Isolation and identification of viruses from piglet enteritis

Abstract

Out of 156 samples from piglet enteritis 21 samples (13.4%) were positive for viruses, 16 isolates (10.26%) belonged to rotaviruses and the remaining 5 were enteroviruses (3.21%). The viruses Were successfully cultivated in pig kidney cell-cultures. Pancreatin was needed for the growth of rotaviruses. Increase in titres from third to fifth passage level indicated the adaptation of viruses. Rotaviruses produced granulation as the main characteristic CPE, whereas rounding of cells and shrinkage of infected monolayers were recorded in enteroviruses. Rotaviruses were more thermostable than
emeroviruses as they retained some residual infectivity on exposure to 60^oC for 30 min. They Were, however, completely inactivated at 60^oC within 1 hr. Effect of pH was almost similar for both the viruses. They could withstand pH3, 5 and pH 8 though log 3 fall and log 1 fall were observed at pH 8 for enteroviruses and rotaviruses respectively. Ether and chloroform had no effect on enteroviruses. Chloroform had little effect on rotaviruses. Both the viruses were RKA type as their replication was not inhibited by IUdR or FUdR. Rotaviruses agglutinated only pig red blood cells. Rotaviral isolates were finally confimed by immunodiffusion test. They produced single precipitin lines with OSU group A rotaviral antiserum and hence designated as group A rotaviruses.