Prevalence, sequence diversity, and amplification of an IS-associated enterotoxin gene, <i>astA</i>, in <i>Escherichia coli</i>.

ABSTRACT:

Introduction

Enteroaggregative Escherichia coli heat-stable enterotoxin 1 (EAST1) encoded by the astA gene was first identified in an enteroaggregative E. coli strain isolated from a patient with persistent diarrhea. While astA-positive strains sometimes cause large food poisoning outbreaks, the significance of EAST1 as a virulence factor remains unclear. Additionally, although the prototype and seven variants of the astA gene have been identified, the biological significance of these genetic variations remains undefined. This study aimed to elucidate the characteristics of the A gene by investigating its distribution and sequence diversity within the evolutionary lineages of Escherichia coli.

Methods

We conducted PCR screening for the astA gene i

SUBMITTER: Ooka T 

PROVIDER: S-EPMC12585946 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature