Candida albicans cell wall integrity transcription factors regulate polymicrobial biofilm formation with Streptococcus gordonii

Jennifer Chinnici; Lisa Yerke; Charlene Tsou; Sujay Busarajan; Ryan Mancuso; Nishanth D Sadhak; Jaewon Kim; Abhiram Maddi

doi:10.7717/peerj.7870

Candida albicans cell wall integrity transcription factors regulate polymicrobial biofilm formation with Streptococcus gordonii

PeerJ. 2019 Oct 11:7:e7870. doi: 10.7717/peerj.7870. eCollection 2019.

Authors

Jennifer Chinnici¹, Lisa Yerke¹, Charlene Tsou¹, Sujay Busarajan¹, Ryan Mancuso¹, Nishanth D Sadhak¹, Jaewon Kim¹, Abhiram Maddi¹

Affiliation

¹ Departments of Periodontics & Endodontics and Oral Biology, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY, United States of America.

Abstract

Polymicrobial biofilms play important roles in oral and systemic infections. The oral plaque bacterium Streptococcus gordonii is known to attach to the hyphal cell wall of the fungus Candida albicans to form corn-cob like structures in biofilms. However, the role of C. albicans in formation of polymicrobial biofilms is not completely understood. The objective of this study was to determine the role of C. albicans transcription factors in regulation of polymicrobial biofilms and antibiotic tolerance of S. gordonii. The proteins secreted by C. albicans and S. gordonii in mixed planktonic cultures were determined using mass spectrometry. Antibiotic tolerance of S. gordonii to ampicillin and erythromycin was determined in mixed cultures and mixed biofilms with C. albicans. Additionally, biofilm formation of S. gordonii with C. albicans knock-out mutants of 45 transcription factors that affect cell wall integrity, filamentous growth and biofilm formation was determined. Furthermore, these mutants were also screened for antibiotic tolerance in mixed biofilms with S. gordonii. Analysis of secreted proteomes resulted in the identification of proteins being secreted exclusively in mixed cultures. Antibiotic testing showed that S. gordonii had significantly increased survival in mixed planktonic cultures with antibiotics as compared to single cultures. C. albicans mutants of transcription factors Sfl2, Brg1, Leu3, Cas5, Cta4, Tec1, Tup1, Rim101 and Efg1 were significantly affected in mixed biofilm formation. Also mixed biofilms of S. gordonii with mutants of C. albicans transcription factors, Tec1 and Sfl2, had significantly reduced antibiotic tolerance as compared to control cultures. Our data indicates that C. albicans may have an important role in mixed biofilm formation as well as antibiotic tolerance of S. gordonii in polymicrobial biofilms. C. albicans may play a facilitating role than being just an innocent bystander in oral biofilms and infections.

Keywords: Ampicillin resistance; Antibiotic tolerance; Candida albicans; Interkingdom interactions; Phenotypic switch; Polymicrobial biofilms; Streptococcus gordonii.

Associated data

figshare/10.6084/m9.figshare.9862856.v1

Grants and funding

This work was supported by State University of New York Start up funding. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.