Isolation of Japanese encephalitis and Getah Viruses by Aedes albopictus Clone C6/36 Cells and by Suckling Mouse Brain Inoculation, in Nagasaki, 1980

18,000匹の野外採集コガタアカイエカ180プールと,1例の脳炎患者死后脳材料からのウイルス分離を,ヒトスジシマカ培養細胞クローンC6/36と乳呑マウス脳内接種(SMB)により実施した.日本脳炎(JE)ウイルスは17プールの蚊材料と脳炎患者死后脳材料からC6/36で分離されたが,SMBでは8プールの蚊材料から分離された.SMBで分離陽性でC6/36での分離陰性の1プールに対して,C6/36で分離陽性,SMBで分離陰性プールは10存在し,脳材料からのウイルス分離もSMBでは陰性であった.ゲタ(GET)ウイルスは5プールの蚊材料からC6/36で分離され,このうちの2プールからはSMBでも分離された.C6/36とSMBの両方で分離陽性であった株と,C6/36でのみ分離陽性であった株の間でウイルスの中和反応および,C6/36とBHK細胞での平板効率に関する限り有意の差を認めることは出来なかった.C6/36によるウイルス分離成績がSMBに比して良い結果が得られたのは,C6/36がSMBよりも高い感度でこれらのウイルスを野外材料から検出できる結果であると考えられる.Virus isolation was performed from field-caught female Culex tritaeniorhynchus and from postmortem brain materials of an encephalitis patient by inoculation into Aedes albopictus clone C6/36 cells and into suckling mouse brains (SMB). From 18,000 mosquitoes in 180 pools, Japanese encephalitis (JE) virus was isolated from 17 pools by C6/36 cells, in contrast to 8 pools by SMB. Seven pools with positive JE virus isolation by SMB were also with positive results by C6/36 cells. There was a single pool with positive JE virus isolation by SMB with negative result by C6/36 cells. Inoculation into SMB could not detect JE virus from 10 mosquito pools and postmortem brain materials which yielded JE virus by C6/36 cells. Getah (GET) virus was detected from 5 mosquito pools by C6/36 cells, and 2 out of the 5 pools also yielded GET virus by SMB. A single pool which produced JE and GET viruses by C6/36 cells produced only JE virus by SMB. No significant difference was observed between the virus strains isolated from mosquito pools which yielded the virus by both methods and the virus strains isolated only by C6/36 cells, in terms of neutralization test and of plating efficiency on C6/36 cells at 28℃ and that on BHK21 cells at 37℃. The results indicate that C6/36 cells have higher sensitivity than SMB to detect JE and GET viruses from field materials