ABSTRACT
INTRODUCTION: The rapid spread of African swine fever in the Kaliningrad region makes it necessary to use the methods of molecular epidemiology to determine the dynamics and direction of ASF spread in this region of Russia. The aim of the study was to determine single nucleotide polymorphisms within molecular markers K145R, O174L and MGF 505-5R of ASFVs isolated in Kaliningrad region and to study the circulating of the pathogen in European countries by subgenotyping and spatio-temporal clustering analysis. MATERIALS AND METHODS: Blood samples from living domestic pigs and organs from dead domestic pigs and wild boars, collected in the Kaliningrad region between 2017 and 2022 were used. Virus isolation was carried out in porcine bone-marrow primary cell culture. Amplicons of genome markers were amplified by PCR with electrophoretic detection and subsequent extraction of fragments from agarose gel. Sequencing was performed using the Sanger method. RESULTS: The circulation of two genetic clusters of ASFV isolates on the territory of the Kaliningrad has been established: epidemic (K145R-III, MGF 505-5R-II, O174L-I - 94.3% of the studied isolates) and sporadic (K145R-II, MGF 505-5R-II, O174L-I - 5.7%). CONCLUSION: The broaden molecular genetic surveillance of ASFV isolates based on sequencing of genome markers is necessary in the countries of the Eurasian continent to perform a more detailed analysis of ASF spread between countries and within regions.
Subject(s)
African Swine Fever Virus , African Swine Fever , Genome, Viral , Animals , African Swine Fever Virus/genetics , African Swine Fever Virus/isolation & purification , African Swine Fever Virus/classification , Swine , African Swine Fever/virology , African Swine Fever/epidemiology , Russia/epidemiology , Phylogeny , Polymorphism, Single Nucleotide , Genetic Markers , Sus scrofa/virology , Spatio-Temporal AnalysisABSTRACT
INTRODUCTION: Up-to-date data and full characterization of circulating ASFV isolates play a crucial role in virus eradication and control in endemic regions and countries. The aim of the study was to evaluate and characterize the molecular and biological properties of the ASFV isolate ASF/Tatarstan 20/WB-12276, conduct phylogenetic analysis, and compare the results with isolates circulating in Europe and Asia. MATERIALS AND METHODS: For bioassay, eight heads of the Large White pigs weighing 15-20 kg/head were used. Detection of specific anti-ASFV antibodies by ELISA and immunoperoxidase method. Detection of ASFV genome was performed by qPCR. Isolation of ASF/Tatarstan 20/WB-12276 and determination of titer were performed in pig spleen cell culture. Sequencing was carried out by the Sanger method. RESULTS: The virus was characterized as highly virulent and capable of causing acute to subacute forms of ASF. Phylogenetic analysis revealed substitutions in the genome of the ASF/Tatarstan 20/WB-12276 isolate (IGR/I73R-I329L and I267L markers) that supported the clustering of the studied variant with isolates prevalent in most of Europe and Asia. CONCLUSION: For the first time, the molecular and biological properties of the ASF/Tatarstan 20/WB-12276 virus isolate taken from a wild boar shot on the territory of the Republic of Tatarstan were studied and analyzed.
