Development of a novel one-step triplex PCR assay for the simultaneous detection of porcine circovirus type 2, porcine parvovirus and classical swine fever virus in a single tube.

Co-infection of multiple pathogens complicates diagnosis, treatment and preventive measures based on clinical signs. Therefore, reliable diagnostic tool for timely reporting of suspected diseases is very much essential. A novel one-step triplex PCR assay was developed and evaluated for simultaneous detection of three important viruses namely porcine circovirus type 2 (PCV2), porcine parvovirus (PPV) and classical swine fever virus (CSFV) involved in reproductive problems in pigs. Each of the three pairs of oligonucleotide primers exclusively amplified the targeted fragment of the specific viruses. The multiplex PCR assay was found to be sensitive in detecting at least 300 pg of viral genomic DNA or RNA from a mixture of three viruses in a reaction. No amplification was obtained from other common viruses or pathogens, such as porcine reproductive and respiratory syndrome virus (PRRSV), Japanese encephalitis virus (JEV), porcine group A rotavirus (PoRVA), Escherichia coli and Staphylococcus aureus thereby indicating that the developed multiplex PCR has high specificity. Because of the sensitivity and specificity, the developed multiplex PCR assay will be a useful tool for clinical diagnosis of mixed infections of DNA and RNA viruses in pigs.