No abstract

Four fluorescein isothiocyanate-labelled monoclonal antibody typing reagents were compared for intensity of fluorescence and sensitivity in confirming herpes simplex virus (HSV) in cell culture. A total of 125 (50 HSV type 1 [HSV-1] and 75 HSV-2) specimens positive for HSV were concurrently stained with type-specific monoclonal antibodies from Bartels (Bartels Immunodiagnostic Supplies, Inc., Bellevue, Wash.), Kallestad (Pathfinder; Kallestad Diagnostics, Chaska, Minn.), Diagnostic Products Corp. (DPC) (PathoDx; DPC, Los Angeles, Calif.), and Syva (Microtrak; Syva Co., Palo Alto, Calif.). Fifty cultured specimens not displaying HSV-associated cytopathic effect were also stained. Each of the four reagents confirmed the 50 negative cultures and 125 positive cultures. One HSV-1-positive culture was missed by the Kallestad antibody. Ten HSV-1 isolates displayed dull fluorescence when stained with the Syva HSV-2 reagent. The other three reagents stained only the HSV-1 well with these 10 specimens. The Syva and Bartels stains were brighter, in general, than the Kallestad and DPC stains. However, the Kallestad and DPC stains were brilliant enough to allow interpretation without hesitation. The differences in intensity and background staining emphasize the need for laboratories to routinely perform quality checks on their reagents and to test new products which become commercially available.

Highly sensitive and rapid results can be obtained by isolating herpes simplex virus from clinical specimens in simple cell culture with rhabdomyosarcoma (RD) cells. In this study, 3,186 clinical specimens were inoculated into locally produced, equivalent-age RD and mink lung (ML) cells. Of 727 positive isolates, all (100%) were isolated from RD cells and only 691 (95%) were isolated from ML cells. Furthermore, 162 of the positive isolates (22%) were isolated in RD cells earlier than in ML cells. RD cells are continuous and can be cultivated in house without decreasing sensitivity as the passage number increases. They produce a highly distinguishable cytopathic effect in response to herpes simplex virus and maintain intense confirmatory staining patterns.