Selection of highly immunogenic porcine rotavirus strains isolated from tissues of affected animals

The aim of the study was to select highly immunogenic porcine rotavirus strains. Virus-containing samples were collected from dead piglets up to 10 days old from farms affected by rotavirus disease in the Republics of Bashkortostan and Tatarstan. PK-15 and SPEV cell culture lines were used to isolate the pathogen. Blind passages of suspensions of pathological material and aforementioned cell cultures were performed. Seven passages were performed during the study period. To study the biological properties of the isolated cells, studies were conducted to evaluate one of the virus’s most important biological properties: its cytopathic effect on the animal cells it infects. Cell cultures (PK-15 and SPEV) were used as a biological model. It was found that 6 of 32 samples collected from lung, spleen and intestinal tissue exhibited a cytopathic effect, which was more pronounced after 48-96 hours in passage 3, manifested by cell rounding and destruction, vacuolization, and cytoplasmic granulation. After passage 7, PK-15 and SPEV cells lost their ability to adhere to glass and remained suspended in the maintenance medium. The cytopathic effect was more pronounced when the virus was isolated from intestinal tissue. The viral suspension was frozen at -60°C. The presence of rotavirus ribonucleic acid was confirmed by real-time reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay.