Establishment and Application of a Taqman Reverse Transcriptase Quantitative Real Time Pcr Assay for Feline Calicivirus

Abstract Feline calicivirus (FCV) is an infectious pathogen that causes disease in cats. With the current emergence of FCV-associated virulent systemic disease (FCV VSD) worldwide, the establishment of a rapid, sensitive, and reproducible diagnostic assay for its detection is important to inform prevention and control strategies. In this study, specific primers and TaqMan-FAM probes were designed based on the conserved regions of the FCV genome sequence, and a TaqMan reverse transcriptase quantitative real time PCR assay was established. This assay could specifically detected the FCV genome. The assay had a wide dynamic range, with linear detection in the range of 9.6×109 copies/μL to 9.6×100 copies/μL, with a limit of detection of 9.6×100 copies/μL, showing high sensitivity and repeatability. In addition, we used this assay to evaluated clinical samples (n=100) taken from cats from across China for the presence/absence of FCV genetic material For samples with low virus content, the positive detection rate of TaqMan reverse transcriptase quantitative real time PCR assay (RT-qPCR) was much higher than that of conventional reverse transcriptase PCR assay (cRT-PCR). And The qRT-PCR assay was used to detect the viral load of cat swabs within 17 days after FCV infection. From days 1-9, the oral and nasal swabs generally had higher viral loads than the anal swabs. While from days 10-17, the levels in the oral and nasal swabs being generally lower than those in the anal swabs. Overall, this FCV TaqMan RT-qPCR assay assay represents a rapid and accurate.