Investigations on Rickettsia in Ticks at the Sino-Russian and Sino-Mongolian Borders, China Lijuan Liu, 1 Qian Chen, 1 Yu Yang, 1 Jiancheng Wang, 1 xiaomei Cao, 1 Sheng Zhang, 2 Hong Li, 2 Yong Hou, 3 Fuxiang Wang, 4 and Baoliang Xu 1 Abstract To describe the prevalence of Rickettsia in ticks at the Sino-Russian and Sino-Mongolian borders, a total of 292 ticks were collected and tested by conventional PCR assays. The prevalence of Rickettsia was 53.4%, and phylogenetic analysis showed that they belonged to R. raoultii species after alignment for the ompA, ompB, and gltA genes, respectively. Coxiella burnetii DNA was detected for 14%, and no Ehrlichia, Borrelia burgdorferi, and Babesia species were found. Co-infection of two pathogens was 9.9%, and no co-infection with three or more pathogens was found. This study suggested Rickettsia was the most common pathogen in the ticks and co- infection was found. The findings might be helpful to provide advice on the prevention and control of tick-borne disease potential for tourists and residents. Key Words: Rickettsia—Ticks—Co-infection. Introduction R ecently, the number of rickettsioses caused by the obligate intracellular bacteria spotted fever group (SFG) Rickettsia spp. is increasing rapidly (Ferna ´ndez de Mera et al. 2013, Jia et al. 2013a,b). These zoonoses are now recognized as emerging or re-emerging diseases that are transmitted by the bite of infected ticks, and they have been described worldwide. Rickettsial diseases present high fever, headache, and maculopapular rash. During the past 10 years, more than 500 rickettsioses cases were reported to National Center of Disease Prevention and Control of China (Wen et al. 2014). Most of these cases were diagnosed by clinical manifestations, and some cases were confirmed by serology or commercially available genus-specific PCR assay; only a few cases were diagnosed by pathogen culture in the laboratory. Borders be- tween some countries are exotic places and attractive to tourists; thus, whether the local residents or tourists are under the pressure of rickettsial diseases needs to be considered. The situation of ticks carrying Rickettsia and other pathogens are of utter importance for providing the first-hand data for the prevention and control of tick-borne diseases. In the present study, we describe the prevalence of Rick- ettsia in ticks at the Sino-Russian border and the Sino- Mongolian border in Inner Mongolia, China, as well as co- infection with other DNA pathogens, so as to provide data to prevent and control rickettsial diseases. Materials and Methods Study area The Inner Mongolia Autonomous Region is located in the north of China, bordering Mongolia and Russia. It is the third largest subdivision of the country, spanning about 1,200,000 km 2 . Ganqimaodu (GQMD) and Heish- antou (HST) are the regions of naturalistic importance located at the Sino-Mongolian and Sino-Russian borders, respectively (Fig. 1). These landscapes are characterized by a wide diversity of geology, vegetation, and landscape features, marked by the presence of watercourses and great grasslands, which are dedicated to rearing and graz- ing of farm animals. Tick collection and identification Adult ticks were collected from vegetation and domestic animals at two sites from May to June of 2013. Verbal au- thorization for collection of feeding ticks was obtained from 1 Institute of Health Quarantine, Chinese Academy of Inspection and Quarantine, Beijing, P. R. China. 2 Department of Health and Quarantine, Inner-Mongolia Entry-Exit Inspection and Quarantine Bureau, Hohhot, P. R. China. 3 Department of Health and Quarantine, Heilongjiang Entry-Exit Inspection and Quarantine Bureau, Harbin, P. R. China. 4 Department of Infectious Diseases, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, P. R. China. VECTOR-BORNE AND ZOONOTIC DISEASES Volume 15, Number 12, 2015 ª Mary Ann Liebert, Inc. DOI: 10.1089/vbz.2014.1732 785