- Genotypic and phenotypic characterization of the thymidine kinase of ACV-resistant HSV-1 derived from an acyclovir-sensitive herpes simplex virus type 1 strain. Saijo, M., Suzutani, T., De Clercq, E., Niikura, M., Maeda, A., Morikawa, S., Kurane, I. Antiviral Res. (2002)