Grant: Emerging Team Grant: Canadian Microbiome Initiative - Full Application

All exposed surfaces of the human body harbour a rich community of microorganisms such that there are more bacterial cells on or in the human body than there are human cells. In general these are beneficial (commensal) bacteria that are essential for health. When the normal balance of organisms in these communities is disrupted or when they get to body sites where they are not supposed to be, they can cause disease. In addition, lurking among the commensal bacteria are pathogens. Their numbers are held in check by the commensals and host defences, yet opportunities may present where they can cause an infection. This is particularly true of the upper airways (nose, throat, mouth, pharynx and sinuses) that carry bacteria that are pathogens of the lower airways (lungs). Many pathogenic bacteria such as Streptococcus, Staphylococcus, Haemophilus and Neisseria are commonly found in healthy individuals without causing disease. The focus of this application will be to define the normal microbiota in the respiratory tract and investigate how these commensal bacteria inhibit or activate the pathogens. Understanding these interactions may lead to new ways to control these pathogens. In many chronic airway infections (such as in cystic fibrosis and bronchiectasis) multiple bacterial species contribute to disease including pathogens missed by conventional clinical microbiology. This study will also examine the microbiology of these infections.