AUTHOR=Oliveira Lariane Teodoro , Medina-Alarcón Kaila Petronila , Singulani Junya de Lacorte , Fregonezi Nathália Ferreira , Pires Regina Helena , Arthur Rodrigo Alex , Fusco-Almeida Ana Marisa , Mendes Giannini Maria José Soares 

TITLE=Dynamics of Mono- and Dual-Species Biofilm Formation and Interactions Between Paracoccidioides brasiliensis and Candida albicans

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.551256

DOI=10.3389/fmicb.2020.551256

ISSN=1664-302X

ABSTRACT=<p>The oral cavity is a highly diverse microbial environment in which microorganisms interact with each other, growing as biofilms on biotic and abiotic surfaces. Understanding the interaction among oral microbiota counterparts is pivotal for clarifying the pathogenesis of oral diseases. <italic>Candida</italic> spp. is one of the most abundant fungi in the oral mycobiome with the ability to cause severe soft tissue lesions under certain conditions. <italic>Paracoccidioides</italic> spp., the causative agent of paracoccidioidomycosis, may also colonize the oral cavity leading to soft tissue damage. It was hypothesized that both fungi can interact with each other, increasing the growth of the biofilm and its virulence, which in turn can lead to a more aggressive infectivity. Therefore, this study aimed to evaluate the dynamics of mono- and dual-species biofilm growth of <italic>Paracoccidioides brasiliensis</italic> and <italic>Candida albicans</italic> and their infectivity using the <italic>Galleria mellonella</italic> model. Biomass and fungi metabolic activity were determined by the crystal violet and the tetrazolium salt reduction tests (XTT), respectively, and the colony-forming unit (CFU) was obtained by plating. Biofilm structure was characterized by both scanning electronic- and confocal laser scanning- microscopy techniques. Survival analysis of <italic>G. mellonella</italic> was evaluated to assess infectivity. Our results showed that dual-species biofilm with <italic>P. brasiliensis</italic> plus <italic>C. albicans</italic> presented a higher biomass, higher metabolic activity and CFU than their mono-species biofilms. Furthermore, <italic>G. mellonella</italic> larvae infected with <italic>P. brasiliensis</italic> plus <italic>C. albicans</italic> presented a decrease in the survival rate compared to those infected with <italic>P. brasiliensis</italic> or <italic>C. albicans</italic>, mainly in the form of biofilms. Our data indicate that <italic>P. brasiliensis</italic> and <italic>C. albicans</italic> co-existence is likely to occur on oral mucosal biofilms, as per <italic>in vitro</italic> and <italic>in vivo</italic> analysis. These data further widen the knowledge associated with the dynamics of fungal biofilm growth that can potentially lead to the discovery of new therapeutic strategies for these infections.</p>