title: TaqMan real-time reverse transcription-PCR assay for universal detection and quantification of avian hepatitis E virus from clinical samples in the presence of a heterologous internal control RNA.
abstract: Avian hepatitis E virus (HEV) isolates could be separated into at least three genotypes. In this study, the development of the first duplex TaqMan real-time reverse transcription-PCR (RT-PCR) assay for detection and quantification of avian HEV is presented. Primers and probes binding within relatively conserved open reading frame 3 (ORF3) were designed. Tenfold dilution series of in vitro-transcribed avian HEV RNA were used as the standard for quantification. A 712-bp region of the green fluorescent protein gene was transcribed in vitro and used as a heterologous internal control for both RNA isolation and real-time RT-PCR. The duplex real-time RT-PCR for avian HEV had an efficiency of 1.04, a regression squared value of 0.996, and a sensitivity of approximately 3.6 × 10(3) copies per reaction mixture when in vitro-transcribed RNA was used as the template. The presence of in vitro-transcribed heterologous internal control RNA did not affect amplification of avian HEV RNA compared to that achieved by the single assay. The sensitivity of the real-time RT-PCR assay was comparable to that of conventional RT-PCR, and it was shown to be highly specific, as tissues from uninfected chickens, mammalian HEVs, and other viral genomes did not produce positive signals. All tested field samples with virus belonging to different avian HEV genotypes were successfully detected with this new duplex TaqMan real-time RT-PCR assay.
authors.affiliation: Clinic for Avian, Reptile and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria.
authors.forename: Salome
authors.initials: S
authors.lastname: Troxler
authors.forename: Ana
authors.initials: A
authors.lastname: Marek
authors.forename: Irina
authors.initials: I
authors.lastname: Prokofieva
authors.forename: Ivana
authors.initials: I
authors.lastname: Bilic
authors.forename: Michael
authors.initials: M
authors.lastname: Hess
mesh_terms: D000818:Animals; D002645:Chickens; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D006524:Hepatitis, Viral, Animal / Q000175:diagnosis* / Q000821:virology*; D052678:Hepevirus / Q000235:genetics / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes / Q000235:genetics; D011201:Poultry Diseases / Q000175:diagnosis / Q000821:virology; D012327:RNA Virus Infections / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D012367:RNA, Viral; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods* / Q000592:standards; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000235:genetics; D014773:Virology / Q000379:methods* / Q000592:standards
chemical_list: D017931:DNA Primers; C400973:ORF3 protein, Hepatitis E virus; D015345:Oligonucleotide Probes; D012367:RNA, Viral; D014764:Viral Proteins