Tzipori S, Chandler D, Smith M, Makin T, Halpin C
Aust Vet J. 1982 Sep;59(3):93-5. doi: 10.1111/j.1751-0813.1982.tb02736.x.
Three strains of enterotoxigenic Escherichia coli (ETEC) (064:KSNT, K88ac; 020:KSNT, K88ac and 08:K85ab, K99) originally cultured from outbreaks of diarrhoea in piglets a few hours old, were administered orally to gnotobiotic piglets. There was a marked age-related difference in the clinical response to infection between the 3 strains although they all produced heat-stable toxin. All 3 strains produced severe clinical signs of depression, anorexia, vomiting, diarrhoea, followed by dehydration and death in one-day-old piglets. In piglets infected at 3 days of age the two K88+ ETEC caused diarrhoea and death but the K99+ ETEC induced moderate diarrhoea only. In piglets infected at 7 days of age, the 064 strain produced severe diarrhoea and death, and 020 strain caused mild diarrhoea in 3 of 6 piglets with one death while the 08 strain caused no illness. Pathological changes in the intestinal tract associated with these infections were minimal, or absent. Immunofluorescent staining with homologous hyperimmune sera demonstrated adherence of the 3 ETEC strains to the brush border of small intestinal epithelial cells. Fluorescing organisms were observed in all infected piglets irrespective of the severity of clinical signs but the degree and extent of colonisation varied with the age of the piglets and the infecting strain. This may explain the difference in clinical response between the 3 strains.
从出生几小时的仔猪腹泻暴发中最初分离出的三株产肠毒素大肠杆菌（ETEC）（064:KSNT，K88ac；020:KSNT，K88ac和08:K85ab，K99），经口给予无菌仔猪。尽管这三株菌均产生耐热毒素，但它们对感染的临床反应存在明显的年龄相关性差异。所有三株菌在1日龄仔猪中均引起严重的临床症状，包括精神沉郁、厌食、呕吐、腹泻，随后出现脱水和死亡。在3日龄感染的仔猪中，两株K88+ ETEC引起腹泻和死亡，但K99+ ETEC仅导致中度腹泻。在7日龄感染的仔猪中，064株引起严重腹泻和死亡，020株在6头仔猪中有3头引起轻度腹泻，1头死亡，而08株未引起疾病。与这些感染相关的肠道病理变化轻微或不存在。用同源超免疫血清进行免疫荧光染色显示，这三株ETEC菌株均粘附于小肠上皮细胞的刷状缘。在所有感染仔猪中均观察到荧光菌，无论临床症状的严重程度如何，但定植的程度和范围随仔猪年龄和感染菌株而异。这可能解释了这三株菌临床反应的差异。
