Role of glucosyltransferase R in biofilm interactions between Streptococcus oralis and Candida albicans

Author(s)

Silva Souza, Joao Gabriel ^{[1, 2]} ; Bertolini, Martinna ^[1] ; Thompson, Angela ^[1] ; Mansfield, Jillian M. ^[3] ; Grassmann, Andre Alex ^{[4, 5, 6]} ; Maas, Kendra ^[7] ; Caimano, Melissa J. ^{[4, 5, 6]} ; Ricardo Barao, Valentim Adelino ^[2] ; Vickerman, M. Margaret ^[3] ; Dongari-Bagtzoglou, Anna ^[1]

Affiliation

^[1] Univ Connecticut, Sch Dent Med, Dept Oral Hlth & Diagnost Sci, Farmington, CT 06032 - USA

^[2] Univ Estadual Campinas, Piracicaba Dent Sch, Dept Prosthodont & Periodontol, UNICAMP, Sao Paulo, SP - Brazil

^[3] Univ Buffalo, Sch Dent Med, Dept Oral Biol, Buffalo, NY 14260 - USA

^[4] Univ Connecticut, Hlth Ctr, Dept Med, Farmington, CT - USA

^[5] Univ Connecticut, Hlth Ctr, Dept Pediat, Farmington, CT - USA

^[6] Univ Connecticut, Hlth Ctr, Dept Mol Biol, Farmington, CT - USA

^[7] Univ Connecticut, Microbial Anal Resources & Serv Core, Storrs, CT - USA

• Document type: Journal article
• Source: ISME Journal; v. 14, n. 5 FEB 2020.
• Web of Science Citations: 9

Abstract

Streptococcal glucosyltransferases (Gtf) synthesize alpha-glucan exopolymers which contribute to biofilm matrix. Streptococcus oralis interacts with the opportunistic pathogen Candida albicans to form hypervirulent biofilms. S. oralis 34 has a single gtf gene (gtfR). However, the role of gtfR in single and mixed species biofilms with C. albicans has never been examined. A gtfR deletion mutant, purified GtfR, and recombinant GtfR glucan-binding domain were tested in single and mixed biofilms on different substrata in vitro. A mouse oral infection model was also used. We found that in single species biofilms growing with sucrose on abiotic surfaces S. oralis gtfR increased biofilm matrix, but not bacterial biomass. In biofilms with C. albicans, S. oralis encoding gtfR showed increased bacterial biomass on all surfaces. C. albicans had a positive effect on alpha-glucan synthesis, and alpha-glucans increased C. albicans accretion on abiotic surfaces. In single and mixed infection of mice receiving sucrose S. oralis gtfR enhanced mucosal burdens. However, sucrose had a negative impact on C. albicans burdens and reduced S. oralis burdens in co-infected mice. Our data provide new insights on the GtfR-mediated interactions between the two organisms and the influence of biofilm substratum and the mucosal environment on these interactions. (AU)

• FAPESP's process: 17/21289-0 - Streptococcus-Candida interactions in biofilms formed on titanium surface
• Grantee: João Gabriel Silva Souza
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate