Biofilms are microbial communities in which cells are embedded in a self-produced matrix of extracellular polymeric substances. This life style is predominant in environmental and pathogenic bacteria, once it provides opportunities for social interaction and protection against external stress factors. Biofilm formation has an importance in public heath since some chronic infections normally associated to bacterial biofilms are difficult to eradicate due to the increase in resistance against antimicrobial agents and the host defenses. The aim of this project is to unveil the genetic basis for biofilm formation in Chromobacterium violaceum and to evaluate which of the genes involved in this process can contribute to the virulence of this opportunistic bacterial pathogen. Genetic determinants of biofilm development will be investigated through the screening of a transposon mutant library in C. violaceum which will be performed using a microtiter plate (solid surface-associated biofilms) and glass tubes (pellicle, 'floating' biofilm). The mutant strains showing alteration in the biofilm formation will be analyzed to identify the transposon insertion site and to characterize the biofilm structure under the microscope. Mutant genes in the regulatory or signaling pathways will be selected for characterization in animal model infection to understand the relationship between biofilm and virulence. Data obtained in this project will contribute to unveil the genetic mechanisms important in the biofilm formation in C. violaceum and to elucidate the relationship between the biofilm and the infection caused by this bacterium.
News published in Agência FAPESP Newsletter about the scholarship: