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To develop live cell culture HC virus vaccine, rabbit cell passage of Lapin-ized Hog Cholera（tHC) virus (HC RK-LPC) was used. Detection and assay of the LPC virus by mean:s of the two step E-interference method with s-wine kidney cell line SK-H and its clone CPK strain were studied. The re-suits are as follows:
The sensitivities of ST primary cells, SK-H and CPK swine kidney cell lines in growing LPC virus were compared using Viral titers. The SK -H cell line was found to be the most sensitive.
The HC LPC -China virus can grow and propagate in RK cells. The vi-ral titers in primary cells are higher than in secondary cells, and also higher than directly cultured Kidney and testical cell from rabbits inoculated with LPC-China virus.
The virus growth curve in LPC virus inoculated rabbit was studied by conq,aring the growth in tissue emulsion with the 5th and 10th passages of RK-LPC virus. The peak viral titers were 103•7 TCID50/ml in tissue e-nwlsion l on the 6th day after incubation), 105•3 TCID50 /ml in the 5th RK -LPC passage ( on the 5th day of incubation ) and 105•7 TCID50 /ml in the 10th RK-LPC paggage t on the 4th day of incubation ) .
The original tissue emulsion ( spllen and lymph node ) of LPC virus inoculated rabbits was END negative, but was END positive after only one passage in RK and ST cells or other kinds of cells. The END virus growth
curve using the two step E-interference virus was the same as mentioned above. Thus the viral titers also increase following the addition of passage number.
On the other hand when LPC-China 820th, RK -LPC 18th and the field isolated Kanagawa/ 1974 viruses were inoculated into the CPK cell line and challenged by the vesicular stomatitis virus, the reverse plaque formation was negative. However the reverse plaque formation was positive using the control viruses HC A76 and HC attenuated GPE- virus.Thus the virulent Hug cholera A76 strain may contain more than one strain of virus.
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