Isolation, preliminary characterization, and full-genome analyses of tick-borne encephalitis virus from Mongolia

Abstract

Tick-borne encephalitis virus (TBEV) causes one of the most important inflammatory diseases of the central nervous system, namely severe encephalitis in Europe and Asia. Since the 1980s tick-borne encephalitis is known in Mongolia with increasing numbers of human cases reported during the last years. So far, however, data on TBEV strains are still sparse. We herein report the isolation of a TBEV strain from Ixodes persulcatus ticks collected in Mongolia in 2010. Phylogenetic analysis of the E-gene classified this isolate as Siberian subtype of TBEV. The Mongolian TBEV strain showed differences in virus titers, plaque sizes, and growth properties in two human neuronal cell-lines. In addition, the 10,242 nucleotide long open-reading frame and the corresponding polyprotein sequence were revealed. The isolate grouped in the genetic subclade of the Siberian subtype. The strain Zausaev (AF527415) and Vasilchenko (AF069066) had 97 and 94 % identity on the nucleotide level. In summary, we herein describe first detailed data regarding TBEV from Mongolia. Further investigations of TBEV in Mongolia and adjacent areas are needed to understand the intricate dispersal of this virus.

Isolation and characterization of tick-borne encephalitis virus from Ixodes persulcatus in Mongolia in 2012

“…1, and 2). The TBEV detection rate in ticks (1.3%) was similar to that in a previous study (1.6%) in Mongolia (Frey et al, 2012). TBEV infected human cases were found mainly in northern Mongolia, especially Selenge aimag (Walder et al, 2006).…”

“…Severe TBE cases have been reported since the 1980s in Selenge aimag and Bulgan aimag (near the border with Russia) (Frey et al, 2012). In Bulgan aimag, the viral genome was detected in a patient in 2008 and from ticks in 2010 and these viral genes were clustered within the Far-Eastern subtype and the Siberian subtype, respectively (Frey et al, 2012;Khasnatinov et al, 2010). However, minimal data are available concerning the biological characteristics of Mongolian TBEV strains (e.g., virulence and viral multiplication).…”

Some aspects on tick species in Mongolia and their potential role in the transmission of equine piroplasms, Anaplasma phagocytophilum and Borrelia burgdorferi L.

“…Piroplasms were detected in ticks (Battsetseg et al 2001(Battsetseg et al , 2002Boldbaatar et al 2005;Tuvshintulga et al 2015Tuvshintulga et al , 2016Karnath et al 2016), livestock (Avarzed et al 1997;Ruegg et al 2007;Altangerel et al 2011Altangerel et al , 2012Sivakumar et al 2012;Munkhjargal et al 2013;Yoshinari et al 2013) and humans (Hong et al 2014) in Mongolia. TBEV was isolated from ticks (Frey et al 2012) and detected in humans in Mongolia (Walder et al 2006;Khasnatinov et al 2010;Muto et al 2015). However, most of these studies were limited in sample size, the pathogens detected or geographical coverage and most of them did not consider multiple infections in ticks.…”

Molecular Biological Detection of Emerging Tick-Borne Zoonotic Pathogens in Ixodid Tick Species

“…Primary vectors for Rickettsiosis, Ehrlichiosis, Lyme disease and Q fever are arthropod ticks. Q fever, Lyme disease, zoonotic Ehrlichiosis and Rickettsiosis are the most detected zoonotic pathogens transmitted through tick engorgement in Mongolia, which makes the area as an endemic by these diseases [2,3,4,5,6]. Preventing tick infestation completely in free ranging livestock farming circumstances is barely impossible in today's condition in many countries around the world.…”