Molecular diversity and evolutionary history of rabies virus strains circulating in the Balkans

Abstract

Molecular studies of European classical rabies viruses (RABV) have revealed a number of geographically clustered lineages. To study the diversity of Balkan RABV, partial nucleoprotein (N) gene sequences were analysed from a unique panel of isolates (n5210), collected from various hosts between 1972 and 2006. All of the Balkan isolates grouped within the European/Middle East Lineage, with the majority most closely related to East European strains. A number of RABV from Bosnia & Herzegovina and Montenegro, collected between 1986 and 2006, grouped with the West European strains, believed to be responsible for the rabies epizootic that spread throughout Europe in the latter half of the 20th Century. In contrast, no Serbian RABV belonged to this sublineage. However, a distinct group of Serbian fox RABV provided further evidence for the southwards wildlife-mediated movement of rabies from Hungary, Romania and Serbia into Bulgaria. To determine the optimal region for evolutionary analysis, partial, full and concatenated N-gene and glycoprotein (G) gene sequences were compared. Whilst both the divergence times and evolutionary rates were similar irrespective of genomic region, the 95 % highest probability density (HPD) limits were significantly reduced for full N-gene and concatenated NG-gene sequences compared with partial gene sequences. Bayesian coalescent analysis estimated the date of the most common recent ancestor of the Balkan RABV to be 1885 (95 % HPD, 1852(95 % HPD, -1913, and skyline plots suggested an expansion of the local viral population in 1980-1990, which coincides with the observed emergence of fox rabies in the region.

Diversity and Epidemiology of Mokola Virus

“…The estimation of viral lineage divergence times and subsequent application of a molecular clock is dependent on an accurate estimation of the rate of nucleotide substitution. Bayesian techniques using the Markov Chain Monte Carlo (MCMC) methods have been successfully applied to estimate the evolutionary rate and divergence times from dated sequences of RABVs [36], [37], [38], [39], [40]. This study applied a relaxed molecular clock to N-, M-, P- and G-gene datasets to obtain estimates of the time to the most recent common ancestor (MRCA) and rate of evolution for MOKV.…”

Clinical rabies in cattle imported into Croatia

“…NEE strains have never been established in the west Balkans (McElhinney and others 2011), including Croatia (Lojkić and others 2012). One reason for the low genetic diversity of currently circulating RABV strains in the west Balkans and Croatia could be natural barriers like rivers or high mountain ranges which may play a significant role in limiting the spread of distinct rabies groups (Bourhy and others 1999, Johnson and others 2007, McElhinney and others 2011).…”

“…One reason for the low genetic diversity of currently circulating RABV strains in the west Balkans and Croatia could be natural barriers like rivers or high mountain ranges which may play a significant role in limiting the spread of distinct rabies groups (Bourhy and others 1999, Johnson and others 2007, McElhinney and others 2011). However, it is known that Romanian sequences showed a high degree of heterogeneity with six different lineages identified and that the RABV group most similar to the NEE group was isolated in Romania's northern regions where the country borders with Ukraine (Turcitu and others 2010).…”

Partial sequencing analysis of the NS5B region confirmed the predominance of hepatitis C virus genotype 1 infection in Jeddah, Saudi Arabia

“…The resultant HCV RNA samples were stored at −70°C until use [33]. The presence of the HCV-NS5B gene was determined by nested PCR using the One-step RT-PCR Master Mix kit and the Hot start Taq plus PCR Master Mix Kit (QIAGEN) using the primers shown in Table 1.…”