Genetic analysis of Puumala hantavirus strains from Austria

Sequences of the Small (S) and the Medium (M) genome segments of Puumala hantavirus (PUUV) were recovered from bank voles Clethrionomys glareolus trapped at 2 locations, Klippitztörl (Carinthia) and Ernstbrunn (Lower Austria). Lung tissue samples from 12 rodents earlier found hantavirus antibody-positive were further screened for the presence of hantaviral N-antigen using immunoblotting. RNA purified from 7 N-Ag-positive samples was subjected to the reverse transcription-polymerase chain reaction with primers designed to recover the complete S segment sequence of PUUV. The amplicons of expected size (approximately 1800 bp) have been recovered from 2 samples, 1 from Klippitztörl and another from Ernstbrunn. From the same 2 samples, PCR amplicons corresponding to the partial M segment sequence (nt 2140 to 2594), have been prepared. The S and M amplicons were sequenced and subjected to genetic analyses. Recovered hantavirus genome sequences undoubtedly belonged to PUUV genotype and the corresponding wild-type hantavirus strains were designated as PUU/Klippitztörl/Cg9/1995 and PUU/Ernstbrunn/Cg641/1995. Phylogenetic analysis placed 2 Austrian PUUV strains within a distinct genetic lineage that also included strains from the neighbouring Slovenia and Croatia. This Alpe-Adrian lineage, previously designated as 'Balkan lineage', was well supported on both S and M phylogenetic trees.