Enterotoxin Production and Plasmid Detection of Citrate Utilizing Escherichia coli Isolated from Cattle

우(牛) 유래(由來) Citrate이용(利用) 대장균(大腸菌)의 장독소(腸毒素) 산생능(産生能) 및 Plasmid DNA

  • Chae, Tae-chul (College of Veterinary Medicine, Kyungpook National University) ;
  • Choi, Won-pil (College of Veterinary Medicine, Kyungpook National University)
  • 채태철 (경북대학교 수의과대학) ;
  • 최원필 (경북대학교 수의과대학)
  • Received : 1988.01.25
  • Published : 1988.04.30


This paper deals with the 0 groups of citrate utilizing variants of Escherichia coli ($Cit^+$ E. coli) isolated from cattle, the production of colicin, hemolysin, K99 antigen, heat stable enterotoxin, and the isolation of plasmid DNA. Among 42 $Cit^+$ E. coli, 12 strains were 020, 9 strains 08, 5 strains 045, 3 strains 0115, 1 strain 064, 1 strain 0139 and remaining strains(11) were untypable. Thirty-nine(81.3%) out of 48 $Cit^+$ E. coli were produced colicin and 13(27.0%) were produced hemolysin. Of 12 $Cit^+$ E. coli bearing K99 antigen, 6(50.0%) were produced heat stable enterotoxin. In gel electrophoresis for the isolation of plasmid DNA, the number of plasmids varied from 1 to 7 in 10 $Cit^+$ E. coli. It's molecular weight ranged from 2 to 50 Mdalton, and 50 Mdalton plasmid was commonly existed in all strains.