title: Occurrence of mixed populations of influenza A viruses that can be maintained through transmission in a single host and potential for reassortment.
abstract: Reassortment, which is the rearrangement of viral gene segments in a host cell infected with two different viruses, is an important mechanism for the evolution of influenza viruses. Mixed infections with multiple virus types could lead to reassortment. To better understand the occurrence of quasispecies in a single host, we investigated mixed infections in individual isolates of seasonal influenza A viruses using amantadine sensitivity as a marker. We cultured viruses with amantadine and performed sequencing, restriction fragment length polymorphism analysis, cloning, and quantitative PCR to detect mixed populations. Culturing with amantadine showed evidence of a high number of mixed populations, while the other assays could hardly detect mixed populations. The existence of quasispecies in each isolate was common. However, the proportion of these, which can be less than 1%, is too low to be detected by conventional methods. Such mixed populations in which reassortment occurs may have a significant role in the evolution of viruses.
authors: Department of Virology, Tohoku University, Graduate School of Medicine, 2-1 Seiryou-machi, Aoba-ku, Sendai, 980-8575, Japan.
authors: Yuki
authors: Y
authors: Furuse
authors: Akira
authors: A
authors: Suzuki
authors: Makiko
authors: M
authors: Kishi
authors: Nao
authors: N
authors: Nukiwa
authors: Midori
authors: M
authors: Shimizu
authors: Rumi
authors: R
authors: Sawayama
authors: Naoko
authors: N
authors: Fuji
authors: Hitoshi
authors: H
authors: Oshitani
mesh_terms: D000547:Amantadine / Q000494:pharmacology; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology; D002460:Cell Line; D003001:Cloning, Molecular; D016172:DNA Fingerprinting; D004285:Dogs; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D053122:Influenza A Virus, H3N2 Subtype / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D007251:Influenza, Human / Q000821:virology*; D008969:Molecular Sequence Data; D009305:Nasopharynx / Q000821:virology*; D012150:Polymorphism, Restriction Fragment Length; D012367:RNA, Viral / Q000235:genetics; D016865:Reassortant Viruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D017422:Sequence Analysis, DNA; D014776:Virus Cultivation / Q000379:methods
chemical_list: D000998:Antiviral Agents; D012367:RNA, Viral; D000547:Amantadine