Document 0837
 DOCN  M9470837
 TI    Phenotypic and genotypic characterization of acyclovir-resistant
       varicella-zoster viruses isolated from persons with AIDS.
 DT    9409
 AU    Boivin G; Edelman CK; Pedneault L; Talarico CL; Biron KK; Balfour HH Jr;
       Dept. of Laboratory Medicine and Pathology, Minneapolis, MN; 55455-0392.
 SO    J Infect Dis. 1994 Jul;170(1):68-75. Unique Identifier : AIDSLINE
       MED/94284663
 AB    Phenotypic and genotypic analyses were done on 17 varicella-zoster virus
       (VZV) isolates recovered from 10 persons with AIDS (mean CD4 cell count,
       16.4/mm3) who had chronic VZV lesions. Eleven acyclovir-resistant
       isolates were recovered from 10 patients after a mean of 20.1 weeks of
       therapy. Six susceptible isolates were recovered before acyclovir
       treatment (n = 1), early during therapy (n = 4; mean time, 4.2 weeks),
       or after discontinuation of acyclovir (n = 1). Acyclovir-resistant VZV
       isolates were deficient in thymidine kinase (TK) or induced a TK with
       altered substrate specificity; all isolates were susceptible to
       foscarnet. Ten of 11 acyclovir-resistant mutants contained tk gene
       mutations, including single nucleotide substitutions in highly conserved
       binding sites (n = 2) as well as nucleotide deletions (n = 4) and
       insertions (n = 4). These findings suggest that multiple, nonuniform
       mutations within the tk gene are associated with acyclovir-resistant VZV
       phenotypes.
 DE    Acyclovir/*PHARMACOLOGY  Amino Acid Sequence  AIDS-Related Opportunistic
       Infections/*MICROBIOLOGY  Base Sequence  Cells, Cultured  Drug
       Resistance, Microbial  DNA, Viral  Genotype  Herpes
       Zoster/*COMPLICATIONS/MICROBIOLOGY  Herpesvirus 3, Human/DRUG
       EFFECTS/ENZYMOLOGY/*ISOLATION & PURIF  Human  Molecular Sequence Data
       Phenotype  Polymerase Chain Reaction  Support, Non-U.S. Gov't  Support,
       U.S. Gov't, P.H.S.  Thymidine Kinase/GENETICS/METABOLISM  JOURNAL
       ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
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