EPIDEMIOLOGICAL STUDY ON LYME DISEASE IN THE FAR EASTERN COUNTRY

对中国北方地区、长江流域和韩国的媒介蜱和宿主动物进行了莱姆病伯氏螺旋体调查。采用5S-23S rRNA基因间间隔和鞭毛蛋白基因PCR-RFLP分析和序列分析，对上述来源和俄罗斯远东地区分离的伯氏疏螺旋体进行了分析。从中国北部和俄罗斯远东地区采集的过乳伊蚊分离物经鉴定为B.afzelii或B.garinii。B.garinii产生的RFLP型C是该地区的优势种，在日本常见，在欧洲不常见。此外，在朝鲜中部采集的日本依蚊分离株经鉴定为远东型B.garinii或b.f afzelii。从韩国研究人员获得的暂定为b .afzelii亲缘群的nipponensis分离株进行了基因间间隔序列和16SrRNA序列的鉴定。这些分离株与欧洲蓖麻伊蚊分离株和日本柱状伊蚊分离株Am501具有较高的相似性。在长江流域捕获的姬鼠和家鼠分离物分别被鉴定为阿夫泽伊氏贝氏菌亲缘群和新基因型。此外，该地区一株卵形家鼠的分离株与家鼠的分离株具有相同的特征。基于外表面蛋白A、B、C基因序列的系统发育分析表明，日本与欧洲之间存在garinii和B.afzelii的传播途径是俄罗斯远东、中国北方和韩国等远东国家。

We made Lyme disease borrelia survey of vector ticks and resevoir animals in Northern part of China and the Yangtze River valley, and Korea. Borrelia isolates from these sources and from far eastern Russia we got previously were analyzed by 5S-23S rRNA intergenic spacer and flagellin gene PCR-RFLP analysis and sequence analysis.Isolates from Ixodes persulcatus collected Northern China and far eastern Russia were identified as B.afzelii or B.garinii. B.garinii generate RFLP pattern C which is commonly found in Japan but not in Europe were dominant species in these area. Furthermore, isolates from I.nipponensis collected in central Korea were identified as B.garinii of far eastern type or B.afzelii. Isolates from I.nipponensis tentatively described as B.afzelii-related group obtained from Korean researcher were characterized on intergenic spacer and 16SrRNA sequences. These isolates showed relatively higher similarity values to B.valaisiana isolated from I.ricinus in Europe and strain Am501 from I.columnae in Japan. Isolates from Apodemus spp.and Rattus spp.captured in the Yangtze River valley were identified as B.afzelii-related group and new genotype, respectively. Also, one isolate from I.ovatus in the area showed the same feature to those from the Rattus spp. Further study to described new species is undertaken.By the phylogenetic analysis based on the sequence of outer surface protein A,B,and C,genes, transmission of B.garinii and B.afzelii between Japan and Europe via far eastern country, such as far east Russia, northern China, and Korea was suggested.