Enteroaggregative Escherichia coli virulence markers: positive association with distinct clinical characteristics and segregation into 3 enteropathogenic E. coli serogroups.

Background: Enteroaggregative Escherichia coli (EAEC) are a heterogeneous category of emerging pathogens associated with acute and persistent diarrhea.

Methods: We performed a case-control study to evaluate the association of EAEC strains and their virulence markers with infantile diarrhea in Brasilia, Brazil.

Results: Of the EAEC markers that were tested, only EAEC heat-stable toxin (EAST1), protein involved in colonization (Pic), and the CVD432 sequence showed positive correlation with diarrhea; however, these virulence traits presented associations with distinct clinical characteristics.

Virulence markers of enteroaggregative Escherichia coli isolated from children and adults with diarrhea in Brasília, Brazil.

Escherichia coli strains isolated from sporadic cases of acute diarrhea in children and adults and from children without diarrhea were investigated for the presence of the pAA plasmid. Strains harboring the pAA plasmid were isolated at similar frequencies from children with (19.6%) and without (10.