One-step determination of herpes simplex virus types I and II by polymerase chain reaction.

A rapid and sensitive one-step polymerase chain reaction (PCR) assay was developed for use in identifying type I and type II herpes simplex virus (HSV). Although the nucleotide sequences of the two HSV subtypes are quite similar, common and type-specific sequences 20 nucleotides in length could be deduced in the thymidine kinase gene. Oligonucleotide primers targeted to the type-specific regions generated products of different sizes that served to distinguish two HSV types. Type-specific PCR amplification products were verified by restriction enzyme digestion. Specificity of the HSV PCR was established by the lack of amplification of other herpes-group viruses including cytomegalovirus, Epstein-Barr virus, and varicella zoster virus. Extraction of DNA from clinical materials (throat swabs, vesicular swabs, cerebrospinal fluid and eye discharge) yielded an amplification product of the predicted size for each HSV type. Thus, this PCR system provides a rapid, sensitive and specific assay that can supplement the currently available modalities for detecting and typing HSV.