Isolation and characterization of the first Chinese strain of porcine Teschovirus-8

Investigations were carried out to identify the causal agent of acute diarrhea, respiratory distress, and death of pigs on a swine farm in Jilin Province, northern China. Only porcine Teschovirus (PTV, designated as PTV-8 Jilin/2003) was isolated from samples of organs. The presence of PTV was confirmed by the production of a specific cytopathic effect on susceptible cells and by the results of the immunoperoxidase monolayer assay (IPMA), polymerase chain reaction, and electron microscopy. Other pathogenic agents causing diarrhea, respiratory distress, and death (including porcine rotavirus, transmissible gastroenteritis virus of swine, porcine epidemic diarrhea virus, classical swine fever virus, pseudorabies virus, porcine circovirus, porcine reproductive and respiratory syndrome virus, Japanese encephalitis virus, Mycoplasma, Leptospira, Streptococcus, Listeria, and Brucella species) were excluded as possible causal agents because they were not associated consistently with the disease of the pigs. PTV-8 Jilin/2003 was adapted to grow in swine primary kidney (PK-15) cells and in a swine testicular cell line (ST cells). When inoculated into healthy pigs, PTV-8 Jilin/2003 caused the same symptoms as those observed in the affected herd. It is concluded that PTV-8 Jilin/2003 was the causal agent of this disease.