Occurrence and relatedness of vancomycin-resistant enterococci in animals, humans, and the environment in different European regions.
Vancomycin-resistant enterococci (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 microg/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.
Kühn
Inger
I
Microbiology and Tumor Biology Center, Karolinska Institutet, Box 280, SE-171 77 Stockholm, Sweden. inger.kuhn@mtc.ki.se
Iversen
Aina
A
Finn
Maria
M
Greko
Christina
C
Burman
Lars G
LG
Blanch
Anicet R
AR
Vilanova
Xavier
X
Manero
Albert
A
Taylor
Huw
H
Caplin
Jonathan
J
Domínguez
Lucas
L
Herrero
Inmaculada A
IA
Moreno
Miguel A
MA
Möllby
Roland
R
D000822:Animal Husbandry; D000818:Animals; D000829:Animals, Domestic / Q000382:microbiology*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D016983:Enterococcus / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification*; D004783:Environmental Microbiology; D005060:Europe; D005243:Feces / Q000382:microbiology; D006020:Glycopeptides; D006761:Hospitals; D006801:Humans; D008826:Microbial Sensitivity Tests; D012722:Sewage / Q000382:microbiology*; D020713:Vancomycin Resistance
D000900:Anti-Bacterial Agents; D006020:Glycopeptides; D012722:Sewage; C016249:avoparcin