Nov 17, 1998

Two enteropathogenic Escherichia coli type III secreted proteins, EspA and EspB, are virulence factors

The Journal of Experimental Medicine
Akio AbeB Brett Finlay

Abstract

Enteropathogenic Escherichia coli (EPEC) belongs to a family of related bacterial pathogens, including enterohemorrhagic Escherichia coli (EHEC) O157:H7 and other human and animal diarrheagenic pathogens that form attaching and effacing (A/E) lesions on host epithelial surfaces. Bacterial secreted Esp proteins and a type III secretion system are conserved among these pathogens and trigger host cell signal transduction pathways and cytoskeletal rearrangements, and mediate intimate bacterial adherence to epithelial cell surfaces in vitro. However, their role in pathogenesis is still unclear. To investigate the role of Esp proteins in disease, mutations in espA and espB were constructed in rabbit EPEC serotype O103 and infection characteristics were compared to that of the wild-type strain using histology, scanning and transmission electron microscopy, and confocal laser scanning microscopy in a weaned rabbit infection model. The virulence of EspA and EspB mutant strains was severely attenuated. Additionally, neither mutant strain formed A/E lesions, nor did either one cause cytoskeletal actin rearrangements beneath the attached bacteria in the rabbit intestine. Collectively, this study shows for the first time that the type III s...Continue Reading

Mentioned in this Paper

Pathogenic Aspects
Bacterial Proteins
Pathogenesis
Histology Procedure
Structure of Aggregated Lymphoid Follicle of Small Intestine
Pathogenicity
Isoactin
Actins
Signal Transduction Pathways
Outer Membrane Lipoproteins, Bacterial

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