title: A diagnostic one-step real-time reverse transcription polymerase chain reaction method for accurate detection of influenza virus type A.
abstract: BACKGROUND
  Influenza A is known as a public health concern worldwide. In this study, a novel one-step real-time reverse transcription polymerase chain reaction (rtRT-PCR) assay was designed and optimized for the detection of influenza A viruses.
  
  
  METHODS
  The primers and probe were designed based on the analysis of 90 matrix nucleotide sequence data of influenza type A subtypes from the GenBank database of the National Center for Biotechnology Information (NCBI). The influenza virus A/Tehran/5652/2010 (H1N1 pdm09) was used as a reference. The rtRT-PCR assay was optimized, compared with that of the World Health Organization (WHO), and its analytical sensitivity, specificity and reproducibility were evaluated. In total, 64 nasopharyngeal swabs from patients with influenza-like illness (ILI) and 41 samples without ILI symptoms were tested for the virus, using conventional cell culture, direct immunofluorescence antibody (DFA) methods, and one-step rtRT-PCR with the designed primer set and probe and the WHO's.
  
  
  RESULTS
  The optimized assay results were similar to the WHO's. The optimized assay results were similar to WHO's, with non-significant differences for 10-103copies of viral RNA/reaction (p> 0.05). It detected 10 copies of viral RNA/reaction with high reproducibility and no cross reactivity with other respiratory viruses. A specific cytopathic effect was observed in 6/64 (9.37%) of the ILI group using conventional culture and DFA staining methods; however, it was not seen in non-ILI. Also, the results of our assay and the WHO's were similar to those of viral isolation and DFA staining.
  
  
  CONCLUSIONS
  Given the high specificity, sensitivity and reproducibility of this novel assay, it can serve as a reliable diagnostic tool for the detection of influenza A viruses in clinical specimens and lab experiments.
authors.affiliation: Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Namazi Hospital, Shiraz, Iran; Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Mohammad Amin
authors.initials: MA
authors.lastname: Behzadi
authors.affiliation: Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Namazi Hospital, Shiraz, Iran.
authors.forename: Mazyar
authors.initials: M
authors.lastname: Ziyaeyan
authors.affiliation: Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Namazi Hospital, Shiraz, Iran.
authors.forename: Abdolvahab
authors.initials: A
authors.lastname: Alborzi
keywords: detection; influenza A virus; one-step real-time polymerase chain reaction