Sequence variability and evolutionary trends of the H gene of Canine Distemper virus (CDV) from Uruguay

YANINA PANZERA; NICOLAS SARUTE; MARINA GALLO CALDERON; LA TORRE, JOSE; ARIANNE CARDEILLAC; SOLEDAD GUASCO; MARTÍN HERNÁNDEZ; LOURDES FRANCIA; RUBEN PEREZ

Punta del Este: Maldonado : Uruguay (Barradas Hotel)

Conferencia; 150 years of Darwin's Evolutionary Theory: a South American celebration; 2009

Canine distemper virus (CDV) (Paramyxoviridae, Morbillivirus) causes one of the most severe infectious diseases in wild and domestic dogs and many other carnivorous species. As a single strand RNA virus, CDV replication is error prone and cause genetic variation and antigenic drift at high frequency. This is particularly reflected in the hemagluttinin (H) gene that encodes the major antigenic viral protein. The pronounced genetic diversity of the H gene found in the CDV outbreaks have made possible to establish phylogenetic relationships among the worldwide circulating strains. Most CDV strains cluster into seven major genetic lineages with distinctive geographic patterns, which are designated as America-1, America-2, Asia-1, Asia-2, Europe, Europe-wildlife and Arctic like. In order to analyze CDV genetic diversity and its evolutionary significance, we obtained the first full-length sequences of the H gene from Argentine and Uruguay field isolates and compared them with those of isolates from around the world. Phylogenetic analysis supports the existence of two different CDV genotypes or lineages circulating in South America. One genotype is represented by strains from Argentine, Brazil and Uruguay. It appears closely related with European strains (Europe lineage), probably as a consequence of either shared ancestry or more recent events of gene flow due to the movement of animals between some European countries and South America. Another lineage or genotype, represented only by Argentinean strains, seems to be exclusive for South America and it likely represents an ancestral lineage. Our analysis reveals the heterogeneity of South American CDV and it also supports the existence of geographic patterns in the distribution of most strains. Furthermore, indicates that certain genotypes may also reflect connections between countries that keep important cultural and commercial relationships