BB3576 diguanilate cyclase protein regulates motility and biofilm in Bordetella bronchiseptica

SISTI, FEDERICO; FERNANDEZ, JULIETA

Congreso; 3. XLVIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012

Cyclic diguanylate (c-di-GMP) is a ubiquitous second messenger that regulates diverse cellular functions, including motility, biofilm formation, and virulence in bacteria. Components of this regulatory network include GGDEF domain-containing proteins that synthesis c-di-GMP. In a previous work we demonstrated that heterologous expression of a Pseudomonas aeruginosa GGDEF protein modifies biofilm formation capacity and motility in B. bronchiseptica (Bb), a pathogenic bacterium that causes respiratory infections in a wide variety of host.In this work, we analyzed the expression of BB3576, a putative GGDEF protein of B. bronchiseptica. To this end, bb3576 gene from Bb was amplified and cloned in the replicative plasmid pBBMCR5 under a constitutive promoter and transformed in Bb. Biofilm formation and motility were evaluated in the recombinant bacteria to detect possible changes in c-di-GMP concentrations. As found in other organisms that contain high levels of c-di-GMP, we observed that Bb was able to form biofilm and reduce its motility only in the case bacteria express GGDEF domain-containing protein. Interestingly, high bb3576 mRNA expression levels were detected by real time PCR in avirulent phase, when motility is present. These results demonstrate the presence of a functional GGDEF protein in Bb and suggest a putative motility regulation function for BB3576.