Determination of reproductive properties of virulent and vaccine classical swine fever virus strains in primary and continuous cell cultures

Classical swine  fever  (CSF) is a highly dangerous porcine disease. CSF outbreaks are annually notified in several countries. Despite the availability of specific prevention tools, the disease spread risk still persists both at country level and at world level. Hence, the disease surveillance and eradication require highly sensitive methods for early diagnosis of the infection and for tests for the virus circulation in the environment.  Development of up-to-date  diagnostic methods is based on well-established  virus cultivation system; therefore, CSF virus reproduction enhancement,  tests of new cell lines without  endogenous  contamination  for their possible use are still of current importance. The said study was aimed at testing of primary and continuous cell cultures for their susceptibility to classical swine fever virus (vaccine virus strains and some field virus isolates recovered in the Russian Federation) and detection of the virus reproduction dynamics with real-time polymerase chain reaction with fluorescent hybridization probes used for detection. Virus replication intensity in primary and continuous cell cultures was also analyzed. The CSF virus was found incapable of replicating in some cell cultures without  its preliminary adaptation.  Primary porcine and lamb testicle cell cultures grown in minimal essential medium supplemented  with 10% normal CSFV-negative porcine serum instead  of fetal bovine serum were shown to be useful for the virus accumulation, both for vaccine strains and field isolates. Cultivation parameters and optimal minimal essential medium composition contributing to the 4–10-fold  increase in the virus accumulation  both in primary and continuous  cell cultures were determined

Molecular characterization of African swine fever virus isolates originating from outbreaks in the Russian Federation between 2007 and 2011

African swine fever is one of the most important viral diseases of pigs and which caused significant economic damage on the pig production worldwide. Nowadays, it is still present on the African continent, in Transcaucasus countries (TCC), on Island of Sardinia and in Russia. Outbreaks of the disease have been reported in Russia for the last four years, affected especially the Southern Federal District of the country. Since 2010, a new outbreak area has been observed in the Northwestern Federal District.In order to study the evolution of African swine fever virus (ASFV) isolates, strains were collected in the Russian Federation from 2007 to 2011 and investigated by means of partial sequencing and fragment length polymorphism. In detail, 7 variable regions, namely B646L, E183L, I196L, B602L, I73R/I329R, I78R/I215L and KP86R were investigated. Phylogenetic analyses revealed 100% nucleotide identity of B646L and E183L gene sequences of all examined isolates. All isolates formed one genetic cluster within genotype II. Moreover, no amplified fragment length polymorphism (AFLP) was observed for B602L, I196L, I73R/I329R, and I78R/I215L genes. The flanking primers used to amplify the KP86R gene failed to amplify a product in all the isolates. The obtained data strongly suggests that only one ASFV virus variant caused the outbreaks from 2007 to 2011 in the territory of the Russian Federation. © 2012 Elsevier B.V

GENOMIC ABERRATIONS IN DNA OF AFRICAN SWINE FEVER VIRUS CIRCULATING IN THE TERRITORY OF THE RUSSIAN FEDERATION

The paper is devoted to analysis of genome variability of African swine fever (ASF) virus isolates recovered in the Russian Federation territory. Complete nucleotide sequences of the following ASF virus isolate genomes were obtained by pyrosequencing: Kashino 04/13, Odintsovo 02/14 and Karamzino 02/13. Multiple single insertions and deletions as well as distinctly localized two tandem repeats were found by comparative analysis of genomes of the said isolates and Georgia 2007/1 isolate. Notably that 17-nucleotide tandem repeat was detected in 9R/10R intergenic region of MGF505 multigene family in genomes of Shikhobalovo 10/13 and Karamzino 02/13 isolates for the first time

ANALYSIS OF MONITORING STUDIES ON AFRICAN SWINE FEVER VIRUS DNA DETECTION CARRIED OUT IN 2017

The paper describes the results of testing of biomaterial from domestic pigs and wild boars by real-time PCR used for African swine fever virus genome detection, carried out in the FGBI “Federal Centre for Animal Health” (Vladimir). In 2017 8,500 samples from 44 subjects of the Russian Federation were tested within the framework of the state laboratory monitoring. African swine fever virus genome was detected in 504 samples. In 2017 ASF outbreaks were registered in the Urals and Siberian Federal Districts of the RF for the first time. The conducted research and persistent ASF infection in the territory of the RF have demonstrated the need for further surveillance in the populations of susceptible animals. Development, organization and implementation of the program for ASF spread surveillance in wild fauna remains a high priority. It is necessary to create and implement sampling schedules with uniform sampling of biomaterial and submission of the collected samples to the research laboratories for timely ASF outbreak containment at the regional level