Novel molecular mechanisms putatively involved with bacterial resistance to antibiotics

• Grant number: 21/11062-3
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2022
• End date: January 31, 2024
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Regina Lúcia Baldini
• Grantee: Regina Lúcia Baldini
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The emergence and spread of antibiotic multiresistant bacteria is a world health concern, as the infections are becoming more difficult to fight, particularly in hospital settings. Pseudomonas aeruginosa is an opportunistic pathogen common in nosocomial infections, it is intrinsicaly resistant to many drugs and has high adaptative capabilities. The study of this pathogen's physiology, especially of mechanisms involved in growth in the presence of antimicrobial compounds, may result in the discovery of novel targets for the development of therapeutic innovations. The second messenger c-di-GMP is crucial for the bacterial lifestyle decision between sessile and motile forms of growth. Proteins required for the synthesis and breakdown of c-di-GMP, as well as its sensors, might represent such potential therapeutic targets, as the growth in biofilms, stimulated by high concentrations of this nucleotide, complicates the treatment of chronic infections. This project aims to study uncharacterized proteins from c-di-GMP signaling pathways. Our previous work has shown that the diguanilate cyclase DgcP localizes at the cell poles and interacts with the type four pilus (T4P) scaffold protein FimV. The T4P is a virulence factor important for biofilm formation and it is a mechanosensor that activates pathogenicity-related genes, such as those involved in quorum sensing. In this present work, we intend to deepen the knowledge on DgcP, which presents a large unstructured region at its N-terminal with no described function. DgcP also seems to interact with an ECF sigma factor, PA14_46810, which regulon includes genes for the synthesis of nitric oxide. NO is an exogenous signal for biofilm dispersion, and here we will investigate whether its intracellular production in pathways involved with c-di-GMP have a role in biofilm dispersion events. As a third aim, we will characterize the protein PA14_04420, with a domain for c-di-GMP synthesis or binding and which our previous studies pointed to its interaction with proteins involved in cell growth and division. Moreover, a PA14_04420 mutant strain presents a growth pattern different from the wild type when the medium is supplemented with subinhibitory antibiotic concentrations. To reach our goals, we will use genetic, biochemistry and molecular biology approaches, with strategies already in use by our own group, as well as taking advantage of collaborations with distinguished local and international research groups. We expect to uncover new molecular mechanisms used by P. aeruginosa that may become a starting point for the chase of much needed novel strategies to overcome infections. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BASTOS, RAFAEL WESLEY; AKIYAMA, DANIEL; DOS REIS, THAILA FERNANDA; COLABARDINI, ANA CRISTINA; LUPERINI, RAFAEL SANCHEZ; DE CASTRO, PATRICIA ALVES; BALDINI, REGINA LUCIA; FILL, TAICIA; GOLDMAN, GUSTAVO H.. Secondary Metabolites Produced during Aspergillus fumigatus and Pseudomonas aeruginosa Biofilm Formation. MBIO, v. 13, n. 4, p. 17-pg., 2022-07-20. (17/07536-4, 21/07038-0, 21/11062-3, 17/19821-5, 16/07870-9, 21/00728-0, 16/12948-7)