and biofilm analysis on host cells
All bacteria occupy natural niches in which they proliferate. Organisms that can be isolated from the environment present a concern as opportunistic pathogens which grow as biofilms in wounds. Likewise, the bacteria that make up the flora of the oral cavity have complex relationships within biofilms that ultimately contribute to pathogenesis in the oral cavity as well as in other organs of the body. In order to study such relationships among bacteria, it is necessary to inoculate and culture the organism under shear flow.
The BioFlux System is a microfluidic platform designed to run automated shear flow protocols for host-pathogen interaction experiments in high throughput. This microfluidic system replicates the physiological environment, and can be used for the controlled exposure of mammalian cell monolayers to pathogenic bacterial (or fungal) agents. Shear flow conditions enabled by the BioFlux system can be used to either stimulate physiological conditions (e.g. urinary tract, gastrointestinal tract, respiratory tract, blood stream) or used for introduction of organisms and buffers during uninterrupted microscopic observation. In vitro models can be developed for the study of host pathogen interactions that utilize both benefits of this system. For example, cystic fibrosis (CF), a genetic disorder affecting cellular ion transport, is complicated by chronic lung infections by a variety of opportunistic bacteria, including P. aeruginosa. Study of host-pathogen interactions in CF is germane to discovering how the infections are established and how to prevent them.
The attachment and growth of pathogenic E. coli on HRT-18 monolayers and were observed with a confocal microscope - in conjunction with a BioFlux system - by exciting and detecting the fluorophore (DAPI or mCherry) (Tremblay et al., 2015).
Tongue tissue was infected and stained with fluorescent-labelled PNA probes to target C. albicans (green) and S. aureus (red) to show the presence of bacteria and hyphae-invaded tissue. Particular strains of C. albicans and S. aureus penetrated the epithelium, adhered to, and co-invaded the tissue (a, b, e, f). This was analyzed in real time with the help of a BioFlux system (Schlecht et al., 2015).
Key BioFlux Advantages For Host-Pathogen Interaction Studies
Grow microbes under controlled shear flow and conditions that mimic physiological environments
Use different shear stresses to analyze how biofilms and other cells adhere to epithelial monolayers in vitro
Easily control media flow through the channels in order to perfectly replicate in vivo conditions
Carry out a wide variety of experiments, including the formation of dental plaque biofilms or hyphae formation on host cells