云南省泸西县啮齿动物携带立克次体调查

目的 调查云南省泸西县啮齿动物携带恙虫病东方体、无形体和埃立克体的状况,了解该类病原体在当地自然界中的保存状况和基因特征。方法 用鼠笼和鼠夹在云南省泸西县捕鼠,将捕获的动物种类鉴定后解剖取脾脏,活鼠取血。采用巢式PCR扩增脾脏的恙虫病东方体groEL基因,无形体和埃立克体的16S rRNA基因特异片段;测定PCR扩增阳性产物的DNA序列,对获得序列进行序列比对和系统进化分析。IFA法检测鼠血清中恙虫病东方体IgG抗体。结果 在泸西县共捕获啮齿动物10种225只。其中黄胸鼠36.89%(83/225)、大绒鼠35.11%(79/225)和中华姬鼠13.78%(31/225)为优势鼠种。获得鼠血清85份。鼠脾脏中检测到5株东方体groEL基因阳性标本,带毒鼠种为黄胸鼠2.41%(2/83)和大绒鼠3.80%(3/79)。同源性比较显示,这5株东方体的相似性在99.02%~100%之间,他们分别与GenBank中已知立克次体序列的相似性在98.75%~100%。系统发生树显示,5株OT与来自日本、泰国和中国安徽的菌株位于同一分支。3份16S rRNA阳性标本,其中1份埃立克体阳性,来源于大绒鼠;1份沃尔巴克氏体和1份巴尔通体阳性均来源于黄胸鼠。无形体均为阴性。埃立克体株序列比对显示与来自美国、中国和巴西的埃立克体基因同源性为98.0%~100%,并与分离自美国野外工作者皮肤的伊文氏埃立克体在同一分支。鼠血清恙虫病IgG抗体阳性7份,阳性率8.24%(7/85)。结论 该地区存在以黄胸鼠和大绒鼠为主要宿主的恙虫病自然疫源地。埃立克体、巴尔通体和沃尔巴克氏体在啮齿动物中也存在感染,需注意防控。

Investigation on Rickettsia carried by rodents in Luxi County,Yunnan Province

To investigate the status of rodents infected with orientia tsutsugamushi, Anaplasma and Ehrlichia in Luxi County, Yunnan Province, to understand the preservation status and genetic characteristics of these pathogens in local nature. Using rat-cage and rattrap to catch rats in Luxi County. The captured animals were classified identified and their spleen was cut off, and the live mice were collected blood. To amplify the oriental groEL gene and specific 16S rRNA fragments of Anaplasma and Ehrlichia in mouse spleen by nest PCR. The DNA sequence of positive products was determined and the sequence alignment and phylogenetic analysis were carried out. Detection of oriental IgG antibody in rat serum by IFA. A total of 225 rodents of 10 species were caught in Luxi County. Among them, the dominant species Rattus flavipectus 83(36.89%), Eothenomys miletus 79(35.11%) and Apodemus draco 31(13.78%). Obtained 85 rat serum. The oriental groEL gene was detected by pcr from 5 samples, 2 from Rattus flavipectus and 3 from Eothenomys miletus, with a sequence similarity of 99.02%~100%. The phylogenetic analysis showed that strains of tsutsugamushi were located in the same branch as the strains of japan, thailand and Anhui, china.Of the 16S rRNA genes detected in 3 other rat samples, 1 was Ehrlichia gene from the Eothenomys miletus,2 were Bartonella and Wolbachia genes from Rattus norvegicus. Anaplasma, and the Ehrlichia gene sequence was 98.0%~100% homologous to the strains of United States, China and Brazil. Phylogenetic analysis showed that it was most related to Erythrin in the United States。7 positive samples of tsutsugamushi IgG antibody were detected (8.24%). There are natural foci of scrub typhus in this area, with Ruttus flauipectus and Eothenomys as the main hosts, and a few rodents carry Ehrlichia, Bartonella or Wolbachia.