Influence of infectivity of transmissible gastroenteritis virus of swine by pancreatin and some unknown factors.

The infectivity of virulent strain, not attenuated strain, of transmissible gastroenteritis virus (TGEV) of swine could be enhanced as much as 50-fold by pancreatin incorporated medium. The mechanism(s) of enhancement was uncertained. Multiplication of TGEV, either virulent or attenuated strain, was inhibited by intestinal fluid of both TGEV infected and noninfected piglets. Pelleting virus particles from intestine fluid was likely to remove all inhibitors and resulted in facilitating the isolation of the virus by using swine testicle (ST) cell line. These findings contribute to the practical application in the isolation and identification of TGEV and in the preparation of high titred virus stocks.