title: Prevalence of Intrathecal Acyclovir Resistant Virus in Herpes Simplex Encephalitis Patients.
abstract: Herpes simplex encephalitis (HSE) is a life-threatening complication of herpes simplex virus (HSV) infection. Acyclovir (ACV) is the antiviral treatment of choice, but may lead to emergence of ACV-resistant (ACVR) HSV due to mutations in the viral UL23 gene encoding for the ACV-targeted thymidine kinase (TK) protein. Here, we determined the prevalence of intrathecal ACVR-associated HSV TK mutations in HSE patients and compared TK genotypes of sequential HSV isolates in paired cerebrospinal fluid (CSF) and blister fluid of mucosal HSV lesions. Clinical samples were obtained from 12 HSE patients, encompassing 4 HSV type 1 (HSV-1) and 8 HSV-2 encephalitis patients. HSV DNA load was determined by real-time PCR and complete HSV TK gene sequences were obtained by nested PCR followed by Sanger sequencing. All HSV-1 HSE patients contained viral TK mutations encompassing 30 unique nucleotide and 13 distinct amino acid mutations. By contrast, a total of 5 unique nucleotide and 4 distinct amino acid changes were detected in 7 of 8 HSV-2 patients. Detected mutations were identified as natural polymorphisms located in non-conserved HSV TK gene regions. ACV therapy did not induce the emergence of ACVR-associated HSV TK mutations in consecutive CSF and mucocutaneous samples of 5 individual patients. Phenotypic susceptibility analysis of these mucocutaneous HSV isolates demonstrated ACV-sensitive virus in 2 HSV-1 HSE patients, whereas in two HSV-2 HSE patients ACVR virus was detected in the absence of known ACVR-associated TK mutations. In conclusion, we did not detect intrathecal ACVR-associated TK mutations in HSV isolates obtained from 12 HSE patients.
authors.affiliation: Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hannover, Germany.|Department of Viroscience, Erasmus MC, Rotterdam, the Netherlands.
authors.forename: Johanna G
authors.initials: JG
authors.lastname: Mitterreiter
authors.affiliation: Department of Neurology, Erasmus MC, Rotterdam, the Netherlands.
authors.forename: Maarten J
authors.initials: MJ
authors.lastname: Titulaer
authors.affiliation: Department of Neurology, Erasmus MC, Rotterdam, the Netherlands.|Department of Viroscience, Erasmus MC, Rotterdam, the Netherlands.
authors.forename: Gijsbert P
authors.initials: GP
authors.lastname: van Nierop
authors.affiliation: Department of Viroscience, Erasmus MC, Rotterdam, the Netherlands.
authors.forename: Jeroen J A
authors.initials: JJ
authors.lastname: van Kampen
authors.affiliation: Department of Viroscience, Erasmus MC, Rotterdam, the Netherlands.
authors.forename: Georgina I
authors.initials: GI
authors.lastname: Aron
authors.affiliation: Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hannover, Germany.|Department of Viroscience, Erasmus MC, Rotterdam, the Netherlands.
authors.forename: Albert D M E
authors.initials: AD
authors.lastname: Osterhaus
authors.affiliation: Department of Viroscience, Erasmus MC, Rotterdam, the Netherlands.|Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hannover, Germany.
authors.forename: Georges M G M
authors.initials: GM
authors.lastname: Verjans
authors.affiliation: Department of Viroscience, Erasmus MC, Rotterdam, the Netherlands.
authors.forename: Werner J D
authors.initials: WJ
authors.lastname: Ouwendijk
mesh_terms: D000212:Acyclovir / Q000494:pharmacology*; D000328:Adult; D019943:Amino Acid Substitution / Q000235:genetics; D000998:Antiviral Agents / Q000494:pharmacology; D003710:Demography; D024882:Drug Resistance, Viral / Q000187:drug effects*; D020803:Encephalitis, Herpes Simplex / Q000134:cerebrospinal fluid / Q000821:virology*; D005260:Female; D018259:Herpesvirus 1, Human / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification / Q000502:physiology*; D018258:Herpesvirus 2, Human / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D015995:Prevalence; D013116:Spinal Cord / Q000473:pathology* / Q000821:virology*; D013937:Thymidine Kinase / Q000235:genetics; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D013937:Thymidine Kinase; D000212:Acyclovir