Soluble factors from biofilm of Candida albicans and Staphylococcus aureus promote cell death and inflammatory response

Abstract

BackgroundThe objective of this study was to better understand the effects of soluble factors from biofilm of single- and mixed-species Candida albicans (C. albicans) and methicillin-sensitive Staphylococcus aureus (MSSA) cultures after 36 h in culture on keratinocytes (NOK-si and HaCaT) and macrophages (J774A.1). Soluble factors from biofilms of C. albicans and MSSA were collected and incubated with keratinocytes and macrophages, which were subsequently evaluated by cell viability assays (MTT). Lactate dehydrogenase (LDH) enzyme release was measured to assess cell membrane damage to keratinocytes. Cells were analysed by brightfield microscopy after 2 and 24 h of exposure to the soluble factors from biofilm. Cell death was detected by labelling apoptotic cells with annexin V and necrotic cells with propidium iodide (PI) and was visualized via fluorescence microscopy. Soluble factors from biofilm were incubated with J774A.1 cells for 24 h; the subsequent production of NO and the cytokines IL-6 and TNF-α was measured by ELISA.ResultsThe cell viability assays showed that the soluble factors of single-species C. albicans cultures were as toxic as the soluble factors from biofilm of mixed cultures, whereas the soluble factors of MSSA cultures were less toxic than those of C. albicans or mixed cultures. The soluble factors from biofilm of mixed cultures were the most toxic to the NOK-si and HaCaT cells, as confirmed by analyses of PI labelling and cell morphology. Soluble factors from biofilm of single-species MSSA and mixed-species cultures induced the production of IL-6, NO and TNF-α by J744A.1 macrophages. The production of IL-6 and NO induced by the soluble factors from biofilm of mixed cultures was lower than that induced by the soluble factors from biofilm of single-species MSSA cultures, whereas the soluble factors from biofilm of C. albicans cultures induced only low levels of NO.ConclusionsSoluble factors from 36-h-old biofilm of C. albicans and MSSA cultures promoted cell death and inflammatory responses.

Development and characterization of a 3D oral mucosa model as a tool for host-pathogen interactions

“…Similarly, the ROMT also showed expression of cytokeratin 13. These results are in agreement with those previously shown by other authors (Garzón et al, 2009;de Carvalho Dias et al, 2017).…”

“…In addition, the association between S. aureus and C. albicans in the colonization of oral mucosa and dental prosthesis wearers with denture stomatitis has been reported (Ribeiro et al, 2012;Baena-Monroy et al, 2005). Not only the microorganisms themselves, but the secreted factors from their metabolisms can promote cell death and inflammatory response in monolayer cell culture (de Carvalho Dias et al, 2017). The secreted factors from the biofilm of mixed-species C. albicans and S. aureus cultures were more damaging to the monolayer epithelial cells than the secreted factors from the biofilms of single C. albicans and S. aureus cultures (de Carvalho Dias et al, 2017).…”

Candida spp./Bacteria Mixed Biofilms

“…This work evidenced that, in mixed biofilms, C. albicans can improve the pathogenicity of S. aureus, with key therapeutic repercussions. Also, de Carvalho Dias et al [120] stated that some soluble factors from single-and mixed-species biofilm of C. albicans and MSSA promote cell death and the inflammatory response. The soluble factors from mixed biofilms were the most toxic to the keratinocytes (NOK-si and HaCaT) cells.…”

Candida albicans increases the pathogenicity of Staphylococcus aureus during polymicrobial infection of Galleria mellonella larvae

“…The interactions between S. aureus and C. albicans are synergistic and result in increased mortality in animal models, which is associated with enhanced invasion, biofilm formation, exacerbated inflammatory responses and intrinsic resistance to antimicrobial chemotherapy [8–19]. Proteomic analysis of the interactions between S.…”