Determination of virulence of KTY-PED01 virus strain isolated in the North, Viet Nam

Abstract

In this study, we investigated the virulence of KTY-PED01 virus strain in the piglet at 5-days old. The experimental pigs (negative with PEDV antibody) were infected with PED virus strain. Each experimental pig was orally inoculated with a dose: 2 ml of 2x103TCID50/ml (2ml/pig). After inoculation, the experimental pigs were recorded for the clinical signs, gross and histological lesions of some tissues in 15 days post inoculation. The studied results demonstrated that the infected pigs with PED virus strain presented the clinical signs and symptoms of fever, vomiting, dehydration, rough hair, thin flanks and diarrhea. The result of testing fecal samples through RT-PCR technique indicated that the KTY-PED01 virus strain was presented in the feces of the infected pigs at 1 day post inoculation. The gross lesions were consistently observed, including intestine inflammation, hemorrhage, thin wall and bloating stomach, containing undigested food, and kidneys with spotting hemorrhage, lung inflammation. The lymph nodes were characterized by swelling and hemorrhage of the pigs infected with KTY-PED01 virus strain. The histological lesions included villous atrophy and lymphocytic inflammation in the intestine, hemorrhage, inflammatory cell infitration, haemorrhagic lymph nodes. The results of our study showed that the KTY-PED01 virus strain is capable in causing severe disease in pigs with clinical signs, symptoms, gross lesions and histological lesions were similar to those of highly pathogenic PED virus strain identified previously in the North, Viet Nam.