Genetic characterization of the M RNA segment of a Balkan Crimean-Congo hemorrhagic fever virus strain

Abstract

Crimean-Congo hemorrhagic fever (CCHF) virus causes one of the most severe diseases in humans, with a mortality rate of up to 30%. It is transmitted to humans by the bite of hard ticks or by contact with blood or tissues from human patients or infected livestock. Balkan Peninsula is an endemic region of the disease, and sporadic cases or even outbreaks are observed every year. The M RNA segment encodes for the glycoprotein precursor of two surface glycoproteins Gn and Gc. Up to now complete M RNA CCHF virus sequences have been published from strains isolated in Nigeria, China, Pakistan, Tajikistan, and Russia. In the present study, the genetic characterization of the complete nucleotide sequence of the M RNA segment of a Balkan CCHF virus strain, Kosovo/9553/2001, isolated in summer of 2001 from a human fatal case in Kosovo is reported. This is the first published complete M nucleotide sequence of a CCHF virus strain isolated in Balkans. It was found that the Balkan strain is similar to the Russian strain, both strains differing from all other completely sequenced CCHF virus strains by approximately 22% at the nucleotide level forming an independent clade in the phylogenetic tree.

Crimean-Congo Hemorrhagic Fever Virus: Genetic Analysis and Tick Survey in Turkey

“…Several CCHFV S segment sequences from different regions of the world indicate that there are considerable genetic differences between CCHFV isolates (9,14,23,31). Yashina et al (32) hypothesized that an explanation of the genetic diversity between CCHFV strains depends not only on different geographical locations, but also on different tick species.…”

“…Although Hyalomma ticks are one of the major vectors of CCHFV, at least 31 tick species harbor the virus (9). The disease is distributed in Asia, the Middle East, Africa, and southeastern Europe (9,23,26).…”

Lack of genetic diversity in Crimean‐Congo hemorrhagic fever viruses in Turkey: Assessment of present and future patterns of disease

“…Due to frequent reassortment event(s) associated with the M RNA segments, phylogenetic analysis based on the M segment RNA sequences differ from those based on the S and L RNA segment analyses [Morikawa et al, 2007]. In addition, it is likely that reassortment events associated with M RNA segments may result in enhanced virulence [Papa et al, 2005;Ozdarendeli et al, 2008;Papa et al, 2011]. Therefore, investigations of the M gene RNA segment variability are of a great importance for the identification of new isolates and a better understanding of the virulence mechanisms associated with respective CCHFV isolates.…”

The Complete Genomic Sequence of Strain ROS/HUVLV-100, A Representative Russian Crimean Congo Hemorrhagic Fever Virus Strain

“…Individual genome segments of the VLV-100 sequence share 94-99% nucleotide identity with previously sequenced Russian or Eastern European CCHFV isolates [9][10][11][12]. Thus, strain VLV-100 is representative of the CCHFV ''Europe-1'' group [6], and could serve as the modern type strain for this group.…”