Isolation of Escherichia coli O157:H7 from animal feces and biochemical characteristics of Verotoxin-2 produced by these strains I. Study on the phages related to production of Verotoxin-2, and Isolation of Escherichia coli O157:H7 from feces of cattle and pigs

동물분변에서 Escherichia coli O157:H7의 분리 및 이들 균이 생산하는 Verotoxin-2의 생물화학적 특성 I. 소와 돼지의 분변에서 E coli O157:H7의 분리 및 Verotoxin-2 생산에 관여하여 파아지의 분리에 관하여

  • Cha, In-ho (Pusan Institute of Health and Environment) ;
  • Kim, Yong-hwan (College of Veterinary Kyeongsang National University)
  • 차인호 (부산시보건환경연구원) ;
  • 김용환 (경상대학교 수의과대학)
  • Received : 1995.12.15
  • Published : 1996.06.25


Three and 2 strains of E coli O157 were isolated from fecal materials of cattle (390) and pigs (420) in Korea, respectively. One strain of O157:H7 isolated from cattle and 2 strains of O157:H7 isolated from pigs were identified as verotoxin-1 (VT-1) produing strains and 2 strains (O157:H7 and O157:H-) isolated from cattle were identified as verotoxin-2 (VT-2) producing strains by neutralization test on HeLa and Vero cells. Culture supernatants of the isolates were cytotoxic to HeLa and Vero cells. The levels of cytotoxin produced by isolates were $10^2{\sim}10^4$ cytotoxic dose($CD_{50}$)/ml. Also, VT-2-converting bacteriophage was isolated from KSC109 strain which had been isolated from cattle. Molecular weight of the phage DNA was determined as approximately 45 Kb in 0.8% agarose gel electrophoresis, and morphology of the phage stained with phosphotungstic acid was observed by transmissible electron microscopy.