title: Asymptomatically shed recombinant herpes simplex virus type 1 strains detected in saliva.
abstract: Herpes simplex virus type 1 (HSV-1) is a ubiquitous pathogen infecting most individuals worldwide. The majority of HSV-1-infected individuals have no clinical symptoms but shed HSV-1 asymptomatically in saliva. Recent phylogenetic analyses of HSV-1 have defined three genetic clades (A-C) and recombinants thereof. These data have all been based on clinical HSV-1 isolates and do not cover genetic variation of asymptomatically shed HSV-1. The primary goal of this study was to investigate such variation. A total of 648 consecutive saliva samples from five HSV-1-infected volunteers was collected. Asymptomatic shedding was detected on 7.6 % of the days from four subjects. The HSV-1 genome loads were quantified with real-time PCR and varied from 1x10(2) to 2.8x10(6) copies of virus DNA (ml saliva)(-1). Phylogenetic network analyses and bootscanning were performed on asymptomatically shed HSV-1. The analyses were based on DNA sequencing of the glycoprotein I gene, and also of the glycoprotein E gene for putative recombinants. For two individuals with clinical HSV-1 infection, the same HSV-1 strain was shed asymptomatically as induced clinical lesions, and sequence analyses revealed that these strains clustered distinctly to clades A and B, respectively. For one of the subjects with no clinical HSV-1 infection, a recombinant strain was identified. The other truly asymptomatic individual shed evolutionarily distinct HSV-1 strains on two occasions. The first strain was classified as a recombinant and the other strain clustered in clade A. High replication rates of different strains in the same person may facilitate the creation of recombinant clinical HSV-1 strains.
authors.affiliation: Department of Clinical Virology, Göteborg University, Guldhedsgatan 10B, S-413 46 Göteborg, Sweden.
authors.forename: Jan Åke
authors.initials: JÅ
authors.lastname: Liljeqvist
authors.affiliation: Department of Dermatovenereology, Göteborg University, Guldhedsgatan 10B, S-413 46 Göteborg, Sweden.
authors.forename: Petra
authors.initials: P
authors.lastname: Tunbäck
authors.affiliation: Department of Clinical Virology, Göteborg University, Guldhedsgatan 10B, S-413 46 Göteborg, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Norberg
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D005260:Female; D006561:Herpes Simplex / Q000503:physiopathology / Q000821:virology; D018259:Herpesvirus 1, Human / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D006801:Humans; D008297:Male; D010802:Phylogeny; D011995:Recombination, Genetic; D012463:Saliva / Q000821:virology*; D017422:Sequence Analysis, DNA; D017201:Virus Shedding
chemical_list: D004279:DNA, Viral