Testing of herpes simplex virus for resistance to antiviral drugs.

Herpes simplex virus (HSV) infections can be treated efficiently by the application of antiviral compounds. Several drugs on the basis of acyclovir (ACV), penciclovir (PCV) and foscarnet (FOS) have been approved. Resistant viral isolates can be observed especially in immunocompromised patients, who are treated with antivirals for long time intervals.

Phenotypic and genotypic characterization of acyclovir-resistant clinical isolates of herpes simplex virus.

Sixteen herpes simplex virus type 1 (HSV-1) and four type 2 (HSV-2) isolates resistant to acyclovir (ACV) were characterized retrospectively for drug resistance. Phenotypic testing was performed by means of tetrazolium reduction assay and genotypic analysis was carried out by sequencing of thymidine kinase (TK) and DNA-polymerase (pol) genes. All strains were characterized as cross-resistant to penciclovir, brivudin and susceptible to cidofovir.