一组长角血蜱中检出莱姆病螺旋体和斑点热群立克次体复合感染

Detection of co-infection with Lyme spirochetes and Spotted fever group rickettsiae in a group of Haemaphysalis longicornis

目的了解浙江省山区野生动物和蜱中莱姆病、斑点热、埃立克体病（无形体病）的感染情况。方法采用巢式PCR对采集的鼠、蜱标本进行莱姆病伯氏疏螺旋体、斑点热群立克次体、埃立克体（无形体）特异性核酸片段检测分析。结果从121份鼠标本和105组蜱标本中检出阳性结果14份。鼠标本中检出伯氏疏螺旋体5S～23S rDNA间隔区片段1份和埃立克体（无形体）16S rDNA 5’端片段2份。蜱标本中检出阳性11份，包括伯氏疏螺旋体5S-23S rDNA间隔区片段3份和斑点热群立克次体外膜蛋白OmpA基因5’端片段8份。其中1组长角血蜱成虫标本为伯氏疏螺旋体和斑点热群立克次体复合感染，5S-23S rRNA基因间隔区和ompA基因片段均阳性，分别与伯氏疏螺旋体法雷氏基因型和马赛立克次体株等关系较近。结论在同一组长角血蜱成虫中同时检出莱姆病疏螺旋体和斑点热群立克次体复合感染。

Objective The present study was conducted to investigate the infection of Lyme disease, Spotted fever, Ehrlichiosis （anaplasmosisin） in wild animals and ticks in the mountain areas of Zhejiang province. Methods Nested polymerase chain reaction was used to amplify specific DNA sequences of Lyme spirochetes, Spotted fever group rickettsiae, Ehrlichia （ anaplasma ） from samples of mice and ticks. Results 14 positive samples were identified from 121 mice and 105 groups of ticks. Among mice samples, one positive 5S-23S rDNA intergenic spacer of Borreia burgdorferi and two 5＇ fragments of Ehrlichia （anaplasma） 16S rDNA were obtained. 11 positive results were detected from tick samples including three 5S-23S rDNA intergenic spacer regions of Borreia burgdorferi and eight 5＇ fragments of Spotted fever group rickettsiae outer member protein A gene. One group of adult ticks, Haemaphysalis longicornis, which had been collected from eastern mountain area were detected to have co-infected with Lyme spirochetes and Spotted fever group rickettsiae. The positive sequences of 5S-23S rDNA intergenic spacer and ompA gene were tested and analyzed as Lyme spirochetes while rickettsia which was closely related to Borrelia valaisiana and R. massilliae. Conclusion This was the first report about co-infection of Lyme spirochetes and Spotted fever group rickettsiae found in the same group of adult Haemaphysalis longicornis. It is very important to strengthen the surveillance program on tick-borne infectious disease and their pathogenic in vectors, wild animals and targeted high risk groups and to differentiate the clinical manifestation and diagnosis to extend the knowledge of tick-borne infectious diseases in Zhejiang.