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Aggregative
Escherichia coli (EAEC) - the new group of diarrheagenic
strains E. coli
Abstract:
Enteroaggregative
E. coli strains (EAEC) are the most recently described
category of diarrheagenic E. coli defined by its
aggregative or "stacked-brick" pattern of adherence to cultured
human
epithelial cells. EAEC has been associated with persistent
diarrhea among infants and small children. Most EAEC strains
harbour a pAA virulence plasmid which is required for
expression of aggregative adherence fimbriae AAF/I and AAF/II.
That plasmid also mediates mannose resistant hemagglutinin
production and bacterial clumpp formation. EAEC strains comprising
a diverse range of
serotypes that possess a variety of putative virulence factors,
the heat-stable enterotoxin EAST 1. cytotoxin Pet, hemolysin, and
various types of fimbriae among them. The pathogenic
mechanisms of EAEC
infections are not fully elucidated so clinical significance of
enteroaggregative E. coli strains is still poorly
understood.
1. Introduction.
2. Characterization of EAEC strains. 3. Virulence
plasmid pAA. 3.1. Aggregative fimbriae AAF. 4. Toxins of
EAEC. 4.1. Heat-labile enterotoxin of EAEC - EAST 1. 4.2. Plasmid
-
encoded toxin - Pet. 4.2.1. Autotransporter secreted proteins
of Gram-negative bacteria. 4.3. Mucinase Pic. 4.4. Other
toxins of EAEC. 5. Flagellin of aggregative E. coli.
6. Yersiniobactin. 7. Invasiveness of enteroaggregative
strains of E. coli. 8. Patomechanism of infection
of EAEC. 9. Summary |
