Direct detection of polioviruses using a recombinant poliovirus receptor

Polioviruses are positive-sense, single-stranded RNA picornaviruses and the principal cause of poliomyelitis. Global poliovirus surveillance has relied on poliovirus isolation in cells, which may take a minimum of 10 days, involves maintaining two cell lines, and propagates virus in high titers. With eradication underway, a major objective of the Global Polio Eradication Initiative (GPEI) is to develop culture-independent detection of polioviruses as an alternative method to complement the current virus isolation technique. A culture-independent method on poliovirus-positive stool suspensions was assessed with commercially available recombinant soluble poliovirus receptor (PVR) coupled to Histidine (His) tags. Viral RNA was screened by quantitative real-time reverse transcription PCR using the poliovirus intratypic differentiation kit. Poliovirus recovery was optimized with PVR-His-tagged protein and buffers supplemented with polyethylene glycol. To validate the poliovirus-PVR-His tag purification assay, 182 poliovirus-positive stools of programmatic importance were parallel tested against the GPLN-accepted virus isolation method. The PVR-His tag enrichment method detected poliovirus in 164 of 171 poliovirus-positive stools, whereas the virus isolation method misidentified 38 stools as poliovirus-negative (McNemar χ2 p