森林革蜱经期传播莱姆病伽什螺旋体的动力学研究

A kinetic experiment of the potential of Dermacentor silvarum in trans-stadial transmission of Borrelia garinii

目的研究明确甘肃林区森林革蜱传播莱姆病的媒介作用。方法森林革蜱自然感染伯氏疏螺旋体,采用BSK-Ⅱ培养基培养,多克隆和单克隆鉴别试验;经期传播能力,以实验室培育的非感染森林革蜱刺叮人工感染21 d的阳性KM小鼠,利用分离培养和PCR方法检测蜱对伽什螺旋体的保持能力以及体内螺旋体对敏感动物的感染能力。结果接种森林革蜱62组,有3组培养出伯氏疏螺旋体,培养的总阳性率为4.84%;通过经期动力学实验,森林革蜱对莱姆病伽什螺旋体的保持能力不能跨越消化、蜕皮阶段,蜕化后的森林革蜱不再携带伽什螺旋体。结论森林革蜱虽然自然感染伯氏疏螺旋体,但不具备经期传播能力,作为莱姆病媒介的可能性不大。

Objective To identify the role of vector of Dermacentor silvarum in the forest region in Gansu Province in transmitting Lyme disease. Methods Naturally infected Borrelia burgdorferi in Dermacentor silvarum were isolated and cultured using BSK - II culture medium and identified using polyclonal and monoclonal tests;The trans-stadial transmission potential was identified by the following procedure：Let the laboratory-bred Dermacentor silvarum without infection sting positive KM mice on day 21 after artificial infection;the Borrelia burgdo^Ceri strains were isolated from Dermaceator silvarum, cultured and identified by PCR methods to evaluate the ability of Derrnacentor silvarum in reser- ving Borrelia garinii as well as the infection rate of in vivo Borrelia garinii in sensitive animals. Results A total of 62 groups of Dermacentor silvarum were inoculated, 3 of which were positive for Borrelia burgdorferi cultivation, the positive rate was 4.84%. Trans-stadial transmission kinetic experiments showed that the ability of Dermacentor silva- rum for reserving the Lyme disease Borrelia garinii could not cross digestion and molting stages. Dermacentor silvarum after molting period no longer carried Borrelia garinii. Conclusion Although Dermacentor silvarum ticks are sensi- tive to natural infection of Borrelia burgdorferi, they are unable to perform trans-stadial transmission of Borrelia gari- nil, thereby having a low potential for serving as vectors of Lyme disease.