Olsvik O, Fossum K
Acta Vet Scand. 1984;25(1):21-8. doi: 10.1186/BF03547275.
Thirty-two Escherichia coli colonies were taken from the primary step of cultivation of the jejunal contents of each of 10 dead piglets which had suffered from diarrhea. The organisms of each colony were examined for the presence of adhesion fimbria (F4 (K88) and F5 (K99)), production of heat-stable and heat-labile enterotoxin and of colicins. The presence of heat-labile enterotoxin in the intestinal content of the necropsied pigs was also tested, and results correlated with enterotoxin production of the isolated E. coli strains. In all but 3 pigs, 50–80 % of the E. coli strains were found to produce one or both of the enterotoxins and to possess the F4 of the F5 antigen. All bacteria producing both heat-labile and heat-stable enterotoxin proved to belong toi O group 149 and to possess the F4 antigen. Strains from 1 pig belonged to O group 64 and possessed the F5 antigen; these bacteria produced heat-stable enterotoxin only. Most of the enterotoxin-producing E. coli also produced colicins. After each subcultivation, the strains produced less heat-labile enterotoxin, some becoming negative when assayed.
从10头死于腹泻的仔猪空肠内容物初代培养物中选取32个大肠杆菌菌落。检测每个菌落的细菌是否存在黏附菌毛（F4（K88）和F5（K99））、是否产生热稳定和热不稳定肠毒素以及是否产生大肠杆菌素。还检测了剖检猪肠道内容物中热不稳定肠毒素的存在情况，并将结果与分离出的大肠杆菌菌株的肠毒素产生情况进行关联。除3头猪外，在所有猪中，发现50%至80%的大肠杆菌菌株产生一种或两种肠毒素，并具有F4或F5抗原。所有产生热不稳定和热稳定肠毒素的细菌均属于O149群，并具有F4抗原。来自1头猪的菌株属于O64群，并具有F5抗原；这些细菌仅产生热稳定肠毒素。大多数产生肠毒素的大肠杆菌也产生大肠杆菌素。每次传代培养后，菌株产生的热不稳定肠毒素减少，一些在检测时变为阴性。
