Influence of type 2 quorum sensing in a multi species biofilm model

• Grant number: 23/03868-3
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: September 01, 2023
• End date: December 31, 2023
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Thiago Rojas Converso
• Grantee: Giulia Vicente Destro
• Supervisor: Fernanda Cristina Petersen
• Host Institution: Universidade São Francisco (USF). Campus Bragança Paulista. Bragança Paulista , SP, Brazil
• Institution abroad: University of Oslo (UiO), Norway
• Associated to the scholarship: 21/13787-5 - The polysaccharide capsule in biofilm formation by Streptococcus pneumoniae, BP.IC

Abstract

Streptococcus pneumoniae is a pathogen commonly associated with morbidity and mortality in children and the elderly, especially in less developed countries, causing about one million deaths annually. During its colonization process, which usually occurs in the nasopharynx, there is the possibility of invading sterile sites and causing disease. Colonization is associated with biofilm formation, a virulence mechanism that helps the bacteria to survive in the host, resist antibacterials, and serve as a reservoir of pathogens that can disseminate following biofilm dispersion. For biofilm formation, communication via quorum sensing is necessary, which from type 2 self-inducing molecules enables intra and interspecies communication. So far, most knowledge on the type 2 quorum sensing are derived from studies analyzing the impact of this system on single or dual-species biofilms. While such studies have provided critical mechanistic insights, there is still a lack of understanding on the impact of AI-2 in complex microbial communities as those found in humans, including the nasopharynx. For the current application we aim to investigate the potential of the type 2 quorum sensing system to impact microbial communities using a human ex-vivo microbiome model of biofilm formation established in Dr Petersen's laboratory. Samples from nasopharynx aspirates will be used as inoculum. We will focus on changes that affect major human pathogens found in the healthy microbiome, including Streptococcus pneumoniae, Staphylococcus aureus and epidermidis, and Klebsiella pneumoniae. We expect that the results will provide relevant information on the potential of the type 2 system to modulate the composition of complex microbial communities originating from the human nasopharynx, and thus help in designing novel strategies to fight infections. (AU)