Our laboratory works with the obligate intracellular bacterial pathogen, Coxiella burnetii, the etiologic agent of Q fever and a category B biothreat agent. The long-term goal of this research is to understand the molecular pathogenic mechanisms involved in the host-pathogen interaction. To accomplish this broad goal, project in the lab are designed to test the molecular mechanisms employed by both the host and pathogen. Current pathogen studies include 1) broad survey of proteins secreted via a type 4 secretion system (T4SS) followed by determination of essentiality of each substrate for virulence and detailed analysis of mechanism of host modulation 2) survey of essential virulence loci identified by specific mutant screens, and 3) definition of the relative virulence of phylogenetically distinct isolate groups.