A bacteriophage infectivity assay to probe particle transport through mucus and biofilm matrices

Mucosal surfaces of the gastrointestinal, respiratory, and reproductive tracts provide lubrication and protection to the wet epithelium of these systems. Infections often involve the mucosal barrier, since it is the first point of contact with invading pathogens and the body interior. At times, bacteria can colonize and establish biofilms within mucus, resulting in chronic illnesses that respond poorly to traditional therapeutic approaches. Biocompatible nanoparticle based therapies, such as bacteriophage drug carriers, have been considered for treatment of biofilm associated infections. However, limited information is available regarding the ability of bacteriophage to penetrate the mucosal barrier and the biofilm matrix to effectively deliver therapeutics. Here, we describe a preliminary study to investigate the role of the mucus barrier surrounding bacterial biofilms when attempting to target matrix embedded cells with the filamentous bacteriophage M13. This work sets the stage for more in depth synthetic biology based engineering of bacteriophage that can effectively penetrate both complex barriers.