浙江磐安地区啮齿动物嗜吞噬细胞无形体感染研究

Investigation for Anaplasma phagocytophilum infection in rodents in Pan'an region,Zhejiang Province

目的调查浙江省磐安地区啮齿动物无形体属嗜吞噬细胞无形体的自然感染状况,了解其分子生物学特性。方法在浙江省磐安地区低山田地里捕获多种啮齿动物230只(黄胸鼠、社鼠、褐家鼠、小林姬鼠、黄毛鼠、青毛鼠、大林姬鼠、白腹巨鼠、针毛鼠、黑线姬鼠和松鼠);解剖取肝脾;提取DNA,用巢式PCR扩增无形体属16SrRNA片段;PCR产物测序,并进行Blast同源性比较,最后采用MEGA4.0软件与GenBank登录的其它无形体属种株进行系统发生分析。结果 230只啮齿动物中,1只黄胸鼠、1只褐家鼠和2只白腹巨鼠肝脾标本检出无形体属16SrRNA片段,磐安地区野鼠无形体属立克次体的自然感染率为1.7%。3份阳性标本PCR产物测序,序列比对分析表明,从褐家鼠同时检出分别与嗜吞噬细胞无形体和浙江无形体株ZJ05/2009完全一致的序列,黄胸鼠和1只白腹巨鼠的序列与浙江无形体株ZJ05/2009完全一致。结论浙江省磐安地区野鼠检出致病性无形体属核酸,存在无形体属不同种株的复合感染感染。提示可能存在无形体病自然疫源地,需要进一步密切关注致病性无形体的人群感染情况。

To determine the prevalence and molecular biological characteristics of Anaplasma phagocytophilum （A. phagocytophilum） in wild rodents in Pan＇an region, Zhejiang Province, 230 wild rodents were randomly collected in fields in low hill. The rodent species detected included Rattus tanezumi, Niniventerconfucianus, Rattus norvegicus, Apodemus syl vaticus , Rattus losea , Berylmys bozversi Andeeson , Apodemus speciosus peninsula, Niniventer coxingi , Niniventer fulves- cens, Apodemus agrarius and squirrel. Spleens and livers were removed from the rodents and used to extract DNA for amplifi- cation. The 16S rRNA genes of Anaplasma were then amplified by nest PCR. The PCR products were sequenced and then compared in homology by using BLAST program. Phylogenetic analysis for 16S rRNA gene sequences published in GenBank was conducted by using Mega 4.0 software. Of 230 rodents, one R. tanezumi, one R. norvegicus and two N. coxingi were positive for Anaplasma 16S rRNA gene, with a positive rate of 1. 7%. PCR products from three positive samples were se- quenced. The nucleotide sequence analyses showed the sequences from R. norvegicus belonged to A. phagocytophilum and Anaplasrna strain ZJ05/2009, respectively. And those from one R. tanezumi and one N. coxingiwere 100% identical with Anaplasma strain ZJ05/2009 from Zhejiang. The 16S rRNA gene of A. phagocytophilurn was detected and Anaplasma infec- tion singly or doubly with different Anaplasma strains was confirmed in wild mice in Pan＇ an, Zhejiang. It is suggested that natural infectious loci for Anaplasma exist there and wild mice are reservoirs. It is necessary to pay a further attention to the infectious situation of Anaplasma causing disease in human especially, to illuminate whether Anaplasma strain ZJ05/2009 could cause human disease.