COMPARATIVE-EVALUATION OF COLORIMETRIC MICROTITER PLATE SYSTEMS FOR DETECTION OF HERPES-SIMPLEX VIRUS IN CEREBROSPINAL-FLUID

In the past few years, application of the PCR to the detection of herp es simplex virus (HSV) DNA in the cerebrospinal fluid (CSF) from patie nts with encephalitis and meningitis has become standard laboratory pr actice. However, from an operational perspective, the true diagnostic value of PCR in this setting is yet to be realized because most labora tories subject the amplification products to lengthy probe hybridizati on procedures by Southern blotting. As alternatives to Southern blotti ng, we evaluated colorimetric microtiter plate (MTP) systems from Viro Med Laboratories, Inc, (PrimeCapture), CPG, Inc. (Quanti-PATH), and In c-star Corp. (GEN-ETI-K), in addition to a system developed at the May o Clinic with the PCR ELISA system (Boehringer Mannheim Corp,). We tes ted PCR products from 86 clinical CSF specimens submitted to our Molec ular Microbiology Laboratory. The CSF specimens used had to have suffi cient volume for comparative analysis. By conventional Southern blotti ng methods, 54 were positive and 32 were negative for HSV DNA. Compare d with Southern blotting, the sensitivity and specificity were 63.0 an d 100.0%, respectively, for the PrimeCapture system, 98.2 and 96.9%, r espectively, for the Quanti-PATH system, 95.2 and 100.0%, respectively , for the GEN-ETI-K system, and 100.0 and 96.9%;, respectively, for th e Mayo system. All four MTP systems had turnaround times 12 to 24 h le ss than that for Southern blotting. There were no significant differen ces in costs or technologist time between the Mayo system and Southern blotting, Other features of the Mayo system include type-specific gen otypic identification of HSV and the potential for determination of dr ug resistance by DNA sequencing. Overall, we found that colorimetric M TP systems were likely to improve test turnaround times and patient ca re at no additional cost.