Maria Hedberg
Umeå University, Sweden
Title: Prevotella jejuni- Anaerobic Gram-Negative Bacterium Associated to Coeliac Disease
Biography
Biography: Maria Hedberg
Abstract
Prevotella sp. are strictly anaerobic Gram-negative rods constituting a substantial part of the normal human micro-flora. About 50 species have been described at present, of which a great part are of oral and upper airways origin, while others have been isolated from the gastrointestinal and urogenital tract, and some species origin from animal sources. Prevotella sp. often occur in opportunistic infections and dysbiosis-associated diseases, but may also be involved in severe infections and various virulence factors have been demonstrated. The new species Prevotella jejuni was discovered from a biopsy taken from the small intestine of a child with coeliac disease. Three different strains of the species were isolated and phylogenetic analysis based on 16S rRNA gene sequence analysis revealed a close relationship between them. When grown on blood agar plates the three P. jejuni strains were pigmented and weakly or strongly hemolytic. They were able to form saccharolytic and proteolytic enzymes and by flow cytometry they were shown to bind to human intestinal carcinoma cell-lines in suspension. Scanning electron microscopy (SEM) and transmission electron microcopy (TEM) displayed formation of aggregates in which tube-like structures were connecting between individual cells and outer membrane vesicles (OMVs) could also be observed. Prevotella sp. are in general considered to be susceptible to bile but in the case of P. jejuni the growth was stimulated by sub-inhibitory concentrations of bile, suggesting an adaption to the hostile milieu of the small intestine. The strains have been subjected to whole genome sequencing (WGS) using 454-pyro-sequencing technology.