P-20. Propagation of avian rotavirus in embryonated hen's egg
Abstract
Group A avian rotaviruses replicate efficiently in vitro in cell cultures. However, there is lack of published data on their adaptability to embryonated eggs. The present study was proposed to adapt the chicken rotavirus strain CH2 for its propagation in ovo. MA104 cell culture grown CH2 strain of rotavirus was inoculated by allantoic and amniotic routes in the embryonated eggs procured from poultry farm. The eggs were harvested after 24/48/72 hours. Serial passaging of the harvested material was carried out upto 6th passage level. The allantoic and amniotic fluid harvests were tested by antigen capture ELISA, immune electron microscopy (IEM), RNA-polyacrylamide gel electrophoresis (PAGE) and VP6 gene based reverse transcriptase polymerase chain reaction (RT-PCR) to examine the viral antigen, full virus particles, RNA migration pattern and VP6 nucleotide sequence, respectively. With increase in the passage level of CH2 strain in eggs, mortality of eggs increased. However, percent positivity to viral antigen in ELISA showed increase in cyclic manner. Full virus particles were visualized by electron microscopy while presence of viral RNA and its 11 segments were shown by RT-PCR and PAGE respectively. The propagation of virus was monitored upto passage 6, however, with low titres. The virus was infectious to normal MA104 cell culture. llantoic and amniotic membranes of embryonated eggs support replication of chicken rotavirus strain CH2. The study adds to the base line data on adaptation and propagation of avian rotaviruses in embryonated egg system.
