Genotypic and phenotypic characterization of enteroaggregative (EAEC) isolates from diarrheic children: An unresolved diagnostic paradigm exists.

OBJECTIVES

The enteroaggregative (EAEC) has been one of the most intriguing emerging bacterial pathogens in children that occur both in developing countries and the industrial world. Although various phenotypic and genotypic based protocols have been suggested for diagnosis of EAEC, they are not conclusive or practical to be used in most clinical laboratories.

MATERIALS AND METHODS

In this study, we analyzed and compared 36 typical EAEC strains (-positive) by various genotypic and phenotypic methods.

RESULTS

Briefly, pCVD432 was detected in all of isolates along with aggR, then it was followed by other virulence genes including , and genes in 32 (88.8%), 21 (58.3%), 9 (25%), and 2 (5.5%) isolates, respectively. Biofilm was formed by 34 (94.4%) isolates, while only 26 (72.2%) isolates showed an aggregative adherence pattern to HEp-2 cells.

CONCLUSION

The genetic and phenotypic features of EAEC were highly inconsistent, which may have considerable diagnostic implications. The variations in the virulence genes, phenotypic characteristics, and genetic profiles among the EAEC isolates again emphasized the genetic heterogeneity of this emerging pathotype. Biofilm formation may be an important phenotypic virulence property of this pathotype, especially in strains with the -pCVD432- profile.