Method for measuring antiviral susceptibility of herpes simplex virus type 2 and establishment of resistant strain.

Objective To develop the method for measuring antiviral susceptibility and to establish an acyclovir(ACV) resistant herpes simplex virus type 2 (HSV-2). Methods Baby hamster kidney cells were inoculated with HSV-2, and ACV was added to the medium in various concentrations. After 72 hours incubation, plaques were counted and the 50% inhibiting concentration(IC50)was calculated. HSV-2 was incubated in the presence of ACV for 9 passages. The IC50 of ACV was determined after the 3rd, 6th and 9th passage. Results The IC50 of ACV to HSV-2 Sav was 1.1μg/mL. In the presence of ACV, emergence of drug resistance was observed after passage 3; the IC50 of ACV after the 3rd, 6th and 9th passage was 8.4μg/mL,56.9μg/mL and 121.3μg/mL respectively. Conclusion Plaque reduction assay is an efficient method for determination of antiviral drug susceptibility of HSV and the establishment of ACV-resistant strain is essential for the study of resistance.