深圳市鼠类感染汉坦病毒的分子特征

目的 了解深圳市宿主动物携带汉坦病毒状况、病毒型别及分子特征.方法 笼日法捕鼠,计算鼠密度,确定鼠种构成.共捕获宿主动物472只,褐家鼠为优势鼠种,占87.29%.免疫荧光抗原阳性鼠肺标本中提取病毒RNA,应用汉坦病毒型特异性引物进行逆转录.套式PCR扩增M片段基因和核苷酸序列测定,对汉坦病毒进行基因分型和同源性分析.结果 21只来自我市不同区褐家鼠的鼠肺标本中均发现携带汉城型病毒,汉坦病毒M片段核苷酸同源性高达95.4%以上,属于同一亚型.系统进化树显示它们可以分为6个小进化分支,与SZ2083进化关系相对最近.但发现来源于地理位置较近的病毒株并没有显示出较高的基因组核苷酸序列的同源性,反而相隔较远的病毒株呈现出一致性.结论 深圳市汉坦病毒的主要宿主动物是褐家鼠,携带的汉城型汉坦病毒之间的核苷酸序列及其推导的氨基酸序列同源性较高,但也存在一定的差异.这种差异形成的原因有待进一步研究.

Study on the molecular characteristic of natural infection of rodents with Hantaviruses in Shenzhen city

OBJECTIVE: In order to investigate Hantavirus (HV) infection of captured rodents and to understand the genotypes and the molecular characteristic of Hantaviruses in Shenzhen. METHODS: The captured rodents were classified and the density of distribution was calculated. A total of 472 animals were captured, among which Rattus norvegicus was the dominant group. The total viral RNA was extracted from the lung tissues positive with HV antigens by immunofluorescent assay and gene sequence of M fragment was amplified with RT-nested-PCR by using the Hantavirus genotype specific primers. The amplified genes were then sequenced, and subjected to genotyping and homology analysis. RESULTS: The results of genotype analysis showed that the Hantaviruses taken from twenty-one lung specimens in Rattus norvegicus in Shenzhen city belonged to the Hantavirus type II (SEOV). Results in homology analysis suggested that the homology among twenty-one samples should be rather high with 95.4% of nucleotide sequence identity and they belonged to the same subtype. Phylogenetic tree analysis showed that they were branched into at least six different lineages, and were highly homologized with SZ2083. We also found that these virus strains had not shown more highly homology of nucleotide sequence in nearest district, whereas revealed consistency in farther district. CONCLUSION: The major hosts of Hantaviruses in Shenzhen city were Rattus norvegicus and the epidemic strains were genotyped as SEO-type. Nucleotide sequence and deduced amino acid sequence from different rodents were highly homologous, while nucleotide mutation had also been observed. Further studies are required to explore the possible viruses' sequence mutation.