| Congresso Brasileiro de Microbiologia 2023 | Resumo: 882-1 | ||||
Resumo:Leptospirosis is a worldwide spread zoonosis caused by pathogenic bacteria of the genus Leptospira. The pathogenic leptospires species survive a variety of adverse conditions in the external environment and inside the host, producing several mechanisms for their survival. One of these mechanisms is the production of bis-(3′-5′) cyclic dimeric guanosine monophosphate (c-di-GMP), a cellular second messenger that controls several behaviors in bacteria, including the regulation of production of virulence factors. Understanding the production of proteins involved in c-di-GMP synthesis, degradation, and signaling by leptospires is critical to understanding how the bacterium survives. Unfortunately, there are few studies on c-di-GMP production and its influence on bacterial virulence. The LIC_11128 protein is a diguanylate cyclase, responsible for the synthesis of c-di-GMP in L. interrogans serovar Copenhageni Fiocruz strain L1-130. Previous studies from our group have shown, in vitro, that rLIC_11128 is a dimeric protein, in which one of its monomers binds to 2,5-diketopiperazine Brevianamide F, a secondary metabolite produced by a few fungi and bacteria. To evaluate if L. interrogans was affected by the presence of Brevianamide F, we added 100 µM and 300 µM of Brevianamide F to the culture and observed that there was a decrease in the population of leptospires treated compared to the control group (p<0.05). We evaluated if L. biflexa serovar Patoc 1 strain Paris (non-pathogenic bacterium) was affected by Brevianamide F and the results were similar to those observed with L. interrogans. To evaluate whether Brevianamide F affected the growth of other bacteria, we performed the same experiment with Chromobacterium violaceum, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Unlike Leptospira, these bacteria showed an increase in their growth when compared to the control group (p<0.05). Finally, to evaluate the diguanylate cyclase activity of the enzyme in the presence of Brevianamide F by ion exchange chromatography, we incubated 600nM of the rLIC_11128 with 1mM guanosine-5'-triphosphate (GTP) and 50µM Brevianamide F. The results showed that the enzyme has diguanylate cyclase activity independent of the presence of Brevianamide F. Our results show that Brevianamide F affects the growth of bacteria of the genus Leptospira, unlike other genera of bacteria. Furthermore, the diguanylate cyclase activity of rLIC_11128 is independent of the presence of Brevianamide F. Palavras-chave: 2,5-diketopiperazine, Brevianamide F, c-di-GMP signaling, leptospirosis, LIC_11128 Agência de fomento:CAPES e FAPESP | |||||