Rapid Differentiation of Herpes Simplex Virus Types 1 and 2 by Cytopathic Effect in BS-C-1 Cells

Conditions are defined under which herpes simplex virus (HSV) type 2 produces a characteristic cytopathic effect (c.p.e.) in African green monkey kidney (BS-C-1) cells. The BS-C-1 microplate c.p.e. test was simultaneously evaluated against immunological and biological marker procedures on 359 HSV strains. A BS-C-1 cell suspension was added to serial dilutions of HSV strains in Falcon Micro Test II plates and incubated at 36.5 °C in a 4% CO₂ atmosphere. When the infected cultures were examined microscopically, distinctive pseudopod-like extensions were seen in cultures infected with type 2 strains but not seen when the infecting virus was type 1, forming the basis for a differentiating test. The test was 100% accurate in differentiating between HSV-1 and -2 on a one test per specimen basis. The method is simple, rapid and requires no specialized reagents.