Occurrence and Relatedness of Vancomycin-Resistant Enterococci in Animals, Humans, and the Environment in Different European Regions

Abstract

Vancomycin-resistant enterococcci (VRE) in Europe are thought to have emerged partly due to the use of the glycopeptide avoparcin in animal husbandry. We compared the occurrence of VRE in geographical regions of Europe in which until 1997 large amounts of avoparcin were used (Spain, United Kingdom, and Denmark) with the occurrence of VRE in Sweden, where avoparcin was banned in 1986. We also studied the relatedness between VRE strains from different regions and habitats. In total, 2,580 samples were collected from humans, animals, and the environment (soil, sewage, recipient water). VRE resistant to 20 g/ml vancomycin were identified in 8.2% of the samples and were found most frequently in raw and treated urban sewage samples (means, 71% and 36% of the samples, respectively), pig manure (17%), and hospital sewage (16%). The proportions of VRE-positive sewage samples were similar in Sweden, Spain, and the United Kingdom, whereas pig feces and manure were more often positive in Spain than in Sweden (30% versus 1%). Most VRE were Enterococcus faecium carrying vanA, and computerized biochemical phenotyping of the isolates of different ecological origins showed a high degree of polyclonality. In conclusion, it seems that animal-associated VRE probably reflect the former use of avoparcin in animal production, whereas VRE in human-associated samples may be a result of antibiotic use in hospitals. Since there seems to be a reservoir of the resistance genes in all countries studied, precautions must be taken to limit the use of antibiotics and antibiotic-like feed additives.Enterococci are members of the normal intestinal microflora in humans and animals, and they are common in environments affected by animal and human fecal material. These organisms are not considered primary pathogens, but because of their ability to acquire high-level resistance to antimicrobial agents enterococci have emerged as nosocomial pathogens worldwide (30). Concern has especially been focused on enterococci that show high-level resistance to the glycopeptide antibiotic vancomycin (vancomycin-resistant enterococci [VRE]), which until recently has been the drug of last resort against multiresistant enterococci and against methicillin-resistant Staphylococcus aureus.In the United States, the incidence of bloodstream infection due to VRE increased from 0.4% in 1989 to 25.2% in 1999 (35), and between 15 and 24% of the hospitalized patients were reported to be colonized with VRE in 1998 (33). A later report indicated that 15% of all clinically relevant isolates of gram-positive cocci were VRE (17), whereas VRE of the VanA and VanB types have not been reported in animals so far. Thus, in the United States VRE are thought to have emerged and spread entirely as a result of the antibiotic use in hospitals. In Europe, infections caused by VRE remain a moderate problem in most countries. A European surveillance study found VRE in 7% of enterococcal isolates from blood cultures (13). On the other hand, healthy carriers of VRE in the community are relativ...

Antibiotic Susceptibility Pattern and Virulence Genes in Enterococcus spp. Isolated From Clinical Samples of Milad Hospital of Tehran, Iran

“…The study by Gambarotto et al showed that the prevalence of VRE in hematology patients was about 37% (25). Kuhn et al showed that the prevalence of VRE isolated from animals, humans and the environment in different European regions was in the range of 8% -11% (16).…”

“…Enterococcus spp. may carry various genes that directly or indirectly contribute to virulence (15,16).…”

Inhibitory Impact of Bifidobacteria on the Transfer of β-Lactam Resistance among Enterobacteriaceae in the Gnotobiotic Mouse Digestive Tract

“…In hospital settings, multidrug-resistant bacteria are being isolated at an increasing rate and are having a significant impact on clinical practice and overall treatment cost (7,15). Furthermore, in the community, a pool of antibiotic-resistant bacteria exists that either originates from hospital reservoirs or is a consequence of the use of antimicrobial substances in animals (14).…”

vanA in vancomycin-resistant Enterococcus faecalis isolated in Baghdad

“…In our study, 25% of clinical isolate and 66.7% of stool isolate were resistant to vancomycin, these results agreed with those of other results (Al Kafaji, 2005), but in disagreement with that of (Alsaadi, 2007) which showed that all isolates of E. faecalis were sensitive to vancomycin but in the study of (Kandela, 2006) the resistance was higher the current study. Kühn et al, (2005) studied the occurrence of VRE in 2 580 samples collected in different geographical regions in Europe, high proportions of VRE-positive urban sewage samples were found in Sweden, Spain, and the United Kingdom (52 to 90%), apparently reflecting a human source rather than an animal source; despite the fact that the consumption of antibiotics in hospitals in Sweden (population, 9 million) is among the lowest in Europe. Thus, it is possible that antibiotic-resistant enterococci present in the human population are enriched in hospitals, released from there into municipal sewers to become established, and then further released via sewage treatment plants into recipient water and transferred back into humans.…”