Genetic diversity of the Junin virus in Argentina: Geographic and temporalpatterns

RNA was purified from 39 strains of cell-cultured Junin virus (JUN) from ce ntral Argentina, which included both human- and rodent-derived isolates (a total of 26 and 13, respectively), as well as from 2 laboratory JUN strains , XJ CI3 and XJ #44. JUN-specific primers were used to amplify a 511-nucleo tide (nt) fragment of the nucleocapsid protein gene and a 495-nt fragment o f the glycoprotein 1 (GP1) gene. Genetic diversity among JUN strains studie d was up to 13% at the nt lever and up to 9% at the amino acid (aa) level f or the GP1 gene and up to 9% (nt) and 4% (aa) for the NP gene. Phylogenetic analyses of both genes revealed three distinct clades. The first clade was composed of the JUN strains from the center of the endemic area and includ ed the majority of JUN strains analyzed in the current study. The second cl ade contained 4 JUN strains isolated between 1963 and 1971 from Cordoba Pro vince, the western-most edge of the known endemic area. The third clade con tained 4 JUN strains that originated from Calomys musculinus trapped in Zar ate, the northeastern edge of the known endemic area. Certain JUN sequences , which were obtained from GenBank and identified as XJ, XJ #44, and Candid #1 strains, appeared to form a separate clade. Over 400 nt of the GP1 and GP2 genes were additionally sequenced for 7 JUN strains derived from patien ts with different clinical presentations and outcomes of Argentine hemorrha gic fever. Analysis of the corresponding aa sequences did not allow us to a ttribute any particular genetic marker to the changing severity or clinical farm of the human disease. (C) 2000 Academic Press.