A TaqMan-based real-time PCR assay for the detection of Ungulate bocaparvovirus 2

Ungulate bocaparvoviruses (UBoV) 2-5 are recently discovered porcine bocaparvoviruses belonging to the family Parvoviridae, and are considered to be a potentially major cause of swine diseases. In order to detect local UBoV2 epidemics in China, we developed a TaqMan-based real-time PCR (qPCR) assay targeting the UBoV2 VP1 gene and compared the results of qPCR with conventional PCR (cPCR). The qPCR reproducibly detected a recombinant DNA plasmid containing the VP1 gene over a range of eight orders of magnitude, from 9.97 × 10−1-106 copies/μL, with a lower limit of detection of 9.97 copies/μL, compared with approximately 9.97 × 102 copies/μL for cPCR. The qPCR assay showed no cross-reactivity with other UBoVs or other porcine viruses. This qPCR assay detected UBoV2 in 18.1% (84/463) of pig samples collected from Chinese swine herds, with the highest infection rate of 35.3% (53/150) in loose stools. UBoV2 was not detected in liver samples. The TaqMan-based qPCR assay established in this study was highly sensitive and specific for the diagnosis and quantification of UBoV2. The results of this study will further our understanding of the etiology, epidemiology, and pathogenesis of UBoV2 infection.