Role of bacteria cell surface structures in Xanthomonas axonopodi pv citri biofilm formation,

MALAMUD, FLORENCIA; ROESCHLIN, ROXANA; ENRIQUE, RAMÓN; SICILIANO, FLORENCIA; MARANO, MARIA ROSA; VOJNOV, ADRIÁN

Rosario

Congreso; V Congreso Argentino de Microbiología General SAMIGE 2008; 2008

Sociedad Argentina de Microbiología General

A biofilm is a community of bacteria embedded in an extracellular matrix that can be attached to a surface. This structure is believed to provide protection to bacteria from environmental aggressiveness. Previous works in other microorganisms have shown that external bacterial proteins are implicated in the first step of biofilm formation. Xanthomonas axonopodis pv. citri (Xac) is the causative agent of citrus canker. Previous work from our laboratory demostrated that this bacterium is able to produce biofilm both in vitro and in vivo. To evaluate the participation of different external proteins structures in the adhesion step we generated three diferent mutans: Xac fliC (flagelin gene), Xac flgE (hook gene) mutans, both involved in flagella structure, and Xac fhaB encoding non fimbrial adhesin. In cuantitative violet crystal experiments these mutants showed differences in adhesion compared to Xac wild type. We also used confocal laser scanning microscope to analyze biofilm formation for these mutants. Differences were observed in the biofilm architecture between wild type and mutan strains. Swimming and swarming motility experiments also showed a marked alterations. In addition, we found differential beahavior and symptoms development in host plants infection experiments.