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.

Epidemiological Surveillance of Low Pathogenic Avian Influenza Virus (LPAIV) from Poultry in Guangxi Province, Southern China

“…Mixed infections with multiple virus types could lead to reassortment [20], [27]. In addition, concomitant infections of the fungal pathogen Cryptococcus neoformans may be associated with enhanced virulence [28].…”

Rapid Differentiation of Mixed Influenza A/H1N1 Virus Infections with Seasonal and Pandemic Variants by Multitemperature Single-Stranded Conformational Polymorphism Analysis

“…This genetic property of the virus allows genes to be exchanged between two (or more) genetic variants separately from the rest of the genome. The process, known as reassortment, can lead to abrupt changes in the genetic pool of the virus and may contribute to the emergence of new viral subtypes with pandemic potential (5).…”

Antigenic Analyses of Highly Pathogenic Avian Influenza A Viruses

“…A more comprehensive understanding of the antigenic relationships within and between different viruses generally relies on polyclonal antisera. Regardless of the approach, it should be noted that detailed sequence analysis of all viruses used for laboratory assays or to generate antisera is essential to detect mixed virus populations; as the literature is replete with examples of antigenic differences due to mixed sequence populations (Deyde et al 2009;Furuse et al 2010;Ghedin et al 2011;Hay et al 2001;Ramakrishnan et al 2009;Robertson et al 1994).…”