Characteristics of verotoxin non-producing Escherichia coli O157 and verotoxin-producing E coli isolated from healthy cattle

정상 소 분변에서 분리한 verotoxin을 산생하지 않는 Escherichia coli O157과 verotoxin을 산생하는 E coli의 특성 조사

  • Jung, Byeong-yeal (Bacteriology Division, National Veterinary Research and Quarantine Service) ;
  • Jung, Suk-chan (Bacteriology Division, National Veterinary Research and Quarantine Service) ;
  • Park, Hong-je (Microbiological Research Institute, KOMED) ;
  • Cho, Gil-jae (Equine Hospital, Korea Racing Association) ;
  • Kim, Bong-hwan (College of Veterinary Medicine, Kyungpook National University)
  • 정병열 (국립수의과학검역원 세균과) ;
  • 정석찬 (국립수의과학검역원 세균과) ;
  • 박홍제 ((주)코메드 미생물연구소) ;
  • 조길재 (한국마사회 마필보건소) ;
  • 김봉환 (경북대학교 수의과대학)
  • Received : 2000.07.27
  • Published : 2000.09.25

Abstract

Verotoxin non-producing E coli O157 strains have been isolated from cattle feces and compared in particular regard to biochemical properties and genotypes with verotoxin-producing E coli (VTEC). E coli O157 : nonH7 strains had different phenotypes in sorbitol fermentation and ${\beta}-glucuronidase$ activity from E coli O157 : H7. Regardless of verotoxin production ability of E coli O157 : H7, uidA gene was uniquely detected from sorbitol and ${\beta}-glucuronidase$ negative E coli O157 : H7. Forty five fecal samples from 6 dairy farms were obtained and VTEC was detected as 15.6% (7 strains) of the samples. Most VTEC isolates were positive for sorbitol fermentation and ${\beta}-glucuronidase$ activity but negative for eaeA gene. This study suggested that cattle could be a reservior for VTEC. However, absence of eaeA gene in VTEC isolates from most of healthy cattle suggested that they might be less virulent than eaeA-positive E coli against human health.