Development Of A Robust Cell Culture Model To Investigate The Therapeutic Potential Of Clostridium Difficile Bacteriophages

Clostridium difficile infection is usually associated with long stays in hospitals and extended antibiotic use. Current treatment of the infection is with further use of broad spectrum antibiotics. The bacterium is becoming more resistant to antibiotics, therefore alternative treatments are being sought. One of which is bacteriophage therapy. There have been numerous in vitro and animal based studies designed to observe the efficiency of phages against C. difficile, however none of these have considered the potential interactions both may have with the gastrointestinal epithelial cell layer. This study aimed to develop and optimise a cell culture model which could be used to investigate the interactions and dynamics of bacteriophages and C. difficile within a natural setting designed to mimic the gastrointestinal tract. Results showed that C. difficile levels dropped further after phage treatment in the presence of cells compared to with bacteriophages alone. Phages and C. difficile were enumerated with varying levels of mucus and with different treatment regimens. Interestingly, the interactions changed in the presence of mucus. Bacteriophages were generally more active against planktonic C. difficile rather than against bacteria that had attached to a mucus layer. Moreover phages were able to attach to the epithelial cells in the presence of mucus. The mucin levels of HT29-MTX-E12 were measured by indirect ELISA. Despite extensive optimisation of the indirect ELISA the mucin levels were unable to be quantified. The results of this study not only demonstrates the successful use of the cell culture model but also highlights the potential of bacteriophage therapy against C. difficile infection.