Dubey R S, Sanyal S C
J Med Microbiol. 1979 Aug;12(3):347-54. doi: 10.1099/00222615-12-3-347.
Cell-free culture filtrates and crude enterotoxin preparations from six strains of Aeromonas hydrophila caused the accumulation of fluid in rabbit ileal loops. This activity was due to a non-dialysable, heat and acid-labile antigenic protein and was lost when culture filtrates and crude enterotoxin preparations were heated at 60 degrees C for 20 min. or 56 degrees C for 30 min. respectively. Maximum activity was observed at pH 8.0-10.0; there was a gradual loss at lower pH and activity was abolished in culture filtrates held at pH 3.0 and crude enterotoxin preparations held at pH 4.0. Titration of the crude enterotoxin preparations in rabbit ileal loops showed that the ED50 (equivalent to 1 unit of toxin) was contained in 25 microgram of protein; a logarithmic plot of the neutralisation coefficients against antiserum concentrations showed that one unit of antitoxin was contained in 42 x 10(-4) ml of the antiserum.
六株嗜水气单胞菌的无细胞培养滤液和粗制肠毒素制剂可使兔回肠肠袢积液。这种活性归因于一种不可透析、对热和酸不稳定的抗原性蛋白质，当培养滤液和粗制肠毒素制剂分别在60℃加热20分钟或56℃加热30分钟时，活性丧失。在pH 8.0 - 10.0时观察到最大活性；在较低pH值时活性逐渐丧失，在pH 3.0的培养滤液和pH 4.0的粗制肠毒素制剂中活性被消除。在兔回肠肠袢中对粗制肠毒素制剂进行滴定表明，25微克蛋白质中含有ED50（相当于1个毒素单位）；针对抗血清浓度的中和系数对数图显示，42×10⁻⁴毫升抗血清中含有1个抗毒素单位。
