Isolation and characterization of Streptococcus spp. from patients with bacterial endocarditis

• Grant number: 23/02087-8
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2023
• End date: December 31, 2025
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Lívia Araújo Alves
• Grantee: Lívia Araújo Alves
• Host Institution: Pró-Reitoria de Pós-Graduação e Pesquisa. Universidade Cruzeiro do Sul (UNICSUL). São Paulo , SP, Brazil
• Associated scholarship(s): 23/10599-9 - Evaluation of antimicrobial susceptibility of Streptococcus spp. isolated from patients with bacterial endocarditis, BP.TT; 23/10623-7 - Identification of species of Streptococcus spp. isolated from patients with bacterial endocarditis by PCR, BP.TT

Abstract

Infective endocarditis (IE) is a microbial infection of the cardiac endothelium, which microorganisms invade the circulation and can colonize the surfaces lining the heart (endocardium), producing inflammation and damage. There is a high prevalence of oral bacteria in endocarditis lesions due to the transfer of bacteria from the oral cavity to the bloodstream, allowing bacterial adherence to endocardial surfaces. The Streptococcus spp. oral agents are among the most frequent agents in IE (~50% of cases). This project aims to isolate and characterize strains of Streptococcus spp. mouths of patients with bacterial endocarditis. For this, blood samples and oral samples will be collected from patients diagnosed with IE treated at Instituto Dante Pazzanese de Cardiologia (São Paulo - SP, Brazil) for isolation of Streptococcus spp. oral. The isolated strains will be taxonomically characterized by PCR using group-specific and species-specific primers and the DNA extracted from the samples submitted to 16S RNA gene sequencing. Species clones present in blood samples will be compared with clones of the same species isolated from the saliva of patients with bacterial endocarditis by the AP-PCR technique (Arbitrarily Primed-PCR). Also, the susceptibility of Streptococcus spp. isolated to antibiotics commonly associated with bacterial resistance in these species. Mature biofilms (18h) of Streptococcus spp. isolates will be formed in the presence of human saliva and serum in microtiter plates. The results of this study should generate important information about the mechanisms of virulence of these species from the isolation and characterization of strains of Streptococcus spp. Oral infections isolated from patients with endocarditis. Furthermore, this study will help to understand whether clones of species isolated from sites in the oral cavity are the same clones isolated from the blood of patients with bacterial endocarditis. (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)

FRANCO, EDUARDO M.; ALVES, LIVIA A.; NAVEED, HASSAN; FREITAS, VICTOR A. A.; BASTOS, DEBORA C.; MATTOS-GRANER, RENATA O.. Amyloid Fibrils Produced by Streptococcus sanguinis Contribute to Biofilm Formation and Immune Evasion. INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES, v. 24, n. 21, p. 22-pg., 2023-11-01. (17/19899-4, 18/02054-4, 18/12248-0, 23/02087-8, 21/13074-9)

FRANCO, EDUARDO M.; ALVES, LIVIA A.; CAMARGO, ISABELA; SALVATIERRA, GEOVANNY C.; GARCIA, MAIRA TERRA; CHEN, TSUTE; JUNQUEIRA, JULIANA C.; BASTOS, DEBORA C.; MATTOS-GRANER, RENATA O.. Contribution of a LysM domain-containing protein regulated by VicRK to Streptococcus sanguinis virulence. VIRULENCE, v. 16, n. 1, p. 19-pg., 2025-12-31. (21/13074-9, 23/02087-8, 23/14816-4, 17/23183-4, 18/02054-4, 18/12248-0)