Coxiella burnetii immunogenic proteins as a basis for new Q fever diagnostic and vaccine development.

Coxiella burnetii is the etiological agent of the zoonosis Q fever, which can cause an acute or a chronic, life-threatening disease in humans. It presents a highly stable cell form, which persists in the environment and is transmitted via contaminated aerosols. Ruminants are considered as the main reservoir for human infections but are usually asymptomatic. Subclinical infection in these animals and the occurrence of serologically negative shedders hamper the identification of infected animals with the currently used diagnostic techniques. This suboptimal sensitivity limits reliable identification of infected animals as well as the well-timed implementation of countermeasures. This review summarizes compounds, focusing on C. burnetii seroreactive proteins, which were discovered in recent immunoproteomic studies. We analyzed these proteins regarding their localization, function, frequency of citation, differences seen in various host species as well as sensitivity and specificity. Finally, proteins useful for the development of new diagnostic test systems as well as subunit vaccines were discussed.