IADR Abstract Archives
Quantitative proteomics elucidates host response to bacterial-fungal mixed-species biofilms
Objectives: Human microbiota composed of bacterial and fungal members perpetually interact with host cells. However, host cell interaction with bacterial and fungal mixed-species biofilms has not been properly investigated. Candida albicans, a commensal fungus in the human oral cavity can form mixed-species biofilms with transient colonizers such as Pseudomonas aeruginosa, which may act as a source for lung infections in compromised host populations. Herein, we comprehensively investigated the host epithelial cell interaction with bacterial-fungal mixed species biofilm using novel in-vitro models and quantitative proteomics.
Methods: Flow Cytometry assisted and haemocytometer based counting techniques were used to assess the viability of epithelial cells and to determine a suitable multiplicity of infection (MOI) during individual and mixed-species infection of epithelial cells. Single and mixed species biofilms were formed on epithelial cells in the in-vitro model and the cells were separated using Flow Cytometry Assisted Sorting (FACS). The biofilm formation was observed using Scanning Electron Microscopy (SEM) and Confocal Scanning Laser Microscopy (CSLM). The dynamic range of proteins extracted from different cells was analyzed using the quantitative proteomic method, iTRAQ®.
Results: There was a differential host response to bacterial and fungal biofilms. Bacterial biofilms significantly reduced the viability of epithelial cells in a shorter period of time (7 h) compared to the fungal biofilms (15 h). P. aeruginosa and C. albicans formed mixed species biofilms on in vitro epithelial cells model. SEM and CSLM images confirmed foregoing in-vitro observations. Quantitative analysis of proteins revealed that host-bacterial and host-fungal biofilms have differential expression profiles.
Conclusions: We have for the first time examined the epithelial cell interaction with bacterial-fungal mixed species biofilms using a quantitative proteomic approach, which unraveled new facets of host-microbial interaction. This new model will be an invaluable tool for researchers embarking on the studies of host response to microbial biofilms.
Methods: Flow Cytometry assisted and haemocytometer based counting techniques were used to assess the viability of epithelial cells and to determine a suitable multiplicity of infection (MOI) during individual and mixed-species infection of epithelial cells. Single and mixed species biofilms were formed on epithelial cells in the in-vitro model and the cells were separated using Flow Cytometry Assisted Sorting (FACS). The biofilm formation was observed using Scanning Electron Microscopy (SEM) and Confocal Scanning Laser Microscopy (CSLM). The dynamic range of proteins extracted from different cells was analyzed using the quantitative proteomic method, iTRAQ®.
Results: There was a differential host response to bacterial and fungal biofilms. Bacterial biofilms significantly reduced the viability of epithelial cells in a shorter period of time (7 h) compared to the fungal biofilms (15 h). P. aeruginosa and C. albicans formed mixed species biofilms on in vitro epithelial cells model. SEM and CSLM images confirmed foregoing in-vitro observations. Quantitative analysis of proteins revealed that host-bacterial and host-fungal biofilms have differential expression profiles.
Conclusions: We have for the first time examined the epithelial cell interaction with bacterial-fungal mixed species biofilms using a quantitative proteomic approach, which unraveled new facets of host-microbial interaction. This new model will be an invaluable tool for researchers embarking on the studies of host response to microbial biofilms.