Molecular typing of Coxiella burnetii (Q fever).

Although we live in the age of genomics and the availability of complete genome sequences of Coxiella burnetii has increased our understanding of the genomic diversity of the agent, it is still somewhat a "query" microorganism. The epidemiology of Q fever is complex due to the worldwide distribution, reservoir and vector diversity, and a lack of studies defining the dynamic interaction between these factors. In addition Coxiella is an agent that could be used as a bioterror weapon. Therefore, typing methods that can discriminate strains and be used to trace back infections to their source are of paramount importance. In this chapter we provide an overview of historical and current typing methods and describe their advantages and limitations. Recently developed techniques such as MLVA and SNP typing have shown promise and improved the discrimination capacity and utility of genotyping methods for molecular epidemiologic studies of this challenging pathogen.