广西凤山县野鼠感染斑点热群立克次体的分子流行病学研究

Molecular epidemiology of spotted fever group rickettsiae infections in wild rodents from Fengshan County,Guangxi

目的调查广西壮族自治区凤山县野鼠感染斑点热群立克次体(spotted fever group rickettsiae,SFGR)的状况,了解其在当地流行的种类。方法用鼠笼在广西河池市凤山县捕捉野鼠,根据形态学特征与运用分子生物学方法对鼠种鉴定。解剖动物后取其脾脏组织提取总DNA样本,采用半巢氏PCR从样本中扩增立克次体外膜蛋白A(ompA),检测野鼠携带的斑点热群立克次体。对扩得DNA片段测序,并对获得的DNA序列进行同源性与系统进化分析。结果共捕获7种105只野鼠,除青毛鼠之外,从板齿鼠、小泡巨鼠、卡氏小鼠、锡金小鼠、黑缘齿鼠和罗赛鼠中检测到斑点热群立克次体,总阳性率为23.8%。基于ompA基因序列分析,检测到的斑点热群立克次体为敬信立克次体、饶氏立克次体和西伯利亚立克次体。结论广西壮族自治区凤山县的野鼠携带3种斑点热群立克次体,为斑点热的自然疫源地。因此应加强当地的蜱传立克次体病的监测与防控。

The aim of this study was to investigate the prevalence of spotted fever group rickettsia(SFGR)in wild rodents collected from Fengshan County in the Guangxi Zhuang Autonomous Region,and to determine their species.Wild rodents were captured in cages in Fengshan County,Hechi City,Guangxi Zhuang Autonomous Region.The rodents were identified according to morphological characteristics,and the findings were confirmed through molecular biology methods.Subsequently,spleen samples were collected,and DNA was extracted.The outer membrane protein A(ompA)gene was amplified with semi-nested PCR to determine the species of SFGR in captured wild rodents.After sequencing of the PCR products,homology and phylogenetic analyses of ompA gene sequences were performed.A total of 105 wild rodents belonging to seven species were captured.FGR was detected in six rodent species(Bandicota indica,Leopoldamys edwardsi,Mus caroli,Mus Pahari,Rattus andamanensis,and Rattus losea,but not Berylmys bowersi),and the total positivity rate was 23.8%.Three Rickettsia species,Candidatus Rickettsia jingxinensis,Rickettsia raoultii,and Rickettsia sibirica,were identified from analysis of the ompA gene sequence.This study revealed the presence of three species of SFGR infecting wild rodents from Fengshan County,Guangxi Zhuang Autonomous Region,thus suggesting that Fengshan County is a natural focus of tick-borne spotted fever.This study highlights the need to strengthen monitoring and prevention measures for rickettsiosis.