Specific detection of echoviruses 22 and 23 in cell culture supernatants by RT-PCR.

Reverse transcription-polymerase chain reaction (RT-PCR) methods are available for the rapid detection of enteroviruses in clinical specimens or virus isolates. Pan-enterovirus PCR primers, however, fail to amplify echovirus (E) type 22 or 23 because of their extreme sequence divergence from the other enteroviruses. We have developed an RT-PCR method to detect specifically E22 and E23 RNA directly in tissue culture supernatants without a viral RNA purification step. The E22/E23 primers successfully amplified 20 of 20 clinical isolates of E22 and 4 of 4 E23 isolates representing viruses isolated in 15 states over a 19-year period, as well as E22 and E23 prototype strains isolated in the 1950s. The primers did not amplify any of the other 64 enterovirus prototype strains.