Identification, phenotypic analysis, and full-length nucleotide sequence of a Dutch Coxsackievirus A20 isolate

Recombination between (human) enteroviruses is a common event in nature. Recently, it has been recognised that this feature has a major impact on the use of the live-attenuated polio vaccine during the end stage of polio eradication. The constraints for successful recombination between (vaccine-derived) polioviruses and human enteroviruses are, however, largely unknown. Here, we describe the identification and characterisation of a HEV-C field strain, isolated from the stool of a 2-year-old Dutch boy. Serotyping indicated that strain 89490 is a variant of strain CAV20a, which is already a variant of the prototype CAV20 strain. Amino acid sequence identity of 94.1% for the entire P1-region, and 92.4% for the major structural protein (VP1) indicates that this strain is indeed related to CAV20. However, virus neutralisation and Western blot analysis failed to show antigenic homology between the prototype CAV20 strain and our field strain. Furthermore, the 89490 field strain, just like the sub-prototype CAV20a, is able to replicate on RD-cells, while the prototype CAV20 and another sub-prototype CAV20b are not. On the basis of the phylogenetic analysis of the P2 and P3 region we expect that strain 89490 can act as recombination partner for the attenuated poliovirus strains of the Oral Polio Vaccine (OPV).