoniae. The ability to acquire iron in an iron-poor environment during infection is necessary for K. pneumoniae pathogenesis. Therefore, bacteria secrete proteins with a high affinity for iron, called siderophores. K. pneumoniae strains have been found to produce one or more of the following siderophores: enterobactin, salmochelin, yersiniabactin, and aerobactin. Enterobactin is the primary siderophore used by K. pneumoniae, although it is inhibited by the host molecule lipocalin-2. Salmochelin is a c-glucosylated form of enterobactin that can no longer be inhibited by lipocalin-2. Yersiniabactin and aerobactin are structurally distinct from enterobactin and salmochelin. Neither siderophore can be inhibited by lipocalin-2, but yersiniabactin functionality is reduced in the presence of the host molecule transferrin. The production of a number of different siderophores may allow K. pneumoniae to colonize and disseminate to a number of different sites within the host, with niche-specific roles for each siderophore. FepA, IroN, YbtQ, and IutA serve as transporters specific to their corresponding siderophores of enterobactin, salmochelin, yersiniabactin, and aerobactin, respectively.
Michelle K. Paczosa, and Joan Mecsas Microbiol. Mol. Biol. Rev. 2016; doi: /MMBR