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Basic Characteristics of Mutations
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Mutation Site
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A143G |
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Mutation Site Sentence
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In both other strains, we identified amino acid substitutions already described in other ACV-resistant VZV strains: either Glu-->Gly at residue 48 or Arg-->Gly at residue 143. |
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Mutation Level
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Amino acid level |
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Mutation Type
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Nonsynonymous substitution |
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Gene/Protein/Region
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TK |
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Standardized Encoding Gene
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ORF36
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Genotype/Subtype
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- |
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Viral Reference
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VZV strain Dumas
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Functional Impact and Mechanisms
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Disease
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Acquired Immunodeficiency Syndrome
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Immune
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- |
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Target Gene
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-
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Clinical and Epidemiological Correlations
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Clinical Information
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- |
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Treatment
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ACV |
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Location
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- |
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Literature Information
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PMID
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10508017
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Title
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Phenotypic and genetic characterization of thymidine kinase from clinical strains of varicella-zoster virus resistant to acyclovir
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Author
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Morfin F,Thouvenot D,De Turenne-Tessier M,Lina B,Aymard M,Ooka T
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Journal
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Antimicrobial agents and chemotherapy
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Journal Info
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1999 Oct;43(10):2412-6
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Abstract
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Varicella-zoster virus (VZV) is a common herpesvirus responsible for disseminated or chronic infections in immunocompromised patients. Effective drugs such as acyclovir (ACV), famciclovir (prodrug of penciclovir), and foscarnet are available to treat these infections. Here we report the phenotypic and genetic characterization of four ACV-resistant VZV strains isolated from AIDS patients and transplant recipients. Sensitivity to six antiviral drugs was determined by an enzyme-linked immunosorbent assay, viral thymidine kinase (TK) activity was measured by comparing [(3)H]thymidine and 1-beta-D-arabinofuranosyl-[(3)H]thymine as substrates, and the TK gene open reading frame was sequenced. Three strains were found to be TK deficient, and the fourth was a mixed population composed of TK-positive and TK-deficient viruses. Each strain presented a unique TK gene mutation that could account for ACV resistance. In one strain, the deletion of two nucleotides at codon 215 induced a premature stop signal at codon 217. In another strain, a single nucleotide addition at codon 167 resulted in a premature stop signal at codon 206. In both other strains, we identified amino acid substitutions already described in other ACV-resistant VZV strains: either Glu-->Gly at residue 48 or Arg-->Gly at residue 143. According to our work and data previously reported on resistant VZV strains, there are three areas in the TK gene where 71% of the mutations described to date are located. These areas are putative candidates for a genotypic diagnosis of ACV resistance.
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Sequence Data
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AF162437-AF162440
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