Plasmid encoded enterotoxin (Pet) gene in enteroaggregative Escherichia coli isolated from sporadic diarrhea cases.

(2). The aggregative adherence of EAggEC was due to the presence of aggregative adherence fimbriae (AAF), AAF/ 1 and AAF/lI, whose expression lS positively controlled by the aggR gene (2)・ This aggR gene is present in many EAggECs, but some aggR-positive E. coli isolates have no AAFs (3,4). EAggEC was found to produce EAggEC heat-stable enterotoxin (EASTl encoded by astA, molecular weight 4.1 kDa) (2) and EAggEC plasmid encoded toxin (Pet encoded by pet, molecular weight 108 kDa) (5). Among them, EASTl is widely distributed in pathogenic E. coli regardless of the aggregative adherence phenotype (2). Nataro et al. reported