Yamamoto T, Wakisaka N, Sato F, Kato A
Departments of Infectious Diseases and Tropical Medicine, International Medical Center of Japan, Tokyo, Japan.
FEMS Microbiol Lett. 1997 Feb 1;147(1):89-95. doi: 10.1111/j.1574-6968.1997.tb10225.x.
The presence of the enteroaggregative Escherichia coli (EAggEC) heat-stable enterotoxin 1 (EAST1) gene was investigated in 15 strains each of EAggEC, enteropathogenic E. coli (EPEC), EPEC-related strains of non-EPEC serotypes, diffusely adhering E. coli (type 1 DAEC) that carries F1845 adhesive pili (or a related adhesin), and enteroinvasive E. coli (EIEC) by PCR and colony hybridization. The EAST1 gene or its homologue was present in 53.3% of EAggEC, 20% of EPEC, 13.3% of the EPEC-related strains, and 6.7% of type 1 DAEC, EIEC and E. coli unrelated with diarrhea had no gene with sequence similarity to the EAST1 gene. Comparison of the EAST1 gene sequences analyzed in this study as well as those reported previously showed that EAggEC (including strain O42, which was shown to be pathogenic in volunteer experiments), EPEC, type 1 DAEC, type 2 DAEC (which carries the 57-kDa outer membrane protein as an adhesin), and enterotoxigenic E. coli shared a common sequence. A variant type of the EAST1 gene sequence was present in the EAggEC strain 17-2 (initially characterized for the EAST1 gene) and in an EPEC-related strain of a non-EPEC serotype. These data suggest that the EAST1 gene or its variant is a virulence gene widely distributed among diarrhea-associated E. coli.
采用聚合酶链反应（PCR）和菌落杂交技术，对15株集聚性大肠埃希菌（EAggEC）、肠致病性大肠埃希菌（EPEC）、非EPEC血清型的EPEC相关菌株、携带F1845黏附菌毛（或相关黏附素）的弥漫性黏附大肠埃希菌（1型DAEC）以及肠侵袭性大肠埃希菌（EIEC）进行了肠集聚性大肠埃希菌热稳定肠毒素1（EAST1）基因检测。EAST1基因或其同源基因存在于53.3%的EAggEC、20%的EPEC、13.3%的EPEC相关菌株以及6.7%的1型DAEC中，EIEC和与腹泻无关的大肠埃希菌未发现与EAST1基因序列相似的基因。对本研究分析的EAST1基因序列以及先前报道的序列进行比较后发现，EAggEC（包括在志愿者实验中显示具有致病性的O42菌株）、EPEC、1型DAEC、2型DAEC（携带57 kDa外膜蛋白作为黏附素）和产肠毒素大肠埃希菌共有一个共同序列。在EAggEC菌株17 - 2（最初鉴定为EAST1基因）和非EPEC血清型的EPEC相关菌株中存在一种EAST1基因序列变异型。这些数据表明，EAST1基因或其变异体是一种在与腹泻相关的大肠埃希菌中广泛分布的毒力基因。
