Both Decorin-Binding Proteins A and B Are Critical for the Overall Virulence of Borrelia burgdorferi

Abstract

The lack of dbpA alone precluded the pathogen from colonizing the heart tissue, and B. burgdorferi deficient for DbpB was recovered only from 42% of the heart specimens of infected mice. Although B. burgdorferi lacking either dbpA or dbpB was consistently grown from joint specimens of almost all infected mice, it generated bacterial loads significantly lower than the control. The deficiency in either DbpA or DbpB did not reduce the bacterial load in skin, but lack of both significantly did. Taken together, the study results indicate that neither DbpA nor DbpB is essential for mammalian infection but that both are critical for the overall virulence of B. burgdorferi.

A manganese transporter, BB0219 (BmtA), is required for virulence by the Lyme disease spirochete, Borrelia burgdorferi

“…Similarly, Mn, possibly via the Mn-dependent Fur homolog BosR (23,33,37,38) Our study has demonstrated that the Lyme disease spirochete requires BmtA's Mn-associated transport function(s) to maintain its infectious cycle in nature. To date, only relatively few virulence factors, including OspC, DbpB/A, OspA/B, PncA, and BptA, have been identified in Bb, and the functions of most of these proteins remain obscure (4,5,(7)(8)(9)(10). In this regard, our identification of BmtA as a novel virulence factor in Bb provides further insights into molecular mechanisms that contribute to Bb's survival in nature and may lead to new strategies to interrupt the spirochete life cycle.…”

“…In recent years, extensive efforts have been directed toward elucidating the mechanisms by which Bb cycles, adapts, and sustains itself in these diverse niches. It is now well established that outer surface (lipo)protein C (OspC), OspA/B, decorin-binding protein B/A (DbpB/A), PncA, and BptA are required by Bb for efficient infection of ticks or mammalian hosts (4)(5)(6)(7)(8)(9)(10). It is also generally accepted that the recently discovered Rrp2-RpoN ( 54 )-RpoS ( S ) regulatory pathway plays prominently in Bb's virulence expression (11)(12)(13)(14).…”

Transcriptional interplay among the regulators Rrp2, RpoN and RpoS in Borrelia burgdorferi

“…Although a majority (59/98) of genes in this category encode hypothetical proteins and conserved hypothetical (Caimano et al, 2004;Hagman et al, 1998;Shi et al, 2008). In addition, eight genes encoding proteins related to chemotaxis were found to be induced by Rrp2, RpoN and RpoS.…”

“…Several plasmids, such as lp25, lp28-1 and lp36, are essential for borrelial infectivity (Jewett et al, 2007;Purser & Norris, 2000;Stewart et al, 2005). Plasmid lp54 has been implicated as being important for the survival of B. burgdorferi in both tick and mammalian hosts, largely because of the presence of the ospAB and dbpBA operons (Caimano et al, 2005;Hagman et al, 1998;Neelakanta et al, 2007;Shi et al, 2008;Yang et al, 2004). Many other genes encoded on lp54 have been found to be differentially regulated in response to temperature, pH and other mammalian-derived signals, which are presumed to be mediated, at least in part, by RpoS (Caimano et al, 2005;Clifton et al, 2006;Ojaimi et al, 2003;Revel et al, 2002).…”

“…To date, only relatively few virulence factors in B. burgdorferi, such as OspAB, OspC, DbpBA and BBK32, have been determined definitively to be under the regulatory control of this pathway (Grimm et al, 2004;Hagman et al, 1998;Neelakanta et al, 2007;Pal et al, 2004;Seshu et al, 2006;Shi et al, 2008;Yang et al, 2004). As such, continued efforts are warranted to elucidate other potential B. burgdorferi virulence factors.…”