Résumé
Objective To identify the biological and molecular biological characteristics of SN7 virus isolated from Niviventer Confucianus in Sichuan province. Methods Monoclonal antibody, PRNT and PCR antigenicity analysis and genotyping of SN7 strain were performed. M and S segments of SN7 genome were also cloned and sequenced. The sequences were compared with those of other strains of Hantavirus. Results It was difficult to identify SN7 by using monocloncal antibody, PRNT and PCR. With sequence comparison, we found that strain SN7 had high homology(80.2%～87.1% of M segment and 76.6%～92.0% of S segment) with HTN type strains, and relatively low homology(70.0%～71.6% of M segment and 71.0%～72.2% of S segment) with SEO type strains. Strain SN7 was believed to belong to HTN type. Conclusions SN7 is a new subtype strain of HTN type viruses. It is possible that Hantavirus has immune escape in its natural hosts.
Résumé
Objective To understand the species diversity of ectoparasites on Niviventer confucianus in the surrounding areas of Erhai Lake.Methods Small mammals were randomly captured in 12 investigated sites surrounding Erhai Lake with baited mouse cages.The cage-traps were examined and re-baited each morning.Trapped small mammals were brought to the laboratory for identification according to color, body length, ear length, hind foot length.All ec-toparasites on the surface of the hosts were collected and identified.The constituent ratio(C), prevalence(P) and average ectoparasite abundance(A) were used to evaluate the prevalence and density of ectoparasites.Non-parametric Mann-Whitney U-test was used to test differences in the abundance and richness of ectoparasites between female and male hosts.Spearman correlation analysis was used to analyze the relationship between ectoparasites and the body param-eters of hosts.Results Eighty-nine individuals of N.confucianus were captured, of which 79% were found infested with 51 species of ectoparasites, including 31 species of chigger mites, 13 species of mesostigmatid(gamasid) mites, 4 species of fleas and 3 species of sucking lice.Walchia ewingi Fuller(66.2%), Laelaps turkestanicus Lange(38.5%), Paradoxopsyllus custodies Jordan(42.9% ) and Hoplopleura pacifica(80.1% ) were the most predominant species of chigger mites, gamasid mites, fleas, and sucking lice, respectively.Non-parametric Mann-Whitney U-test showed that there was no significant difference between male and female hosts on the species richness and abundance of total ec-toparasites, chigger mites, sucking lice, fleas or gamasid mites.Spearman correlation analysis showed that the abun-dance and species of total ectoparasites, chigger mites, sucking lice, fleas or gamasid mites were not correlated with the body weight of hosts.Conclusion There is a high speices diversity of ectoparasites on N.confucianus.Sucking lice, fleas, chiggers and gamasid mites are the main ectoparasites.