| heterogeneity in nsp2 of european-like porcine reproductive and respiratory syndrome viruses isolated in the united states. | recently, isolates of porcine reproductive and respiratory syndrome virus (prrsv) that possess nucleotide sequences similar to european isolates have been reported in united states herds. the origin, diversity and prevalence of european-like north american prrsv isolates in the u.s. remain unknown. nucleotide sequence analysis of the 12kb orf1 of a north american isolate, sdprrs 01-08 (01-08), showed 93.7% identity with lelystad virus (lv), the prototypic european isolate, but only 58% identity ... | 2004 | 15019241 |