Enterococcal-type glycopeptide resistance genes in non-enterococcal organisms

Abstract

Although the emergence of vancomycin-resistant enterococci can be attributed, in part, to the increasing use of vancomycin in clinical practice, and glycopeptide use in animal husbandry, the origins of the enterococcal vancomycin resistance genes are not clear. The vancomycin resistance-associated genes in Enterococcus gallinarum, Enterococcus casseliflavus/flavescens, Lactobacillus spp., Leuconostoc spp., Pediococcus spp., and Erysipelothrix rhusiopathiae, are not the source of the high-level vancomycin resistance-associated genes in enterococci. There are, however, environmental organisms which have been found to have gene clusters homologous to the enterococcal vanA, vanB and vanC gene clusters; these include the biopesticide Paenibacillus popilliae, and, to a lesser extent, the glycopeptide-producing organisms Amycolatopsis orientalis and Streptomyces toyocaensis. Still, the exact sources of the enterococcal vancomycin resistance genes remain a mystery.

Leuconostoc, characteristics, use in dairy technology and prospects in functional foods

“…Nevertheless, the use of commercial starter culture bacteria in the production of dairy products could represent a potential for spread of genes encoding resistance to antimicrobial agents; the utilization of antibiotics in animal husbandry, horticulture or industrial processes might contribute to the emergence of antibiotic resistance among human isolates (Patel, 1999;Luh et al, 2000;Teale, 2002); Leuconostoc is recognized as an opportunistic pathogen and antibiotic-resistant strains of Leuconostoc were isolated from infection sites (Kikuchi et al, 1994;Cappelli et al, 1999).…”

“…gellidum, Fleury et al, 1996) so that Leuconostoc strains may constitute a good model for studying bacteriocin gene transfer and evolution. The vancomycin resistance genes in Leuconostoc are not the source of the high-level vancomycin resistanceassociated genes in enterococci as determinants differ (Delcour et al, 1999;Patel, 1999). The complete genome sequence of Lb.…”

Vancomycin‐Resistant Enterococci: Mechanisms and Clinical Observations

“…Another, more closely related group of vanHAX homologues (on the basis of deduced amino acid-sequence homology and content) was found in the vancomycin-G ϩ C [22]. resistant biopesticide Paenibacillus popilliae [30]. The evolutionary lineage of these groups of homologous genes is not clear, but they may have a common, remote ancestor.…”

Antimicrobial Resistance Gene Delivery in Animal Feeds

“…Related vanHAX gene clusters have been identified in Paenibacillus spp. by Patel and coworkers, indicating another possible source of the van cluster ( 20 ). Regardless of the microbial source, the feeding of crude antimicrobial preparations to animals is plausible as a delivery process for transferring the cognate antimicrobial resistance genes between producing strains and the commensal bacteria of animals ( 21 ); the concomitant selection for resistance would ensure the survival of rare resistant strains.…”