NS1 gene based molecular characteristics of Aleutian mink disease virus circulating in Poland

The aim of this study was to characterise the genetic variability of the Aleutian mink disease virus (AMDV) circulating among mink farmed in Poland and to compare Polish isolates with AMDV variants available in the GenBank database. For this purpose PCR amplification and analysis of the 429 bp DNA fragment of the AMDV NS1 gene from 13 randomly selected AMDV infected mink was performed. A comparison showed that all tested amplicons were closely related to the sequence of the NS1 gene of AMDV and showed high (94%-97%) homology to virus variants from American mink (Neovison vison) isolated in Canada in 2007-2008. Eleven samples showing a high percentage (95%-97%) of sequence similarity together with three similar isolates originating from Canada formed one clade (monophyletic group). Two variants showing a lower percentage (about 94%- 95%) of sequence similarity to isolates from Canada formed a separate clade. Polish viruses can be subdivided into two main groups with a putative ancestor common to both Polish and three Canadian isolates. This result confirms the literature data indicating the occurrence of American mink in Eastern Europe (including Poland) from the 1950s when the animals were imported for breeding purposes. In conclusion, we provide for the first time a report on the genetic characteristics of the AMDV variants circulating in the Polish population of farmed mink and their relationship with previously known AMDV variants isolated and described abroad.