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Basic Characteristics of Mutations
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Mutation Site
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T225I |
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Mutation Site Sentence
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Although the frequency of amino acid substitutions were not significantly different, a total of 16 amino acid substitutions in the polymerase domain occurred only in tenofovir-experienced isolates compared to tenofovir-naive isolates, including S117Y, S117C, I121N, T128I, M129L, R138K, R138E, L140P, V142A, I163V, L217R, N238H, R242K, K270R, V278I, and R280S. Positions R110G, Y126H, T128S, W153R, L220I, T225I, P237H, T259S and H271C were highly polymorphic in tenofovir-naive compared to tenofovir-experienced isolates. No mutations known to cause tenofovir resistance (L180M, A181I/V, A194T, M204V/I, V214A, Q215S, N236T) or lamuvudine (3TC) resistance (L80V/I, I169T, V173L, L180M, A181T, T184S, M204V/I/S, Q215S) were observed. Absence of these mutations was also confirmed using the INNO-LiPA HBV DR v3 commercial kit (Innogenetics, N.V., Gent, Belgium) |
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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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P |
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Standardized Encoding Gene
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P
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Genotype/Subtype
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A |
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Viral Reference
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X02763.1
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Functional Impact and Mechanisms
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Disease
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Hepatitis B Virus Infection
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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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Y |
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Treatment
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Tenofovir(TDF) |
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Location
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South Africa |
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Literature Information
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PMID
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31248149
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Title
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Frequency of Hepatitis B Virus Resistance Mutations in Women Using Tenofovir Gel as Pre-Exposure Prophylaxis
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Author
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Baxter C,Ngcapu S,Blackard JT,Powell EA,Penton PK,Abdool Karim SS
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Journal
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Viruses
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Journal Info
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2019 Jun 19;11(6):569
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Abstract
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Intermittent use of a single antiretroviral agent in the presence of a replicating virus could potentially increase the development of antiviral resistance. The pericoital, before-and-after sex, dosing regimen used in the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 tenofovir gel trial meant that women who were infected with hepatitis B virus (HBV) were exposed intermittently to tenofovir during their participation. The impact of this dosing regimen on HBV resistance was assessed by amplification of the HBV polymerase region from 37 stored plasma samples of women who were HBV surface antigen positive. All samples belonged to HBV genotype A. None of the known tenofovir resistance mutations (M240V/I, L180M, A194T, V214A, N238T) were identified in any individuals. While it is reassuring that no resistance mutations were found among women using topical tenofovir, the rapidly expanding access to oral tenofovir-containing HIV pre-exposure prophylaxis (PrEP), with higher systemic exposure to the drug, makes monitoring for potential HBV drug resistance important.
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Sequence Data
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-
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