Co-circulation of distinct shrew-borne hantaviruses in the far east of Russia.

Insectivores are the new emerging reservoir of hantaviruses. Here, we describe Lena virus (LENV), a novel hantavirus harbored by the Laxmann`s shrew (Sorex caecutiens), which is also the host of Artybash virus (ARTV). Genetic analysis of the complete genomic sequence shows that LENV is in distant relation to ARTV and other Sorex-borne hantaviruses, suggesting that LENV has emerged from cross-species transmission. Additionally, new genetic variant of ARTV, designated as ARTV-St, was identified in tundra shrews (Sorex tundrensis). Finally, distinct insectivore-borne hantaviruses are co-circulating in the same localities of far eastern Russia: LENV, ARTV and Yakeshi in the forest site, while ARTV, ARTV-St, and Kenkeme virus in the meadow field site.

Tick-borne encephalitis virus in arthropod vectors in the Far East of Russia.

Isolates of tick-borne encephalitis virus (TBEV) from arthropod vectors (ticks and mosquitoes) in the Amur, the Jewish Autonomous and the Sakhalin regions as well as on the Khabarovsk territory of the Far East of Russia were studied. Different proportions of four main tick species of the family Ixodidae: Ixodes persulcatus P. Schulze, 1930; Haemaphysalis concinna Koch, 1844; Haemaphysalis japonica douglasi Nuttall et Warburton, 1915 and Dermacentor silvarum Olenev, 1932 were found in forests and near settlements. RT-PCR of TBEV RNA in adult ticks collected from vegetation in 1999-2014 revealed average infection rates of 7.9 ±â€¯0.7% in I. persulcatus, of 5.6 ±â€¯1.0% in H. concinna, of 2.0 ±â€¯2.0% in H. japonica, and of 1.3 ±â€¯1.3% in D. silvarum. Viral loads varied in a range from 102 to 109 TBEV genome-equivalents per a tick with the maximal values in I. persulcatus and H. japonica. Molecular typing using reverse transcription with subsequent real time PCR with subtype-specific fluorescent probes demonstrated that the Far Eastern (FE) subtype of TBEV predominated both in mono-infections and in mixed infection with the Siberian (Sib) subtype in I. persulcatus pools. TBEV strains of the FE subtype were isolated from I. persulcatus, H. concinna and from a pool of Aedes vexans mosquitoes. Ten TBEV strains isolated from I. persulcatus from the Khabarovsk territory and the Jewish Autonomous region between 1985 and 2013 cluster with the TBEV vaccine strain Sofjin of the FE subtype isolated from human brain in 1937. A TBEV strain from H. concinna collected in the Amur region (GenBank accession number KF880803) is similar to the vaccine strain 205 isolated in 1973 from I. persulcatus collected in the Jewish Autonomous region. The TBEV strain Lazo MP36 of the FE subtype isolated from a pool of A. vexans in the Khabarovsk territory in 2014 (KT001073) differs from strains isolated from 1) I. persulcatus (including the vaccine strain 205) and H. concinna; 2) mosquitoes [strain Malishevo (KJ744034) isolated in 1978 from Aedes vexans nipponii in the Khabarovsk territory]; and 3) human brain (including the vaccine strain Sofjin). Accordingly, in the far eastern natural foci, TBEV of the prevailing FE subtype has remained stable since 1937. Both Russian vaccines against TBE based on the FE strains (Sofjin and 205) are similar to the new viral isolates and might protect against infection.

Molecular evidence of Coxiella-like microorganism harbored by Haemaphysalis concinnae ticks in the Russian Far East.

Twenty female imago of Haemaphysalis concinnae ticks collected from wild vegetation in May of 2001 in the Obor region near Khabarovsk in the Russian Far East were studied. DNA was extracted with commercially available kits following manufacturer's instructions. We used broad range primers SFG3 and SFG6 proposed for amplification of 16S ribosomal RNA gene's portion of spotted fever group Rickettsia. Initial amplification resulted in positive results in all 20 ticks. Direct sequencing of five randomly chosen amplicons showed that obtained sequences belong to a new species. Closest homology was found in Coxiella burnetii 16S rDNA. Using the obtained sequence as a basis, we designed internal primers highly specific for that sequence. Then we confirmed our results by nested PCR amplification with newly designed primers Cox1 and Cox2-all 20 samples also were positive. Having combined these primers with universal eubacterial primers fD1 and rP2 we retrieved a 1,043 bp portion of the 16S rRNA gene. Consecutive homology search demonstrated that the closest sequence similarity belongs to new Coxiella sp. recently found in Rhipicephalus sanguineus ticks (95.2% of homology) and Coxiella burnetii (94% of homology). So, our results suggest that a novel Coxiella-like microorganism, provisionally called here "Cenerentola," is harbored by Haemaphysalis concinnae ticks in the Russian Far East.