Development of new diagnostic options for Enteroaggregative Escherichia coli as an important diarrheal pathogen

Abstract

Diarrhea is an important disease burden worldwide. It causes considerable childhood mortality in the developing world and is associated with morbidity and substantial health care costs also in industrialized countries. Enteroaggregative Escherichia coli (EAEC) are a major cause of acute diarrhea in developing and industrialized regions. So far, the gold standard for EAEC identification is the recognition of the so-called "stacked-brick" adherence phenotype on HEp-2 cells. Molecular techniques have been developed to detect pathogenic EAEC strains, and various gene targets have been used. Nevertheless, no consensus has been reached so far, on which EAEC marker genes unambiguously correlate with pathogenicity. Thus, our aim is to increase the diagnostic sensitivity of EAEC. Whole genome sequencing of larger sets of well-defined clinical isolates and consecutive comparative genomic studies will identify targets that can be used to improve EAEC detection and risk assessment, e.g. translating into the development of a biosensor for sensitive EAEC detection in urine, blood or stool. As the individual contribution of EAEC to the development of diarrhea, especially in mixed infections, is often unclear, intestinal microbiome analyses of patients will shed further light on host microbiome factors associated with EAEC-associated diarrhea and thus facilitate EAEC typing and diagnosis. (AU)