are hemotropic bacteria in charge of emerging zoonoses. endothelial cells and in the flea. In this report, we discuss the use of the heme uptake and storage system of during its contamination cycle. Also, we establish a comparison with the iron and heme uptake Plxnc1 systems of used during its contamination cycle. are -proteobacteria that employ arthropods for transmission and erythrocyte parasitism as a common parasitism strategy (Dehio and Sander, 1999; Schulein et al., 2001). Currently, 26 distinct species have been described (Kaiser et al., 2011). are the three most important human pathogens (Dehio, 2005; Florin et al., 2008; Guptill, 2010). Humans are the reservoir host for and (Chomel et al., 2009). causes Oroya fever and verruga peruana (Herrer, 1953a, b). causes trench fever (Vinson et al., 1969). causes cat scrape disease (CSD) and bacillary peliosis (Jones, 1993). Both and can cause bacillary angiomatosis usually in immunodeficient patients (Spach et al., 1995; Sander et al., 1996). and their contamination cycle Each species appears to be transmitted by specific bloodsucking arthropod vectors, and is highly adapted to one or several mammalian reservoir hosts, in which it causes long-lasting intra-erythrocytic bacteremia (Schroder and Dehio, 2005). Intra-erythrocytic bacteremia caused by in the order UK-427857 host has been studied in different rodent models (in rat erythrocytes), which is usually maintained for the remaining lifespan of the infected cell (Schulein et al., 2001). Intra-erythrocytic bacteremia in the and (Koesling et al., 2001; Marignac et al., 2010). Iron/heme uptake in genomes indicated that they neither encode for a siderophore biosynthesis pathway, nor for a complete Fe3+ transport system. genomes encode for homologs of YfeABCD from (Perry et al., 2007) and SitABCD from avian pathogenic genomes encode for a complete heme uptake system. This heme uptake system is comprised of HutA, an outer membrane heme transporter, HutB, HutC, and order UK-427857 HmuV the three components of an inner membrane ABC transporter and a cytoplasmic heme degrading enzyme (HemS) (Parrow et al., 2009; Liu et al., 2012a). HutA from contains the FRAP and NPNL domains conserved in heme transporters like HemR of and HumR of (Parrow et al., 2009). Also, it was shown that HutA from can apparently transport heme when expressed in mutant strain (Parrow et al., 2009). This activity is usually order UK-427857 TonB-dependent (Parrow et al., 2009). and mutants are unable to establish bacteremia in their reservoir hosts. This result suggests that HutA is required for heme uptake in mammals (Saenz et al., 2007; Vayssier-Taussat et al., 2010). After its transport into the cytoplasm, heme must be degraded to release iron. promotes the release of iron from heme when expressed in (Liu et al., 2012a). binds heme and degrades it in the presence of suitable electron donors, such as ascorbate or NADPH-cytochrome P450 reductase (Liu et al., 2012a). Interestingly, HemS activity was shown to be involved in the oxidative stress response of (Liu et al., 2012a). All these above data corroborate previous results demonstrating that can use heme as an iron source (Sander et al., 2000). In is usually repressed by heme in an Irr-dependent manner (Parrow et al., 2009). Over expression of in the presence of heme repress appearance (Parrow et al., 2009). Heme-binding proteins in exhibit 3C5 external membrane heme-binding proteins (Battisti et al., 2006; Battisti and Minnick, 2009). Heme-binding protein of certainly are a band of 30C40 kDa porin-like external membrane protein that absence similarity with known heme receptors (Minnick et al., 2003). HbpA of was proven to bind heme (Carroll et al., 2000). Nevertheless, it didn’t confer a heme-binding phenotype when portrayed in (Carroll et al., 2000). Zimmermann et al., determined a prominent heme-binding proteins Pap31 (HbpA), through a heme-binding blot performed with membrane protein from mutant stress restored its development when heme was added at 30 M and over (Zimmermann et order UK-427857 al., 2003). The experience of HbpA being a heme transporter was questioned by various other authors. Lately, HbpA of was been shown to be unable to go with the mutant in the current presence of heme (Parrow, 2010). Complementation assays.