The activity of bacterial peptidylarginine deiminase is important during formation of dual-species biofilm by periodontal pathogen Porphyromonas gingivalis and opportunistic fungus Candida albicans

• Published in: Pathogens and disease Vol. 76; no. 4
• Main Authors: Karkowska-Kuleta, Justyna, Bartnicka, Dominika, Zawrotniak, Marcin, Zielinska, Gabriela, Kierońska, Anna, Bochenska, Oliwia, Ciaston, Izabela, Koziel, Joanna, Potempa, Jan, Baster, Zbigniew, Rajfur, Zenon, Rapala-Kozik, Maria
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01-06-2018
• Subjects: Aerobic conditions; Anaerobes; Arginine; Bacteria; Bacterial Adhesion; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biofilms; Biofilms - growth & development; Candida albicans; Candida albicans - pathogenicity; Candida albicans - physiology; Citrulline; Colonization; Fungi; Gene Expression; Gum disease; Humans; Hypoxia; Microbial Interactions; Microorganisms; Opportunist infection; Oral cavity; Pathogens; Periodontitis; Porphyromonas gingivalis; Porphyromonas gingivalis - enzymology; Porphyromonas gingivalis - genetics; Porphyromonas gingivalis - growth & development; Porphyromonas gingivalis - pathogenicity; Protein-arginine deiminase; Protein-Arginine Deiminases - genetics; Protein-Arginine Deiminases - metabolism; Proteins; Spectrometry; Viability; Virulence; Virulence factors; Virulence Factors - genetics; Virulence Factors - metabolism; cytokine; peptidylarginine deiminase; enolase; periodontitis; citrullination; mixed biofilms; macrophage
• ISSN: 2049-632X; 2049-632X
• DOI: 10.1093/femspd/fty033

Abstract
Porphyromonas gingivalis, an anaerobic Gram-negative bacterium critically involved in the development of human periodontitis, belongs to the late colonizers of the oral cavity. The success of this pathogen in the host colonization and infection results from the presence of several virulence factors, including extracellular peptidylarginine deiminase (PPAD), an enzyme that converts protein arginine residues to citrullines. A common opportunistic fungal pathogen of humans, Candida albicans, is also frequently identified among microorganisms that reside at subgingival sites. The aim of the current work was to verify if protein citrullination can influence the formation of mixed biofilms by both microorganisms under hypoxic and normoxic conditions. Quantitative estimations of the bacterial adhesion to fungal cells demonstrated the importance of PPAD activity in this process, since the level of binding of P. gingivalis mutant strain deprived of PPAD was significantly lower than that observed for the wild-type strain. These results were consistent with mass spectrometric detection of the citrullination of selected surface-exposed C. albicans proteins. Furthermore, a viability of P. gingivalis cells under normoxia increased in the presence of fungal biofilm compared with the bacteria that formed single-species biofilm. These findings suggest a possible protection of these strict anaerobes under unfavorable aerobic conditions by C. albicans during mixed biofilm formation.
Porphyromonas gingivalis exploits protein citrullination during formation of mixed-species biofilms with Candida albicans.