Nagy B, Fekete P Z
Veterinary Medical Research Institute of the Hungarian Academy of Sciences, Budapest.
Vet Res. 1999 Mar-Jun;30(2-3):259-84.
Animal diseases due to enterotoxigenic Escherichia coli (ETEC) typically appear as severe watery diarrhoea during the first few days of life (also a few days after weaning in pigs). ETEC adhere to the small intestinal microvilli without inducing morphological lesions and produce enterotoxins acting locally on enterocytes. This action results in the hypersecretion (of water and electrolytes) and reduced absorption. Adhesins and toxins are the two prominent virulence attributes of ETEC and the level of knowledge of these factors determines the chances for successful prevention and therapy of the disease. For animal ETEC the most common adhesins are the fimbriae (pili) on the surface: F4(K88), F5(K99), F6(987P), F41, F42, F165, F17 and F18. Enterotoxins (extracellular proteins or peptides) of animal ETEC are classified as heat-labile (LT) and heat-stable (ST) enterotoxins with further subdivisions (LTh-I, LTp-I, LTIIa, LTIIb, STaH, STaP, STb) according to antigenic and biological differences. Fimbriae and LT enterotoxins are made up of large molecular weight proteins which facilitate their utilisation in vaccines and their detection using immunodiagnostic systems. The adhesive fimbriae and enterotoxins of animal ETEC are plasmid determined (except F41 and F17). Virulence gene probes (DNA hybridisation, PCR) are specific and sensitive diagnostic and epidemiologic tools for the detection of ETEC. Based on genetic typing, the ETEC, in spite of limited serogroups, seem to represent a population of E. coli with a diverse genetic background.
由产肠毒素大肠杆菌（ETEC）引起的动物疾病通常在出生后的头几天（猪断奶后的几天也会出现）表现为严重的水样腹泻。ETEC附着于小肠微绒毛，不引起形态学损伤，并产生局部作用于肠上皮细胞的肠毒素。这种作用导致（水和电解质的）过度分泌和吸收减少。黏附素和毒素是ETEC的两个主要毒力特性，对这些因素的了解程度决定了成功预防和治疗该疾病的可能性。对于动物ETEC，最常见的黏附素是表面的菌毛（纤毛）：F4（K88）、F5（K99）、F6（987P）、F41、F42、F165、F17和F18。动物ETEC的肠毒素（细胞外蛋白质或肽）根据抗原和生物学差异分为热敏性（LT）和耐热性（ST）肠毒素，并进一步细分（LTh-I、LTp-I、LTIIa、LTIIb、STaH、STaP、STb）。菌毛和LT肠毒素由大分子量蛋白质组成，便于在疫苗中使用以及利用免疫诊断系统进行检测。动物ETEC的黏附菌毛和肠毒素由质粒决定（F41和F17除外）。毒力基因探针（DNA杂交、PCR）是检测ETEC的特异性和灵敏的诊断及流行病学工具。基于基因分型，尽管血清群有限，但ETEC似乎代表了一群具有不同遗传背景的大肠杆菌。
