Glasgow Heather L, Zhu Haiying, Xie Hong, Kenkel Elizabeth J, Lee Carrie, Huang Meei-Li, Greninger Alexander L
Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, United States.
Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, United States.
J Clin Virol. 2023 Oct;167:105554. doi: 10.1016/j.jcv.2023.105554. Epub 2023 Jul 29.
Antiviral resistance in human herpes simplex viruses (HSV) remains a significant clinical challenge in immunocompromised populations. Although molecular tests have largely replaced viral culture for HSV diagnosis and molecular antiviral resistance testing is available for many viruses, HSV resistance testing continues to rely on phenotypic, viral culture-based methods, requiring weeks for results. Consequently, treatment of suspected HSV resistance remains largely empiric.
We used HSV whole genome sequencing and a database of previously characterized HSV acyclovir and foscarnet resistance mutations to evaluate the performance of genotypic antiviral resistance testing among 19 control strains compared to in-house plaque reduction assay (PRA) and 25 clinical isolates sent for reference lab PRA antiviral resistance testing.
Among control strains, 23/29 (79.3%) results were concordant, 5 (17.2%) were indeterminate, and 1 (3.4%) was discordant. Indeterminate results were caused by variants of uncertain significance (VUS), including mutations without published phenotypes and mutations with contradictory results. Among clinical isolates, 14/40 (35%) results were concordant, 17 (42.5%) were indeterminate, and 9 (22.5%) were discordant. All discordant results were in reportedly phenotypically-susceptible HSV-1 strains yet possessed resistance mutations. Three contained resistant subpopulations. 6/8 (75%) discordant phenotypes were concordant with resistant genotypes upon repeat PRA.
These data support the combination of genotypic and phenotypic testing to diagnose HSV resistance more accurately and likely more rapidly than phenotypic testing alone. Genotypic context of resistance mutations and the ability of viral strains to form plaques in culture may affect phenotypic resistance results, highlighting the limitations of PRA alone as a gold standard method.
人类单纯疱疹病毒（HSV）的抗病毒耐药性仍是免疫功能低下人群面临的重大临床挑战。尽管分子检测在很大程度上已取代病毒培养用于HSV诊断，且许多病毒都可进行分子抗病毒耐药性检测，但HSV耐药性检测仍依赖基于病毒培养的表型方法，结果需要数周时间。因此，对疑似HSV耐药性的治疗在很大程度上仍基于经验。
我们使用HSV全基因组测序以及先前已鉴定的HSV阿昔洛韦和膦甲酸钠耐药性突变数据库，与内部蚀斑减少试验（PRA）相比，评估19株对照菌株中基因型抗病毒耐药性检测的性能，并对25株临床分离株进行参考实验室PRA抗病毒耐药性检测。
在对照菌株中，23/29（79.3%）的结果一致，5（17.2%）不确定，1（3.4%）不一致。不确定结果由意义不明确的变异（VUS）引起，包括未公布表型的突变和结果相互矛盾的突变。在临床分离株中，14/40（35%）的结果一致，17（42.5%）不确定，9（22.5%）不一致。所有不一致的结果均出现在据报道表型敏感的HSV-1菌株中，但这些菌株存在耐药性突变。其中3株含有耐药亚群。在重复PRA时，6/8（75%）不一致的表型与耐药基因型一致。
这些数据支持联合使用基因型和表型检测，比单独使用表型检测更准确且可能更快地诊断HSV耐药性。耐药性突变的基因型背景以及病毒株在培养中形成蚀斑的能力可能会影响表型耐药性结果，凸显了单独将PRA作为金标准方法的局限性。
