Real-time reverse transcription PCR-based sequencing-independent pathotyping of Eurasian avian influenza A viruses of subtype H7

Virol J. 2017 Jul 24;14(1):137. doi: 10.1186/s12985-017-0808-3.

Abstract

Low pathogenic avian influenza viruses (LPAIV) of the subtypes H5 and H7 are known to give rise to highly pathogenic (HP) phenotypes by spontaneous insertional mutations which convert a monobasic trypsin-sensitive endoproteolytical cleavage site (CS) within the hemagglutinin (HA) protein into a polybasic subtilisin-sensitive one. Sporadic outbreaks of notifiable LPAIV H7 infections are continuously recorded in Europe and in Asia, and some lineages showed zoonotic transmission. De novo generation of HPAIV H7 from LPAIV precursors has been reported several times over the past decade. Rapid differentiation between LP and HP H7 virus strains is required as a prerequisite to emplace appropriate control measures. Here, reverse transcription real-time PCR assays (RT-qPCR) were developed and evaluated that allow LP and HP pathotype identification and distinction by probe-assisted detection of the HACS. These new RT-qPCRs allow a sensitive and highly specific pathotype identification of Eurasian subtype H7 AIV in allantoic fluids as well as in diagnostic field samples. RT-qPCR assisted pathotyping presents a rapid and sensitive alternative to pathotyping by animal inoculation or nucleotide sequencing.

Keywords: Avian influenza; Cleavage site; Diagnosis; Hemagglutinin subtype H7; Pathotyping; Real-time RT-PCR.

Publication types

  • Evaluation Study

MeSH terms

  • Animals
  • Asia
  • Birds
  • Europe
  • Genotype*
  • Genotyping Techniques / methods*
  • Influenza A virus / classification*
  • Influenza A virus / genetics*
  • Influenza A virus / isolation & purification
  • Influenza A virus / pathogenicity
  • Influenza in Birds / virology*
  • Real-Time Polymerase Chain Reaction / methods*
  • Reverse Transcriptase Polymerase Chain Reaction / methods*
  • Sensitivity and Specificity