Work in our group is focussed on the development of films which can deliver bacteriophage to an infection site a following a ‘trigger’ event. Much of the current research on bacteriophage has focussed on the development and molecular biology of the phage themselves, with (arguably) delivery being something of an afterthought. However delivery is important: getting phage to the place of infection at a concentration and activity able to clear bacteria is critical if phage are to become widely used.
Two infection systems are considered here: wound infection and catheter associated urinary tract infection (CAUTI). These two infections cause the majority of nosocomial infections, but treatment with phage requires delivery technology.
We have developed a number of phage delivery systems: films containing phage which can be applied to wound dressings or urinary catheters which respond to a ‘trigger’ event. Using a trigger event to actuate phage delivery means that phage will be delivered at a high dose only when required. Trigger systems studied are temperature (elevated skin temperature in a wound being related to infection); pH (increase in urine pH related to Proteus mirabilis infection in the bladder) and hyaluronidase (a secretion enzyme from Staphylococcus aureus which breaks down hyaluronic acid in skin). Our systems have been tested in in-vitro biofilm models and are a capable of attenuating infection following the relevant trigger event.