• Korean Journal of Veterinary Service
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• v.32 no.1
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• pp.11-18
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• 2009

Porcine epidemic diarrhea virus (PEDV), an enveloped single stranded RNA virus in the family Coronaviridae, causes acute viral enteric disease in piglets. Recently outbreaks of porcine epidemic diarrhea (PED) have been rare in Europe but frequent in Asia. In Korea, the increase of PED prevalence is showing specially in postweaning pigs. The purpose of this study was to investigate nucleotide sequence of nucleocapsid protein gene of PEDV field isolates from postweaning pigs in Korea and get more information about the viruses. A total of 15 postweaing pigs clinically suspected of PEDV infection by severe watery diarrhea and dehydration were used in this study. Viral RNA was extracted from small intestines and stools of the pigs. The N gene was amplified by nested RT-PCR, purificated, sequenced, analyzed and then compared with published sequences of other PEDV strains. Three PEDVs were isolated from the suspected postweaning pigs. The N gene of three PEDV field isolates consisted of 483 nucleotides. These PEDV field isolates showed nucleotide sequence homology range from 99.6% to 95% with Chinese strains, from 99.8% to 95.2% with Korean strains, from 97.3% to 95.7% with Japanese strains and from 96.5% to 95.7% with Belgium and British strains. The encoded pritein shared range from 98.8% to 95.6% with Chinese strains, from 99.4% to 95% with Korean strains, from 97.5% to 96.3% with Japanese strains, from 95.6% to 95% with Belgium and British strains. By phylogenetic tree analysis based on nucleotide sequence, three PEDV field isolates were clustered into two groups which were Chinese isolate groups and other Korean isolate groups. These results indicated that some of PEDV field isolates prevailing in Korean postweaning pigs may be associated with those of Chinese strains and other Korean strains.

• Korean Journal of Veterinary Research
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• v.31 no.3
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• pp.295-302
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• 1991

From 1988 to 1989, 8 strains of canine parvovirus-2(CPV-2) were isolated from the fecal specimens from the dogs that were clinically diagnosed as canine parvoviral enteritis in the veterinary hospitals located in the regions of Taejeon and Chungbuk province. The biological and physicochemical properties for the isolates were studied. Among 62 fecal samples collected from the dogs with enteric diseases, 24(38.7%) showed the haemagglutinating activity to porcine erythrocyte ranging from 16 to 16,384 of HA titers. In cytopathological studies with CRFK cells, intranuclear inclusion bodies were observed in all of eight specimens with the high HA titer over 1,000, of which three specimens showed cytoplasmic inclusions concurrently with the intranuclear inclusion bodies. It was found that the isolates revealed the highest haemagglutinating activity with porcine erythrocytes and the relatively lower haemagglutination titers with the erythrocytes from cat and rabbit. None of erythrocytes from the other animals reacted with the isolates. By the cross-haemagglutination inhibition test for the isolates with the reference viruses and sera, the isolates were evidently identified as the strains of CPV-2. In physicochemical property test, the isolates were stable in lipid solvent, pH and heat treatment at $56^{\circ}C$ for 30 min, and showed the virus particle size less than 25 nm, containing a DNA genome.