The mechanism of high-level resistance to vancomycin in enterococci consists of the synthesis of peptidoglycan terminating in D-alanyl-D-lactate instead of the usual D-alanyl-D-alanine. This alternate cell wall biosynthesis pathway is ensured by the collective actions of three enzymes: VanH, VanA, and VanX. The origin of this resistance mechanism is unknown. We have cloned three genes encoding ...

Vancomycin resistance in Enterococcus faecium BM4147 is mediated by vancomycin resistance proteins VanA and VanH. VanA is a D-alanine:D-alanine ligase of altered substrate specificity [Bugg, T. D. H., Dutka-Malen, S., Arthur, M., Courvalin, P., & Walsh, C. T. (1991) Biochemistry 30, 2017-2021], while the sequence of VanH is related to those of alpha-keto acid dehydrogenases [Arthur, M., Molinas...

Inducible resistance to the glycopeptide antibiotic vancomycin requires expression of vanH, vanA and vanX, controlled by a two-component regulatory system consisting of a receptor histidine kinase, VanS, and a response regulator, VanR. The identity of the VanS receptor ligand has been debated. Using a synthesized vancomycin photoaffinity probe, we show that vancomycin directly binds Streptomyce...

Objective: After the increasing number of recent reports hysterectomy by transvaginal natural orifice transluminal endoscopic surgery (vNOTES), we have introduced a novel procedure called vaginally-assisted NOTES (VANH). The objective this study was to describe VANH technique step-by-step, assess technical feasibility procedure, and evaluate its initial surgical outcomes.

AIM The aim of this study was to investigate the VRE frequency and the rate of each gene in isolated enterococci from patients with intestinal infection in the central region of Iran. BACKGROUND Enterococci infections are a public health growing concern due to the glycopeptide antibiotics resistance especially vancomycin. Genes, vanA, B, and H contribute to the influence of vancomycin-resista...

Plasmid pIP816 of Enterococcus faecium BM4147 confers inducible resistance to vancomycin and encodes the VanH dehydrogenase and the VanA ligase for synthesis of depsipeptide-containing peptidoglycan precursors which bind the antibiotic with reduced affinity. We have characterized a cluster of five genes of pIP816 sufficient for peptidoglycan synthesis in the presence of vancomycin. The distal p...

We have previously identified, in Paenibacillus popilliae, a 708-bp sequence which has homology to the sequence of the enterococcal vanA gene. We have performed further studies revealing five genes encoding homologues of VanY, VanZ, VanH, VanA, and VanX in P. popilliae. The predicted amino acid sequences are similar to those in VanA vancomycin-resistant enterococci: 61% identity for VanY, 21% f...

Genes homologous to enterococcal glycopeptide resistance genes vanA and vanB were found in glycopeptide-resistant Paenibacillus and Rhodococcus strains from soil. The putative D-Ala:D-Lac ligase genes in Paenibacillus thiaminolyticus PT-2B1 and Paenibacillus apiarius PA-B2B were closely related to vanA (92 and 87%) and flanked by genes homologous to vanH and vanX in vanA operons.

We assessed the ability of gene transfer to reverse vancomycin resistance in class A (VanA) glycopeptide-resistant Enterococcus faecalis. Recombinant shuttle vectors containing a vanH promoter-vanA antisense gene cassette fully restored vancomycin susceptibility through a combined transcriptional activator binding domain decoy and inducible vanA antisense RNA effect.

The VanA ligase encoded by the vancomycin resistance plasmid pIP816 of Enterococcus faecium BM4147 condenses D-alanine with various D-2-hydroxy and D-2-amino acids in vitro. D-Lactate added to the culture medium restored the vancomycin resistance of a strain that does not produce the VanH dehydrogenase and therefore appears to be a substrate of VanA in vivo.