Vancomycin-resistant enterococci: consequences for therapy and infection control

Abstract

Vancomycin-resistant enterococci (VRE) have emerged as important nosocomial pathogens, initially in the USA, but now also in Europe, where hospital outbreaks are being reported with increasing frequency, although the incidence of VRE infections remains extremely low in most European countries. The recently demonstrated in-human transmission of vancomycin resistance from VRE to methicillin-resistant Staphylococcus aureus (MRSA) in two American patients underscores the potential danger of a coexisting reservoir of both pathogens. As MRSA is already endemic in many European hospital settings, prevention of endemicity with VRE seems relevant, but should be balanced against the costs associated with the implementation of effective strategies. The presence of a large community reservoir of VRE in Europe could hamper the feasibility of infection control strategies. Although the prevalence of colonisation amongst healthy subjects has apparently decreased after the ban on avoparcin use in the agricultural industry, a large proportion of admitted patients are still potential sources of VRE transmission. With no risk profile available to identify these carriers, effective screening, followed by barrier precautions for carriers, seems to be impossible. Recent studies, however, have suggested that hospital outbreaks are almost exclusively caused by specific genogroups of VRE that can be characterised phenotypically and genotypically (e.g., co-resistance to ampicillin and the presence of the variant esp gene). Based on our own experience, we propose that VRE infection control programmes should be restricted to patients colonised with these VRE strains. If such a strain is cultured from a clinical sample, surveillance amongst contact patients is recommended and barrier precautions should be implemented in the case of documented spread.

Current Trends in Rapid Diagnostics for Methicillin-Resistant Staphylococcus aureus and Glycopeptide-Resistant Enterococcus Species

“…The incidence of GRE infections in European hospitals is currently low. However, asymptomatic carriage in healthy individuals is common (reviewed in reference 28), and a recent report of an in vivo transmission of vancomycin resistance from GRE to MRSA underscores the potential danger of a coexisting reservoir of both pathogens (5). Resistance to glycopeptides is mediated by the van gene clusters, which produce resistance by altering the drug target from D-alanine-D-alanine to D-alanine-D-lactate (reviewed in reference 9).…”

Analysis of Antibiotic Resistance Genes in Multidrug-Resistant Acinetobacter sp. Isolates from Military and Civilian Patients Treated at the Walter Reed Army Medical Center

“…This reservoir would serve to widely disseminate MDR Acinetobacter spp. As has been seen with methicillin-resistant Staphylococcus aureus isolates and vancomycin-resistant enterococci (VRE), patients who are colonized can spread MDR pathogens (5,6,30).…”

Waste water treatment plants as redistributors of resistance genes in bacteria

“…Isolates of Enterococcus faecalis and Enterococcus faecium are the third-to fourth-most prevalent nosocomial pathogen worldwide [20]. Antimicrobial resistance in strains causing nosocomial infections is a growing problem and VRE in particular are considered a serious threat in hospitals around the world [21]. Vancomycin is often used as a last resort in treatment of antibiotic resistant gram-positive bacterial infections caused by organisms such as multi-resistant enterococci and methicillin resistant staphylococci.…”