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Persistence of vanA-type Enterococcus faecium in Korean livestock after ban on avoparcin
Suk-Kyung Lim1, Tae-Soon Kim, Hee-Soo Lee
1National Veterinary Research and Quarantine Service, Anyang, Republic of Korea.
Abstract:
Prevalence of vancomycin-resistant enterococci (VRE) was investigated in Korean livestock 4 years after the ban of avoparcin in feed additives. VRE were isolated from approximately 16.7% of the chicken samples (57 strains from 342 meat samples) and 1.9% of the pig samples (4 from 214 fecal samples). No VRE, however, was isolated from 110 bovine fecal samples. All the 61 VRE isolates were vanA-type Enterococcus faecium expressing a high-level resistance to vancomycin, and showed resistance to teicoplanin as well except two poultry isolates. In addition, the VRE isolates had heterogeneous pulsed-field gel electrophoresis (PFGE) patterns of SmaI-digested DNA, although identical or closely related profiles were observed among strains isolated from the same farm. Although the chicken isolates were all poultry type with G at position 8,234 of the vanX gene, the pig isolates were all swine type with T at position 8,234 of the vanX gene.
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