Evaluation of seroneutralization and molecular diagnostic methods for echovirus identification

In this study we compared the identification results of 41 echovirus clinical isolates using RIVM pools (National Institute for Public Health and the Environment RIVM, Bilthoven, The Netherlands) and reverse transcription-polymerase chain reaction (PCR) assays. Primer pair UG52-UC53 amplified a 433-bp segment in the 5′ untranslated region. Restriction enzyme HpaII was used for subgrouping of our isolates into 2 different genetic clusters. Amplification of 315 bp that is located in 5′ end of VP1 gene as well as of a long genomic fragment (1452 bp) including the VP1 3′ end, the entire coding sequence of 2A, 2B, and the 5′ moiety of the 2C-coding region was achieved by the application of PCR protocols with primers 292-222 and EUG2a, 2b, 2c-EUC2, respectively. Phylogenetic trees were constructed for the 5′ end as well as for the 3′ end of VP1 gene using nucleotide sequences derived from sequencing of clinical isolates and homologous sequences of all echovirus serotypes. The phylogenetic grouping pattern of the clinical isolates revealed a correlation of serotype and genotype either in the 5′ or in the 3′ end of the VP1 gene that was investigated in the present study claiming that they can be either used for molecular typing of echoviruses.