A duplex TaqMan probe-based real-time PCR assay for simultaneous detection of Psittacine beak and feather disease virus and Aves polyomavirus 1 from psittacine birds in Korea

Psittacine beak and feather disease virus (PBFDV) and Aves polyomavirus 1 (APyV) are important viral pathogens in psittacine birds worldwide.Early diagnosis and isolation of infected birds are key to preventing the transmission of these viruses to healthy birds.In this study, a TaqMan probe-based duplex real-time quantitative polymerase chain reaction (dqPCR) assay was developed for the rapid and differential detection PBFDV and APyV.The developed dqPCR assay using two sets of primers and probes specifically amplified the PBFDV V1 gene and APyV T gene in a single reaction.The limit of detection of the assay was determined to be below 50 copies for the corresponding target gene of PBFDV or APyV, which were lower than that of previous conventional PCR (cPCR) for PBFDV and comparable to that of previous cPCR for APyV.In the clinical evaluation, the diagnostic sensitivity of the new dqPCR assay for PBFDV or APyV was 55.2% (48/87) or 13.8% (12/87), which was higher than that of previous PBFDV cPCR (35.6%, 31/87) or consistent with that of previous APyV cPCR (13.8%, 12/87), respectively.The coinfection rate of PBFDV and APyV was 12.6% (11/87) in the psittacine clinical samples tested, which was higher than the rates reported in Chile, Bangladesh, and Brazil, but similar to the rates reported in Taiwan and Eastern Turkey.These results will be helpful to expand our knowledge on epidemiology of PBFDV and APyV infections in Korea.Conclusively, the developed dqPCR assay was found to be an accurate and reliable diagnostic tool for PBFDV and APyV in clinical samples of psittacine birds and will be useful for etiological and epidemiological studies and the control of the virus infections in the field.