Viruses are the most abundant biological entities on Earth and can be found in a variety of environments. A high prevalence of viruses in marine and freshwater systems was initially reported by Spencer in 1955, but the ecological significance of viruses is insufficiently known even until the present day. Viruses are known to play a key role in the biology of freshwater bacteria: controlling the bacterial abundance, composition of species, and acting as intermediaries in the transfer of genes between bacterial populations. In our study a variety of viromes of the IleBalkhash water basin were identified. It was found that the composition of viruses of the Ile-Balkhash region is made up not only of a wide variety of autochthonous viruses typical for phytoplankton hydro ecosystems, but also of representatives of allochthonous viruses-such families as Coronaviridae, Reoviridae and Herpesviridae-indicating anthropogenic pollution of the basin. The research designed to investigate the viral abundance, spread, infectious cycle, seasonal dynamics, composition of the viral community, and the influence of viruses on the bacteria, phytoplankton and recycling of nutrients, as well as the impact of environmental factors on the viral ecology in a variety of marine and freshwater systems is very relevant nowadays.
Newcastle disease virus (NDV) infects domesticated and wild birds throughout the world, and infections with virulent NDV strains continue to cause disease outbreaks in poultry and wild birds. To assess the evolutionary characteristics of 28 NDV strains isolated from chickens in Kazakhstan and Kyrgyzstan during 1998, 2000, 2001, 2003, 2004, and 2005, we investigated the phylogenetic relationships among these viruses and viruses described previously. For genotyping, fusion (F) gene phylogenetic analysis (nucleotide number 47-421) was performed using sequences of Kazakhstanian and Kyrgyzstanian isolates as compared to sequences of selected NDV strains from GenBank. Phylogenetic analysis demonstrated that the 14 newly characterized strains from years 1998 to 2001 belong to the NDV genotype VIIb, whereas the 14 strains isolated during 2003-2005 were of genotype VIId. All strains possessed a virulent fusion protein cleavage site (R-R-Q-R/K-R-F) and had intracerebral pathogenicity indexes in day-old chickens that ranged from 1.05 to 1.87, both properties typical of NDV strains classified in the mesogenic or velogenic pathotype.
BackgroundCommercially available antiviral drugs, when used in the treatment of viral infections, do not always result in success. This is an urgent problem currently that needs to be addressed because several viruses including influenza and paramyxoviruses are acquiring multi-drug resistance. A potential solution for this emerging issue is to create new antiviral drugs from available compounds of natural products. It is known that the majority of drugs have been developed using compounds derived from actinomycetes, which are naturally occurring gram-positive bacteria. The purpose of this study was to investigate the antiviral properties of extremophilic actinomycetes extracts from strains that were isolated from extreme environments in Kazakhstan.MethodsFive strains of extremophilic actinomycetes isolated from the unique ecosystems of Kazakhstan were extracted and tested for antiviral activity against influenza viruses (strains H7N1, H5N3, H1N1 and H3N2) and paramyxoviruses (Sendai Virus and Newcastle Disease Virus). The antiviral activity of these selected extracts was tested by checking their effect on hemagglutination and neuraminidase activities of the studied viruses. Additionally, actinomycetes extracts were compared with commercially available antiviral drugs and some plant preparations that have been shown to exhibit antiviral properties.ResultsThe main findings show that extracts from strains K-192, K-340, K-362, K-522 and K525 showed antiviral activities when tested using influenza viruses, Sendai Virus, and Newcastle Disease Virus. These activities were comparable to those shown by Rimantadine and Tamiflu drugs, and “Virospan” and “Flavovir” plant preparations.ConclusionsWe identified several extracts with antiviral activities against several strains of influenza viruses and paramyxoviruses. Our research findings can be applied towards characterization and development of new antiviral drugs from the active actinomycetes extracts.
Newcastle disease virus (NDV) infects domesticated and wild birds throughout the world and has the possibility to cause outbreaks in chicken flocks in future. To assess the evolutionary characteristics of 10 NDV strains isolated from chickens in Kazakhstan during 1998 we investigated the phylogenetic relationships among these viruses and viruses described previously. For genotyping, fusion (F) gene phylogenetic analysis (nucleotide number 47-421) was performed using sequences of Kazakhstanian isolates as compared to sequences of selected NDV strains from GenBank. Phylogenetic analysis showed that all newly characterized strains belonged to the genetic group designated as VIIb. All strains possessed a virulent fusion cleavage site (RRQRR/F) belonging to velogenic or mesogenic pathotypes with intracerebral pathogenicity indexes (ICPI) varying from 1.05 to 1.87.
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