Open Access Research article

Microarray of surface-exposed proteins of rickettsia heilongjiangensis for serodiagnosis of Far-eastern spotted fever

Yong Qi, Wenping Gong, Xiaolu Xiong, Jiafu Jiang, Yawei Wang, Jun Jiao, Changsong Duan and Bohai Wen*

Author Affiliations

State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, 20 Dong-Dia-Jie Street, Fengtai, Beijing, China

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BMC Infectious Diseases 2014, 14:332  doi:10.1186/1471-2334-14-332

Published: 17 June 2014



Far-eastern spotted fever (FESF) is an important emerging infectious disease in Northeast Asia. The laboratory diagnosis of FESF in hospitals is mainly based on serological methods. However, these methods need to cultivate rickettsial cells as diagnostic antigens, which is both burdensome and dangerous.


Eleven surface-exposed proteins (SEPs) were identified in our previous study and their recombinant proteins (rSEPs) fabricated on a microarray were serologically analyzed with seventeen paired sera from patients suffered from FESF in this study.


All the rSEPs showed sensitivities of between 53% and 82% to acute-phase sera and of between 65% and 82% to convalescent-phase sera, and all the rSEPs except rRplA showed specificities of between 80% and 95%. The combination assay of two, three, or four of the four rSEPs (rOmpA-2, rOmpB-3, rRpsB, and rSdhB) showed better sensitivities of between 76% and 94% to the acute-phase sera or between 82% and 100% to the convalescent-phase sera and acceptable specificities of between 75% and 90%.


Our results suggest that the four rSEPs are more likely candidate antigens for serological diagnosis of FESF.

Far-eastern spotted fever; Rickettsia heilongjiangensis; Protein microarray; Serological diagnosis