Project

Finely tuned sensory systems enable bacteria to sense and respond to fluctuating environments, coordinating adaptive changes in metabolic pathways and physiological outputs. For pathogenic Leptospira, signaling pathways allow a timely expression of virulence factors during the successive steps of infection of a mammal host. As the bacteria is excreted by its host, signaling pathways enable switching the expression towards factors promoting survival in the environment. A unifying theme across bacterial species is that biofilm formation coincides with the synthesis of the cellular signaling molecule bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) and this feature seems to be conserved in Leptospira. Our current work shows that the c-di-GMP regulation pathway is a major regulatory network involved in biofilm formation, virulence and motility in the pathogen Leptospira interrogans. Biofilm production and virulence expression is quite variable across the leptospira genus (highly virulent species, low virulent species and saprophytes species showing increase biofilm production). We would like to explore how the c-di-GMP metabolism, and the many genes associated with its synthesis, and degradation have evolved across the leptospira genus. We believe that understanding the evolutionary relationship of the c-di-GMP metabolism genes in the Leptospira genus would help us to understand the contribution of this second messenger to pathogenesis and biofilm formation in the Leptospira genus