Protein array of Coxiella burnetii probed with Q fever sera

Coxiella burnetii is the etiological agent of Q fever. To identify its major seroreactive proteins, a subgenomic protein array was developed. A total of 101 assumed virulence-associated recombinant proteins of C. burnetii were probed with sera from mice experimentally infected with C. burnetii and sera from Q fever patients. Sixteen proteins were recognized as major seroreactive antigens by the mouse sera. Seven of these 16 proteins reacted positively with at least 45% of Q fever patient sera. Notably, HspB had the highest fluorescence intensity value and positive frequency of all the proteins on the array when probed with both Q fever patient sera and mouse sera. These results suggest that these seven major seroreactive proteins, particularly HspB, are potential serodiagnostic and subunit vaccine antigens of Q fever.