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Complexities of Viral Nomenclature

Explore the complex system of viral nomenclature, where viruses are named based on associated diseases, disease types, body sites, geographic locations, discoverers, and more. Learn about the International Committee on Taxonomy of Viruses (ICTV) and the Baltimore System of virus classification.

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Complexities of Viral Nomenclature

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  1. Complexities of Viral Nomenclature No consistent system for naming viruses – some are named for the: • associated diseases (e.g. poliovirus, rabies virus) • specific type of disease they cause (e.g. hepatitis A,B,C, D, E) • sites in the body that are affected or from which they were first isolated (e. g. rhinovirus and adenovirus) • geographic locations in which they were first isolated (e.g. Sendai virus [Sendai, Japan] and Coxsackievirus[Coxsackie, New york]) • sicentistswho first discovered them (e.g. Epstein-Barr virus) • way in which people imagined they were contracted (e.g. dengue, for “evil spirit” and influenza, for the “influence of bad air) • combinations (e.g. Rous sarcoma virus)

  2. International Committee on Taxonomy of Viruses (ICTV) • member group of the International Union of Microbiological Societies • oversees the ongoing process of devising and maintaining a universal classification scheme for viruses • Assigns viruses to orders, families, subfamilies, genera, and species based on information provided by study groups composed of experts on specific types of viruses.

  3. David Baltimore developed a system to classify viruses based on their genomes…The Baltimore System… dsDNA ssDNA dsRNA ss (+) RNA ss (-) RNA ss (+) RNA with DNA intermediate gapped dsDNA VII

  4. Virus Classification Classical hierarchical system: Kingdom Phylum Class Order - virales Family (-viridae) Genus (-virus) Species (73) (287)

  5. Virus Classification • Order: virales • Family: Filoviridae • Enveloped virions, variably elongated filaments 650–1,400 nm in length and pleomorphic in shape, containing a helical nucleocapsid with single-stranded negative-sense RNA (about 19 kilobases in length) and an endogenous RNA polymerase. • Genera: • Filovirus : contains the Marburg viruses • Ebolavirus:contains the Ebola viruses. • Species (Strain): • Ebolavirus: Ebola-Zaire, Ebola-Sudan, Ebola-Cote d’Ivoire, Ebola-Reston, Ebola-Bundibugyo

  6. DNA Virus Mnemonic "HHAPPPPy", -Hepadna -Herpes -Adeno -Pox -Parvo -Papilloma -Polyoma All DNA viruses except the Parvoviridae are dsDNA Extremely stable, resistant to heat, detergents and chlorination

  7. All RNA viruses except Reoviridae are ssRNA

  8. A27y/o workeratadaycarecenter hasrecentlybeenfeelingtired,hasaslightfever,andhasfeltnauseatedandvomitedseveraltimes.Yesterday,shehadabdominalpainandchills,andtodayshevoideddarkurine.LabtestsforserumenzymesindicatedelevatedASTandALT.Noinfectiousagentcouldbegrowninculture,butPCRtestingdeterminedthatthecausativeagentcontainsapositivesense,Single StrandedRNAgenome.Electronmicroscopyrevealedanakedicosahedralcapsidapproximately28nmindiameter.Thevirusresponsiblefortheinfectionbelongstothefamily: Hepadnaviridae Flaviviridae Picornaviridae Polyomaviridae

  9. A27y/o workeratadaycarecenter hasrecentlybeenfeelingtired,hasaslightfever,andhasfeltnauseatedandvomitedseveraltimes.Yesterday,shehadabdominalpainandchills,andtodayshevoideddarkurine.LabtestsforserumenzymesindicatedelevatedASTandALT.Noinfectiousagentcouldbegrowninculture,butPCRtestingdeterminedthatthecausativeagentcontainsa positive sense, Single Stranded RNA genome.Electronmicroscopyrevealed a naked icosahedral capsid approximately 28 nm indiameter.Thevirusresponsiblefortheinfectionbelongstothefamily: Hepadnaviridae Flaviviridae Picornaviridae Polyomaviridae

  10. Which of the following statements is correct? • Viruses can have an icosahedral capsid or an envelope, but not both. • Helical capsids are always surrounded by an envelope. • Icosahedral capsids are only found among DNA viruses. • Icosahedral capsids are very large.

  11. Which of the following statements about human viruses is correct? • Viruses can have an icosahedral capsid or an envelope, but not both. • Helical capsids are always surrounded by an envelope. • Icosahedral capsids are only found among DNA viruses. • Icosahedral capsids are very large.

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