• 作者： 楊美桂; 譚棉心
• 作者服務機構： 輔仁大學生物系
• 中文摘要： 利用大腸桿菌毒素LT基因為探針，以菌落雜交反應由55株鼠傷寒桿菌分離株中，選出5株呈正反應，其中4株的
  菌體抽取物，能?造成白兔皮膚明顯的腫脹，也可使CHO細胞拉長，並影響其生長與分裂，亦即有毒素的產生；由於細
  菌培養上清液無此效應，且菌體抽出液經100℃加熱30分鐘失去其毒素作用，故知分離之鼠傷寒桿菌可產生非分泌性之
  懼熱毒素。
  由雜交反應與毒素活性測定呈正反應之5株菌，抽取其染色體及質體DNA，以LT基因探針測得毒素基因位於特殊質
  體上。將質體以BanHI，EcoRI，HindIII與PstI等限制?作用，利用雜交反應，選出了三段含有毒素基因的DNA片段，
  其大小為5.2,5.0及8.6Kb，分別來自22號，52號與59號鼠傷寒桿菌的質體，將此三段DNA以pUC19為載體，送入大
  腸桿菌JM101，並選出轉形菌，以大腸菌毒素基因為探針，測得毒素基因之存在，並利用白兔皮膚滲透性試驗，確定毒素
  之產生。A
• 英文摘要： Five of fifty five strains of Salmonella typhimurium of human origin were hybridized with boththe LT-A and LT-B gene of Escherichia coli. The remarkably erythromatous and indurated response onrabbit skin and significant elongation of Chinese Hamster Ovary (CHO) cells indicated the production ofenterotoxin of these isolates. The Salmonella enterotoxin is heat-labile and is not a secretory product. The LT gene of E coli was used to analyze the chromosome and plasmid DNA from Salmonellatyphimurium strains for toxin gene sequences. Southern blot analysis demonstrated that the toxin genewas located on the plasmid but not on the chromosome. Restriction enzymes BamHI, EcoRI, HindIIIand PstI were used to analyze the DNA isolated from salmonella strains Nos.22, 52, 55 and 59. Three DNAfragments with size of 5.2 Kb of strain 22, 5.0 Kb of strain 52 and 8.6 Kb of strain 59 were identified ascontaining the enterotoxin gene. Plasmid pUC19 was used as the vector to clone these DNA fragments inE. coli. The rabbit skin permeability test indicated that Salmonella enterotoxin could be synthesized atreadily detectable levels in these transformed E. coli.
• 中文關鍵字： Salmonella typhimurium; enterotoxin; gene cloning
• 英文關鍵字： --