Regulation of VanB-type vancomycin resistance gene expression by the VanS(B)-VanR (B) two-component regulatory system in Enterococcus faecalis V583

Glycopeptide-resistant enterococci: a decade of experience

“…However, on Tn1547, vanYB and vanW are both located between the regulatory genes (see below) and the vanHBBXB essential genes (Fig. 2) [50]. The position of these two genes upstream of the essential genes suggests that they may play a more significant role in the expression of VanB resistance than that played by vanY and van2 in VanA resistance.…”

Comparative analysis of two-component signal transduction systems of Bacillus cereus, Bacillus thuringiensis and Bacillus anthracis

“…Maintaining an E-value cut-off of 1610 215 , we found a number of B. cereus group TCSs to be similar to systems with a known biological function (Table 2). Among the functionally defined systems, many are known to respond to cell-wall-acting antibiotics or general cellenvelope stresses, such as CesKR, CroSR, VanSR, VanSR b and VraSR (Arthur & Quintiliani, 2001;Comenge et al, 2003;Evers & Courvalin, 1996;Kallipolitis et al, 2003;Kuroda et al, 2000), and many are known to function in lantibiotic production and resistance, such as SpaKR, NisKR, BacSR and SalKR (Engelke et al, 1994;Klein et al, 1993;Neumuller et al, 2001;Upton et al, 2001). …”

Healthcare associated vancomycin- resistant enterococci

“…VanBglycopeptide resistancein enterococci is mediated by an abnormal ligase (VanB) that is structurally related to VanA(76% amino acid identity).VanB protein also favors the production of the pentadepsipeptide terminating in D-Ala-D-Lac [40].Genes analogous to their class A resistance counterparts are designated vanH B ,vanX B ,vanY B ,vanR B ,andvanS B [41].Levels of D,D-dipeptidase activity (vanXB) correlates with levels of vancomycin resistance [42].There is high degree of sequence identity(approximately 70%)between vanHAX and vanHBBXB but considerably less homology(25 to 35% sequence homology) between RS and Y proteins of VanA and VanBVRE [42].There is no gene counterpart of vanZ in these organisms.vanY B is not found in all strains, and its position in the gene clusters differs from that of vanYinTn1546 [43].Recent reports have shown DNA sequence heterogeneity, suggesting three subtypes of vanB ligase gene:vanB-1,vanB-2.andvanB3 [44].the regulatory system in class B strains appears insensitive to induction by teicoplanin [42,rept].Teicoplanin induces the synthesis of VanA-related proteins but does not induce the production ofVanB-related proteins.On the other hand,vancomycin induces the synthesis of the resistance proteins of both systems ,and in fact, if a teicoplanin susceptible enterococcus with vanB gene cluster is preexposed to vancomycin,the strain then tests teicoplanin resistant as well. In addition,teicoplanin-resistant mutants can be derived from teicoplanin-susceptible, vanBcontaining enterococci when these organisms are plated onto teicoplanin containing agar.…”