A duplex SYBR green I-based real-time polymerase chain reaction assay for concurrent detection of feline parvovirus and feline coronavirus

Feline coronavirus (FCoV) contains two serotypes, feline enteric coronavirus (FECV) and Feline infectious peritonitis virus (FIPV). FECV and feline parvovirus (FPV) can cause similar clinical symptoms in cats, such as diarrhea. The objective of this study was to establish a duplex SYBR Green I-based quantitative polymerase chain reaction (qPCR) assay for rapid and simultaneous detection of FPV and FCoV. Two pairs of specific PCR primers were designed to target fragments of the VP2 gene of FPV and of the 5′ UTR gene of FCoV, respectively. The assay distinguished between the two viruses based on the melting curves (melting temperatures 77.0 ± 0.5 °C [FPV] and 80.5 ± 0.5 °C [FCoV]). The minimum limits of FPV and FCoV detection were 4.74 × 101 copies/μL and 7.77 × 101 copies/μL, respectively. The assay showed excellent reproducibility and reliability, based on the mean coefficient of variation. In conclusion, this novel duplex SYBR Green I-based qPCR assay is sensitive and can specifically, reliably, and rapidly detect FPV and FCoV (co-)infections.