云南省景洪市鼠类及媒介蜱中伯氏疏螺旋体感染状况调查

Investigation of vector and host infection of lyme disease in Jinghong,Yunnan

目的了解云南省景洪市鼠类及媒介蜱中伯氏疏螺旋体的感染状况及其携带的病原体特征。方法 2018年3月在景洪市景讷和大渡岗2个乡镇7个调查点采集蜱标本,在勐罕、勐养、嘎洒、景讷4个乡镇4个调查点采集鼠的肾脏、膀胱标本,提取样本DNA;采用实时定量PCR进行伯氏疏螺旋体recA基因检测;对recA基因阳性样本用巢式PCR扩增5S～23S rRNA基因间隔区,并对扩增产物进行测序及序列同源性比较。结果共采集牛、羊寄生蜱724只,经鉴定均为微小牛蜱;35只鼠均为黄胸鼠;524只蜱及35份鼠标本伯氏疏螺旋体培养结果均为阴性。对200份蜱recA基因检测发现阳性3份;35份鼠标本均为阴性。对3份阳性标本的5S～23S rRNA序列同源性进行分析,初步判定其为伽氏疏螺旋体。结论云南省景洪市蜱中存在伽氏疏螺旋体感染,微小牛蜱很可能是其传播媒介,应加强对当地人群、宿主及媒介的调查和监测。

Objective To understand the infection status and pathogenic characteristics of lyme disease in rats and ticks in Jinghong county of Yunnan province.Methods In March 2018,the specimens of ticks were collected from 7 villages in Jingne and Dadugang townships of Jinghong,and divided into two groups.The specimen in one group were used to culture Borrelia burgdorferi with BSK-Ⅱ medium and the specimen in another group were used to extract DNA for detection of carrier rate.The kidney and bladder specimens of rats were collected from 4 villages in Menghan,Mengyang,Gasa and Jingne townships to culture pathogens and extract DNA.The DNA samples were detected by real-time PCR for the recA gene.The positive samples of recA gene were detected by nested PCR for 5 S–23 S rRNA gene spacer,and the amplified products were sequenced and compared with sequence homology.Results A total of 724 Boophius microplus and 35 Rattus flavipectus were captured,but no B.burgdorferi strains were isolated from 524 ticks and 35 rats.Three of 200 ticks were positive for recA gene,while 35 rats were negative.The 5 S–23 S rRNA sequence homology analysis of the three positive specimens showed that they belonged to B.garinii.Conclusion There was infection of B.garinii in ticks in Jinghong,and Boophius microplus might be the vector.Therefore,the surveillance in local population,host and vector should be strengthened.