摘要
采用在病毒培养液中加５～１０μｇ／ｍｌ胰酶的培养方法，将猪流行性腹泻病毒（ＰＥＤＶ）ＣＶ＿（７７７）适应于Ｖｅｒｏ细胞，并传４５代．细胞病变规律．经免疫荧光检查阳性，电镜观察可见典型冠状病毒粒子，猪传染性胃肠炎（ＴＧＥ）免疾荧光检查阴性，猪流行性腹泻（ＰＥＤ）血清可抑制细胞病变（ＣＰＥ）．ＰＥＤＶＣＶ＿（７７７）毒株１１、２５、２８、４０及４４代传代毒的毒价分别为１０￣（３．５）、１０￣（５．５）、１０￣（６．５）、１０￣（７．０）和１０￣（７．０）ＴＣＩＤ＿（５０）／０．３ｍｌ。以１１、２１及２２代的毒１０ｍｌ头口服接种未吃初乳仔猪，可使之典型发病，免疫荧光及电镜观察均呈阳性．分别以２５、２８及３１代毒０．５ｍｌ／头、１ｍｌ／头、２ｍｌ／头口服接种３日龄仔猪１８头．除０．５ｍｌ组有１头反应外，均未发病，攻毒试验的总保护率为８７．５％，对照组１００％发病．以２８代毒制备氢氧化铝灭活苗，后海穴位接种，主动免疫组８５．１９％保护，被动免疫组８５％保护，对照组１００％及９２．３％发病．
Abstract CV_(777) and K stranis of porcine epidemic diarrhea (PED) virus were adapted to grow in V eroand IBRSZ Cell lines with medium containing trypsill at 5- I opg/ml. At 45 and 1 5 passaSes,cultrucs infected with the cell-adapted virus showed a cytopathic effect (cPE ) and typical coronavirus particles were observed by electroll microscopy (EM ). Infected cells were detected positively for PE DV by immunofluoresence, but nesativcly for transmissible gastroenteritis (TGE ). CPEof the virus could be inhibited by an.tisera against PED virus. Virus titers of CV777 strain werel 0'. s. I of-s. 1 0,. s. 1 0:. o and 1 0,. o TCID,,/0. 3nil at 1 1, 25, 28, 10 and 44 pseeages, respectively.The peak of virus titer at 4 1 passase was detected 33 hours postinoculation. Typical disease wasshown in colostrum--deDrived piglets inoculated orally with I cull of virus --infected cultures at I l,2 1 and 22 passages. and small intestines were detected positively for PEDV by immunofluorescence. 1 8 3 day old pislets inoculated orally with 0' snll. I ml and Zml of virus--infected culturesat 25. 28 and' 3 1 passages, respectively, exhibited no clinical sisns except one inoculated with0. sml cultures. 87. 5% of the plglets were protected when challenged with strain of PED virus,' but the desease occured in all of the control piglets. A killed virus vaccine emulsified with aluminum hydroxide using cell--adapted virus at 28 passage was developed. 85. 19% of piglets wereprotected by active immunization and 85 % by passive immumization,respectively 1 but the diseaseoccured in 100% and 92. 3% of the control pigs,respectively.
