Abstract: Objective To examine the infection rate and genotype of Borrelia sp. among rodents, we surveyed rodent samples from Bayannur region of Inner Mongolia Autonomous Region, and to provide basic information of epidemic prevention and risk assessment for local area. Methods During 2015-2016, rodent samples were collected in Bayannur region by the trap-night method, and rodent spleen DNA samples were examined using specific PCR to detect the Borrelia sp. Results A total of 480 rodents were collected from Bayannur, and Meriones meridianus accounted for 174, and M. unguiculatus 124. The results showed that both were the predominant species in these areas. Borrelia sp. were identified from 8 (1.67%)when amplified by PCR targeting flaB gene and 16S rDNA, including 6 cases of M. unguiculatus and 2 cases of Phodopus sungorus, the positive rate were 7.14% and 4.84%, respectively. Sequence analysis of the amplification products showed identification of B. garinii and B. afzelii with 100% homology, respectively. Conclusion In this study, we confirmed the B. garinii and B. afzelii were main pathogens transmitting among rodents in Bayannur region, it is necessary to implement monitoring and prevention of Lyme diseases.

Key words: Rodent, Borrelia, Lyme disease, Relapsing fever

摘要： 目的 了解内蒙古自治区（内蒙古）巴彦淖尔地区鼠类分布、疏螺旋体感染及其基因型等，为该地疫情防控和风险评估提供基础数据。方法 于2015－2016年每年的4－6月、9－10月采用夹夜法捕获鼠类，采用特异性PCR扩增法对标本进行疏螺旋体检测，并通过测序和序列比对等进行疏螺旋体基因型分析。结果 共捕获鼠类480只，其中子午沙鼠（174只）和长爪沙鼠（124只）数量居多，为该地优势鼠种。鼠类脾脏标本经PCR检测，共发现8份疏螺旋体flaB和16S rDNA基因阳性标本，阳性率为1.67%，其中毛足鼠和长爪沙鼠的阳性率分别为7.14%（2/28）和4.84%（6/124）。对阳性标本基因片段进行序列分析发现，感染的疏螺旋体为Borrelia afzelii和B. garinii。结论 内蒙古巴彦淖尔地区鼠类携带的疏螺旋体以B.afzelii和B. garinii为主，应加强该病原体的检测和莱姆病防制。

关键词: 鼠类, 疏螺旋体, 莱姆病, 回归热