In Vitro Susceptibility of the Herpes Simplex Virus to Acyclovir / 대한피부과학회지

ABSTRACT

BACKGROUND: Acyclovir is a highly effective antiviral agent specifically inhibiting the replication of members of the herpes virus group, in particular the has been used extensively herpes simplex virus types 1 and 2 and the varicella zoster virus. Although acyclovir it has not caused for the treatment or prevention of herpes simplex and varicella zoster virus infections, significant changes in virus sensitivity. OBJECTIVE: The purpose of this study was to evaluate the sensitivity of HSV to acyclovir. METHODS: A total of 80 strains were used 43 strains of non-genital herpes and 37 strains of genital gerpes. These were isolated from 80 patients and were studied to evaluate their sensitivities to acyclovir by the plaque reduction assay. The methods employed to monitor the sensitivity of virus isolates rely on simple dose-response experiments, looking at the effects of increasing concentrations of acyclovir on infected cell culture specimen. The assay is based on quantified plaque counting. The sensitivity of virus strains are then expressed as ID50(concentrations of drug reducing viral cytopathic effect by 50%) and MIC(minimum inhibitory concentration). RESULTS: The results were summarized as follows. 1. The ID50 values of acyclovir for HSV ranged between 0.0625 - 4.0 microgram / ml. For non-genital herpes isolates the mean and median values were 0.459 microgram / ml (SD = 0.624) and 0.250 microgram / ml ; for genital herpes isolates these values were 0.649 microgram / ml (SD = 0.746) and 0.50 microgram / ml . 2. The MIC values of acyclovir for HSV ranged between 0.250 - 32 microgram / ml . For non-genital herpes isolates the mean and median values were 2.605 microgram / ml (SD = 5.270) and 1.00 microgram / ml ; for genital herpes isolates these values were 2.716 microgram / ml (SD = 3.015) and 2.00 microgram / ml . 5. 93.75%(75 strains) of HSV isolates were within the ranges of sensitive HSV strains for acyclovir. CONCLUSION: We are concerned about the resistance of viruses to antiviral drugs, but so far, this has not been documented to be a big problem. With the increasing interest and ability to measure sensitivity of viruses to antiviral drugs we will find out more about viral resistance and its clinical significance.