title: Laboratory efforts to cultivate noroviruses.
abstract: Noroviruses (NoVs) are a leading cause of gastroenteritis worldwide and are recognized as the foremost cause of foodborne illness. Despite numerous efforts, routine cell cultures have failed to yield replicating NoV. This paper describes methods used to try to grow NoV in vitro in two laboratories. Cells (A549, AGS, Caco-2, CCD-18, CRFK, CR-PEC, Detroit 551, Detroit 562, FRhK-4, HCT-8, HeLa, HEC, HEp-2, Ht-29, HuTu-80, I-407, IEC-6, IEC-18, Kato-3, L20B, MA104, MDBK, MDCK, RD, TMK, Vero and 293) were cultured on solid or permeable surfaces. Differentiation was induced using cell culture supplements such as insulin, DMSO and butyric acid. In some cases, the cells and the NoV-containing stool samples were treated with bioactive digestive additives. Variables evaluated in cultivation experiments included the method of preparation of the virus inoculum, the genotype of the virus, conditions for maintenance of cell monolayers, additives in the maintenance medium and the method of inoculation of the cells. Serial blind passage studies were performed routinely. In addition to evaluation for CPE, evidence of virus replication was sought using immunofluorescent assays to detect newly produced viral capsid antigen and RT-PCR assays to detect the viral genome. Although some infected cultures remained NoV positive by RT-PCR for up to five passages and an occasional cell in a monolayer showed evidence of specific immunofluorescence, no reproducible NoV-induced CPE was observed and all RT-PCR results that were positive initially were negative following continued passaging. Thus, attempts to develop a method for the cultivation of NoV were unsuccessful.
authors.affiliation: Diagnostic Laboratory for Infectious Diseases and Perinatal Screening, National Institutes for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands.
authors.forename: Erwin
authors.initials: E
authors.lastname: Duizer
authors.affiliation: Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Kellogg J
authors.initials: KJ
authors.lastname: Schwab
authors.affiliation: Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Frederick H
authors.initials: FH
authors.lastname: Neill
authors.affiliation: Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Atmar
authors.affiliation: Diagnostic Laboratory for Infectious Diseases and Perinatal Screening, National Institutes for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands.
authors.forename: Marion P G
authors.initials: MPG
authors.lastname: Koopmans
authors.affiliation: Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Mary K
authors.initials: MK
authors.lastname: Estes
mesh_terms: D000818:Animals; D017250:Caliciviridae Infections / Q000821:virology; D002460:Cell Line; D003588:Cytopathogenic Effect, Viral; D005243:Feces / Q000821:virology; D005759:Gastroenteritis / Q000821:virology; D006801:Humans; D007753:Laboratories; D029322:Norovirus / Q000145:classification / Q000235:genetics / Q000254:growth & development*; D014773:Virology / Q000379:methods*; D014776:Virus Cultivation