Institute of Virology and Antiviral Therapy, German Reference Laboratory for HSV and VZV, Friedrich-Schiller University of Jena, Hans-Knoell-Strasse 2, 07745 Jena, Germany.
Antiviral Res. 2010 Jun;86(3):246-52. doi: 10.1016/j.antiviral.2010.03.002. Epub 2010 Mar 6.
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. In addition, three strains were resistant to foscarnet. Genotypic analysis revealed two to seven non-synonymous mutations in the TK gene of HSV-1 and one to seven non-synonymous mutations in the DNA pol gene of HSV-1 and 2 associated with the gene polymorphism. Seventeen strains contained at least one non-synonymous resistant-related mutation in the TK gene and three strains, which were additionally foscarnet-resistant, revealed one resistance-associated mutation in the DNA pol gene. In most strains, resistant-related mutations in TK gene represented frameshift mutations and single non-synonymous nucleotide substitutions of conserved gene regions. However, numerous amino acid changes could not be interpreted clearly as accounting for resistance. In conclusion, further studies, e.g. site-directed mutagenesis experiments are required to characterize mutations of the TK and DNA pol genes in ACV-resistant viral strains as part of viral gene polymorphism or as cause of drug resistance.
十六株单纯疱疹病毒 1 型（HSV-1）和四株 2 型（HSV-2）耐阿昔洛韦（ACV）的分离株被回顾性地进行了耐药性特征分析。表型检测通过四唑还原试验进行，基因分析通过胸苷激酶（TK）和 DNA 聚合酶（pol）基因的测序进行。所有菌株均表现为对喷昔洛韦、溴夫定的交叉耐药，对更昔洛韦敏感。此外，三株对膦甲酸钠耐药。基因分析显示，HSV-1 的 TK 基因中有 2 到 7 个非同义突变，HSV-1 和 2 的 DNA pol 基因中有 1 到 7 个非同义突变，与基因多态性有关。十七株至少在 TK 基因中有一个非同义耐药相关突变，三株额外对膦甲酸钠耐药的菌株在 DNA pol 基因中有一个耐药相关突变。在大多数菌株中，TK 基因中的耐药相关突变代表移码突变和保守基因区域的单个非同义核苷酸取代。然而，许多氨基酸变化不能明确解释为耐药的原因。总之，需要进一步的研究，例如定点诱变实验，以确定 ACV 耐药病毒株中 TK 和 DNA pol 基因的突变是病毒基因多态性的一部分还是耐药的原因。
