Remarkable cross-reaction of pan-pestivirus PCR primers with poliovirus genome

When several human vaccines were tested for pestivirus contamination using a one-tube closed nested RT-PCR method employing pan-pestivirus primers selected from the 5'-untranslated region (5'-UTR) of the pestivirus genome, a 224 bp DNA product was produced from a poliovirus vaccine. Although this amplicon was of the size expected for pestiviruses, its sequence showed a 100% similarity with the corresponding reverse complement of a nucleotide sequence from the VP2 gene of the poliovirus type 1 Sabin strain. It is recommended that all positive PCR products, especially those prepared using pan-pestivirus primers, obtained from screening biological substances for pestivirus contamination should be checked by use of a specific hybridization probe and preferably by sequencing.