某部驻区蜱传斑点热自然疫源地调查

The investigation of natural focus of tick-borne spotted fever in a military base

目的了解某部驻区蜱传斑点热的自然疫源地情况。方法进行蜱类与啮齿动物调查,利用立氏立克次体190kD外膜蛋白A(R.rOmpA)基因序列设计引物,对683只蜱类标本和146个鼠类脏器标本进行PCR检测,随机抽取一株森林革蜱阳性扩增产物进行序列测定。结果调查地区存在3种蜱、5种啮齿动物;从森林革蜱、嗜群血蜱和啮齿动物脏器标本中检测斑点热立克次体DNA片段,阳性率分别为53.81%、7.41%和6.16%;所测序列与前苏联的DnS14株的同源性为100%,与我国检测的BJ90、HLJ054的同源性分别为88%和86%。结论调查地区存在与DnS14株型别一致的斑点热立克次体株。

Objective To investigate the natural focus of tick-borne spotted fever in a military base. Methods An investigation on ticks and rodents was conducted and a PCR method was developed with primers R.rOmpA190.70p and R.rOmpA190.701n designed on the basis of rOmpA gene, which was specific for examining spotted fever group rickttsiaes (SFGR). 683 ticks and 146 organs of mice were detected and a positive PCR product amplified from D. Silvarum specimen (named JL-02) was cloned and sequenced. Results Three species of ticks and five species of rodents were found in the area. The SFGR DNA was detected from D. Silvarum, Haemaphysalis concinna, organs of mice and the positive rate were 53.81%, 7.41% and 6.16% respectively. Its nucleotide sequence of 587 bp rOmpA and derived amino-acids showed 100% similarity with nucleotide sequence of DnS 14 from the former Soviet Union according to the result of CLUSTAL, which was different from the DNA sequences of strains previously detected in China. Conclusions Natural focus of tick-borne spotted fever existed in the area. The DNA sequence of SFGR was similar to that of DnS 14.