In. Okeke et al., Heterogeneous virulence of enteroaggregative Escherichia coli strains isolated from children in southwest Nigeria, J INFEC DIS, 181(1), 2000, pp. 252-260
Enteroaggregative Escherichia coli (EAEC) has been implicated in acute and
persistent diarrhea, and most strains harbor a member of a partially-conser
ved plasmid family (called pAA). We studied EAEC isolated from Nigerian chi
ldren aged <5 years to elucidate the roles of plasmid and chromosomal EAEC
loci. We tested a total of 131 EAEC strains isolated from acute diarrhea ca
se patients and control subjects for hybridization with 8 pAA plasmid-deriv
ed and 2 chromosomal gene probes, for several in vitro phenotypes and for r
esistance to antimicrobial agents. Using by multiple logistic regression, w
e found genes encoding the AAF/II fimbriae to be strongly associated with d
iarrhea in this population. EAEC strains appear to be of heterogeneous viru
lence, and data suggest that AAF/II may be a marker for pathogenic strains.