Analysis of interaction between dispersin and plasminogen in the enteroaggregative Escherichia coli (EAEC) pathogenesis

Abstract

Escherichia coli is a gram-negative bacillus, facultative, which can as belong to microbiota, playing an important role in intestinal regulation, as cause disease. Enteroagreggative Escherichia coli (EAEC) is a pathotype frequently associated to traveler´s and persistent diarrheas. O104:H4 is a serogroup of EAEC which caused an outbreak in Europe, mainly affecting German. This pathotype houses several virulence factors and one of them is the dispersin, a protein codificated by app gene and positively charged. Dispersin coats the bacteria LPS and it can repel the AAF fimbria, which also has positive charge, preventing the binding between LPS and AAF and increasing bacteria dispersion due fimbriae projection. Preliminary assays made in our laboratory showed that recombinant dispersin, obtained from 042 EAEC strain, interacts more significantly with plasminogen than others cellular components, in dose-dependent mode. Plasmin is the active form of plasminogen and it can degrade cellular matrix components by different ways. Some bacteria can activate plasminogen which can facilitate their penetration in the tissues after degradation of cellular matrix components. Therefore, our aim is analyzed the role of interaction between dispersin and plasminogen in the pathogenesis of EAEC 042 by comparative assays between the wild type and aap gene mutant bacterium, obtained by non-polar mutation strategy employing suicide vector pJP5603, as well as by assays of plasmin activation and fibrinogen cleavage in presence of purified protein. (AU)