The use of Staphylococcus aureus rich in protein A in the detection of herpes simplex virus antigens

Herpes simplex virus (HSV) type 1 antigens were detected in infected human embryonic lung cells with the aid of specific antiserum and Staphylococcus aureus rich in protein A. When such staphylococci carrying specific anti-HSV IgG on their surface were interacted with various suspension of virus, a reduction in the initial virus titre of about 65% was obtained. However, no direct coagglutination was observed between cell-free supernatants of HSV or HSV-infected cells and sensitized staphylococci. When monolayers or suspended cells infected with the virus were treated with dilutions of specific anti-HSV antiserum followed by non-sensitized staphylococci (indirect method), an "aureola" of the bacteria was detected around the cells expressing the viral antigens. A similar picture was observed when infected cells were interacted directly with sensitized staphylococci. Viral antigens were detected already 12 hours post infection, well before the appearance of cytopathic effect. The sensitivity of the indirect method was found to be higher than that of the direct one and dependent on the multiplicity of infection and the serum dilution used. The method is proposed as a rapid means of identifying viral antigens in diagnostic and experimental virology.