甘肃麦积山区媒介及宿主动物中莱姆病螺旋体检测及基因型别研究

目的 了解甘肃麦积山景区蜱及野鼠体内莱姆病螺旋体感染及其基因分型情况。方法 采用布旗法采集蜱标本,采用夹夜法捕捉野鼠。经种类鉴定后,提取病原体DNA,应用巢式PCR扩增鼠中莱姆病螺旋体5S-23S rRNA间隔区片段,对阳性产物进行限制性片段长度多态性(RFLP)分析。结果 共检测4个蜱种1 273只蜱标本,其中若蜱1 126只,成蜱147只,若蜱分组进行处理和检测,共分为67组,其中13组检测到莱姆病螺旋体DNA片段;成蜱15只检测阳性。检测4个鼠种42只野鼠,其中10只检测阳性,不同鼠种阳性率存在差别(χ²=16.93, P=0.00),4个鼠种中以大林姬鼠的阳性率为最高,达到33.33%。基因分型分析结果显示蜱及野鼠标本中莱姆病螺旋体为B. garinii 及B. afzelii基因型,其中B. garinii基因型占78.95%。结论 麦积山景区存在莱姆病螺旋体,并至少有B. garinii 及B. afzelii两种基因型。

Borrelia burgdorferi infection and their genotypes in ticks and rodents collected from Maijishan region,Gansu Province,China

We investigated Borrelia burgdorferi infection in ticks and rodents captured in Maijishan region and identified their genotypes in this study. Ticks were collected by dragging a cloth over the vegetation, rodents were collected by snaps. After species identification, DNA of pathogen was isolated from samples and detected by nested PCR targeting 5S-23S rRNA intergenic spacer of Borrelia burgdorferi. Positive samples were further analysed by restriction fragment length polymorphism (RFLP). Results showed that a total of 1 273 ticks including 1 126 nymphal ticks and 147 adult ticks in 4 species; 42 rodents including 4 species were tested for evidence of Borrelia burgdorferi by nested PCR; 15 adult tick samples, 9 rodents samples and 13 groups of nymphal ticks showed positive. The positive rates were different among the different rodent species, with Apodemus agrarius having the highest positive rates. RFLP analysis indicated that Borrelia burgdorferi in samples belonged to the genotype either B. garinii or B. afzelii. It's suggested that Borrelia burgdorferi exists in Maijishan region and there were at least two genotypes.