Identification and characterization of vanB2 glycopeptide resistance elements in enterococci isolated in Scotland

Thirty-two vanB glycopeptide-resistant enterococci (28 Enterococcus faecium and 4 Enterococcus faecalis) were collected from hospitalized patients in Glasgow, Edinburgh, Dundee, acid Aberdeen, Scotland, and the vanB element i n each was compared to vanB1 of E. faecalis strain ATCC 51299, HhaI digesti on of PCR fragments of the vanB ligase gene was used to identify vanB subty pes. All E, faecium isolates were vanB2, and all E. faecalis isolates were vanB1. Restriction fragment length polymorphism analysis of a 5,180-bp vanS (B)-vanX(B) long-PCR fragment of the vanB cluster showed the loss of HaeII restriction sites in vanS(B), vanW, and vanX(B) in strains containing a van B2 ligase gene. Partial sequences of genes in the vanB2 cluster for two gen omically distinct Scottish isolates were >99.8% identical to each other. va nS(B2), vanX(B2), and vanB2 sequences differed at the nncleotide level from those of vanS(B), vanX(B), and vanB by 4.2, 4.6, and 48%, respectively. Th e vanB2 resistance element appears to be widespread among VanB glycopeptide -resistant E. faecium strains isolated in Scottish hospitals.