Genetic variation in Tula hantaviruses: sequence analysis of the S and M segments of strains from Central Europe.

Hantavirus carried by the European common vole Microtus arvalis from Moravia (Czech Republic) was analyzed by RT-PCR-sequencing and by reactivity with a panel of monoclonal antibodies (MAbs). Sequencing of the full-length S segment and the proximal part of the M segment showed that the virus belonged to genotype Tula (TUL) we discovered earlier in Microtus arvalis from Central Russia. This finding supported the concept of host dependence of hantaviruses. Phylogenetic analyses suggested a similar evolutionary history for S and M genes of TUL strains; thus far there is no evidence for reassortment in TUL. Geographic clustering of TUL genetic variants was observed and different levels of the genetic variability were revealed resembling those estimated for another hantavirus, Puumala (PUU). Comparison of the deduced N protein sequence from Russia and from Moravia showed that genetic drift in TUL occurred not only by accumulation of point mutations but also by the deletion of a nucleotide triplet. It encoded Ser252 which was located within a highly variable hydrophilic part of the N protein carrying B-cell epitopes and presumably forming a loop. Analysis of naturally expressed TUL N-antigen derived from lung tissue of infected voles with MAbs indicated antigenic heterogeneity among TUL strains.

[Prevalence of hantavirus infection in small mammals in the South Moravian Region]. / Prevalence nákaz drobných savcu hantaviry v Jihomoravském kraji.

In 1987 to 1990 in the South Moravian region 1094 lungs of small terrestrial mammals were examined for hantavirus antigen and sera of 525 rodents and 93 hares for antibodies against these viruses. In the majority the materials were not from the same individual. Lungs were examined by the ELISA method, antibodies were assessed by the indirect immunofluorescence reaction. An antigen resembling the western subtype (Puumala) was found in 65 animals (5.9%) of two rodent species (Microtus arvalis--63 times and Apodemus flavicollis--twice) in 20 localities. Antibodies against this subtype were detected in 25 examined individuals (4.0%) of four species (Microtus arvalis, Apodemus flavicollis, Pitymys subterraneus and Lepus europaeus) from eight localities. A marked predominance of positive findings was obtained from Microtus arvalis which under conditions of the South Moravian region can be considered the main host of hantaviruses of the western subtype. Only in one specimen of Clethrionomys glareolus from Hrbov antibodies against the eastern subtype were detected (Hantaan). Hantaviruses form in Southern Moravia natural foci of the avector type, in particular in perennial fodder crops, most frequently with a mesophil character of the site. The foci were found most frequently at sites of assumed borderlines of natural meadow forests of the Alno-Padion type and woods of the Carpinion betuli, Quercion robori-petreae and Fagion silvaticae type.