Identification of enteroviruses isolated from sea-water: indirect immunofluorescence (IIF)

In this research the Enteroviruses presence in sea water was studied. In previous studies presumptive Enteroviruses were revealed in 43% and in 77% of sea water samples analyzed. It was necessary to identify viral particles isolated from marine water because the detection of this kind of virus was performed only on the basis of cytopathic effect appearance on cell cultures. The aim of this research was to verify the suitability of Indirect Immunofluorescence for identification of presumptive Enteroviruses isolated from marine waters. 13 field strains from RC 37 cells (Cercopithecus Kidney cell line) were tested. Pools of Horse immune sera against COXS, POLIO and ECHO, and anti-horse antibodies conjugated with fluorescein were used. The results revealed the presence of Coxsackie virus and Echo virus. There were many problems related with ECHO identification for the presence of cross-reactions with COXS. The IIF method cannot be performed routinely, because it did not show high level of specificity and sensibility, and it is expensive. This methodology can be used only in particular cases and in laboratories with competent virologists and related facilities. In the future, the only suitable methodology for identification of Enteroviruses isolated from field samples is based on the use of RNA and DNA probes.