蜱斑点热群立克次体脱氧核糖核酸序列初步分析

Analysis of DNA sequences of spotted fever group rickettsia detected from ticks in Zhejing province

目的了解浙江省媒介蜱斑点热群立克次体带菌状况。方法通过扩增斑点热群立克次体外膜蛋白A基因片段,对浙江省金华市野兔、野猪寄生蜱标本进行检测分析。结果对343份蜱标本分47组进行检测,分别从1组龟形花蜱和1组镰形扇头蜱中扩增出DNA阳性条带;经测序分析,分别命名为ZJ42和ZJ43株片段。ZJ42株与R.sp JL-95株关系较近,该株在外ompA的575～580位点有6个碱基(AAATAT)的插入缺失,可能是一个新菌株或种。ZJ43株与马赛立克次体、Rickettsia BAR-29和Rickettsia rhipicephali关系较近。结论浙江省存在斑点热群立克次体的媒介蜱,应加强在媒介蜱,特别是镰形扇头蜱和龟形花蜱中对斑点热群立克次体的监测,并研究它们的致病性。

Objective To investigate the carriage of spotted fever group rickettsia by ticks collected in Zhejiang province.Methods Specific OmpA gene of spotted fever group rickettsia were amplified to detect tick samples taken from hares and boars in Jindong district.Results Specific OmpA genes were amplified in one group of Amblyomma testudinarium and one group of Rhipicephalus haemaphysaloides in 47 groups of 343 tick samples,which were named as ZJ42 and ZJ43 fragment respectively.ZJ42 was closely related to Rickettsia sp JL-95 and included Indel at 575-580 sites of AAATAT,which had never been reported.It suggested that ZJ42 could be a new strain or species.ZJ43 was closely related with Rickettsia BAR-29、Rickettsia massiliae Mtu 1 strain and Rickettsia rhipicephali.Conclusion The vector of spotted fever group rickettsia existed in Zhejiang.It is important to strengthen the surveillance on vector tick of spotted fever group rickettsia,especially on Amblyomma testudinarium and Rhipicephalus haemaphysaloides,and conduct research on their pathogenicity.