Molecular epidemiology of rabies and lyssaviruses infection in Southeast Asia

为了明确狂犬病病毒在东南亚动物中的传播运动和野生动物中的分布，本研究在泰国和印度尼西亚的狂犬病疫区采集了狂犬病动物、蝙蝠和野生大鼠的脑样本。提取脑总RNA，逆转录，PCR扩增（RT-PCR），直接测序并分析N和G基因。结果表明：1)通过测序和RFLP分析，来自泰国多个地区的61份样品均可分为至少6种n基因型。其中4个基因型在遗传标准和地理标准上具有较好的相关性，其余基因型在两个地区之间存在重叠。2)东北地区狂犬病分离株的n基因型与其他地区相似，但未得到详细鉴定。3)通过对泰国多个地区狂犬病分离株G基因的比较分析，得到的G蛋白氨基酸序列具有较高的同源性（97 ~ 98%），但与日本犬用疫苗RC-HL株同源性为88 ~ 89%。4)泰国南部地区50只野生大鼠和50只蝙蝠的溶血病毒N基因RT-PCR检测均阴性。5)目前，对印度尼西亚多个地区分离的140例狂犬病病毒的遗传分析正在取得进展。

In this study, to definite the infectious movement of rabies virus in animals and the distribution of lyssaviruses in wildlifes in Southeast Asia, brain samples of rabid animals, bats and wild rats were collected from enzootic areas of Thailand and Indonesia. Total RNA from brains was extracted, reverse-transcribed, amplified by PCR (RT-PCR), directly sequenced and analyzed for N and G genes.The results run as follows :1) All 61 samples from several areas of Thailand were separated into at least six N-genotypes by the sequencing and RFLP analyses. Of them, four genotypes indicated a good correlation between genetic and geographical criteria, and the remaining genotypes were overlap between two areas.2) The N-genotype of rabies isolates from the north-eastern area was similar to it of other regions but not idenntified in detail.3) A comparative analysis of G gene in rabies isolates from several regions of Thailand, revealed that the deduced amino acid sequences of the G proteins had a high homology (97-98%) among each other, but were 88-89% with the RC-HL strain, which is presently used for vaccine for dog in Japan.4) All samples of 50 wild rats and 50 bats from the south area in Thailand were negative for the detection of lyssavirus N gene by RT-PCR.5) At present, genetic analysis of 140 rabies isolated collected from several areas in Indonesia is the progressing.