ABSTRACT
Objective To analyze the viral genetic characteristics of hantaviruses carried by Microtus maximowixzii in Yakeshi of Inner Mongolia Autonomous Region and its relationship with Hantaan virus (HTNV) and Seoul virus (SEOV) viruses as well as to identify the natural host of Khabarovsk virus (KHAV).Methods HV specific RNAs were detected by RT-PCR.Complete S and M segment were amplified from the RNA-positive samples.Phylogenetic analysis were performed to estimate the genetic characterization and the relationship with other hantaviruses.Results Fifty two Microtus maximowixzii voles were captured in Yakeshi areas.Of those voles,hanta-viral RNA was tested positive in 5 samples (9.62％).Complete S and M segments sequences were obtained from 5 and 2 lung samples,respectively.The complete S segment was consisted of 1848 to 1861 bp,and the M segment consisted of 3662 bp.These viruses were closely related to each other with 92.5％-96.4％ for the S segment sequences and 88.9％-95.4％ for the M segment sequences.They shared a higher identity with KHAV found previously in Yakeshi and KHAV of Russia.However,they were obviously different from the other hantavirus species.The 5 strains had the consistent secondary structure of nucleocapsid protein (NP) and glycoprotein (GP).When further comparing their secondary structures with those of HTNV and SEOV,our results indicated that there were no obvious differences in NP between KHAV and both HNTV,SEOV but with obvious difference in GP.Based on the S and M segment sequences,phylogenetic analyses revealed that these 5 strains clustered together with KHAV and formed a distinct lineage.Furthermore,all known KHAV strains could be divided into two small branches with a nucleotide divergence more than 5.3％.Conclusion Our research data revealed that KHAV was highly endemic among Microtus maximowixzii in Yakeshi area which supported the notion that Microtus maximowixzii had been the natural host of KHAV in the area.