• Korean Journal of Veterinary Service
• /
• v.36 no.2
• /
• pp.105-110
• /
• 2013

Bovine viral diarrhea virus (BVDV) is very important disease in domestic and wild ruminants and has a world wide distribution. Cattle persistently infected with BVDV (BVDV-PI) are the primary reservoir for BVDV infection in Korean native cattle herds. The prevalence of cattle persistently infected with BVDV (BVD-PI) was determined using 4,260 heads from 29 Korean native cattle farms at 8 districts from 2011 to 2012. The sera and ear nothches were collected for each sample. We surveyed BVD-PI cattle using antibody ELISA and antigen capture ELISA for detection of antibody and antigen respectively. Three thousand seventy-six cattle (72.2%) were positive for BVDV antibody and a total of 27 BVD-PI cattle were found in 12 farms. 11 cattle (40.7%) out of the total 27 BVDV-PI cattle were six months old or under. The positive rate of BVDV antibody (83.2%) from 12 farms with BVD-PI cattle was higher than the positive rate of BVDV antibody (63.6%) from 17 farms without BVD-PI cattle.

• The Plant Pathology Journal
• /
• v.35 no.5
• /
• pp.508-520
• /
• 2019

Interplay between Cymbidium mosaic virus (CymMV)/Odontoglossum ringspot virus (ORSV) and its host plant Phalaenopsis equestris remain largely unknown, which led to deficiency of effective measures to control disease of P. equestris caused by infecting viruses. In this study, for the first time, we characterized viral small interfering RNAs (vsiRNAs) profiles in P. equestris co-infected with CymMV and ORSV through small RNA sequencing technology. CymMV and ORSV small interfering RNAs (siRNAs) demonstrated several general and specific/new characteristics. vsiRNAs, with A/U bias at the first nucleotide, were predominantly 21-nt long and they were derived predominantly (90%) from viral positive-strand RNA. 21-nt siRNA duplexes with 0-nt overhangs were the most abundant 21-nt duplexes, followed by 2-nt overhangs and then 1-nt overhangs 21-nt duplexes in infected P. equestris. Continuous but heterogeneous distribution and secondary structures prediction implied that vsiRNAs originate predominantly by direct Dicer-like enzymes cleavage of imperfect duplexes in the most folded regions of the positive strand of both viruses RNA molecular. Furthermore, we totally predicted 54 target genes by vsiRNAs with psRNATarget server, including disease/stress response-related genes, RNA interference core components, cytoskeleton-related genes, photosynthesis or energy supply related genes. Gene Ontology classification showed that a majority of the predicted targets were related to cellular components and cellular processes and performed a certain function. All target genes were down-regulated with different degree by vsiRNAs as shown by real-time reverse transcription polymerase chain reaction. Taken together, CymMV and ORSV siRNAs played important roles in interplay with P. equestris by down modulating the expression levels of endogenous genes in host plant.

• Korean Journal of Microbiology
• /
• v.30 no.3
• /
• pp.177-180
• /
• 1992

Among 120 U. maydis strains isolated in Korea 14 different strains containing specific viral dsRNA segments were analyzed for the distribution of dsRNA and the production of toxin protein. Several distinctive dsRNA patterns were identified, 9 cases of P type with typical H, M and L ds RNA and one case of non-P-type, the frequency of a specific isolate was decreased with increasing number of dsRNA segments. The presence of dsRNA had no effect on the cultural or morphological phenotype of the host. Two isolates containing P type dsRNA segments appeared to produce toxin protein (killer strains) which inhibited the growth of 4 isolates (sensitive strain) with different susceptibility. Two killer strains contain unique M dsRNA segment which may code for toxin protein. However, the presence of toxin-sensitive strains among dsRNA-free isolates was similar to that of ds RNA containing strains.

• Korean Journal of Veterinary Service
• /
• v.20 no.4
• /
• pp.323-329
• /
• 1997

An outbreak of duck septicemia caused by Pasteurella anatipestifer was studied in Chonnam province. The outbreaks of duck septicemia has become an economically important disease in duck farm. The present study undertaken to identify the etiological agent of duck septicemia and to evaluate the efficacy of bacterin against P anatipestifer in Chonnam province during period from May to December 1996. The results obtained were as follows ; 1. The distribution of etiological agents from collected 328 duck samples were Pasteurella anatipestifer(57%), Escherichia coli(21%), duck viral hepatitis virus(4%), Salmonella sp(1%) and others (10%). 2. The agglutination titers of autogenous vaccine were increased after End vaccination and reached highest at 5-6 weeks post inoculation at the titers of 6.0-4.0.

• Korean Journal of Veterinary Research
• /
• v.46 no.1
• /
• pp.21-25
• /
• 2006

Iridovirus is an icosahedral cytoplasmic double-stranded DNA virus with a genome size of 170-200kb. Outbreaks of fish iridovirus infection are characterized by their wide geographic distribution and broad host spectrum, especially in water temperatures of $25-27^{\circ}C$ Recently, the causative agent of high mortalities in flounder (Paralichthys olivaceus) was identified as fish iridovirus in Korea. Iridoviral infection repeatedly occurs in the same area for long periods, suggesting the possibility of viral infection in nursery. To examine this, the existence of iridovirus in juvenile flounders was detected by PCR using virus-specific primers. Antibodies induced against this virus were also examined using ELISA. As a result, juvenile fish in nursery were found to be previously infected with iridovirus, suggesting that proper prevention systems are required.

• Journal of Microbiology and Biotechnology
• /
• v.10 no.5
• /
• pp.714-720
• /
• 2000

Antigens of Herpes simplex virus type 1 (HSV-1) strain F were immunoblotted to identify the most immunodominant one, and the localization of this antigen was then studied using immunoelectron microscopy. The 67.8 kDa antigen appeared to be the most immunodominant one in a mouse model, and it showed randomly scattered and partially clustered distribution on the surface of the virion. The localization study was performed using immunogold with polyclonal anti-HSV-1 sera produced from BALB/c mice, and immunofluorescence demonstrated that the viral products in the HSV-2 infected Vero cells were distributed throughout the infected host cell, however, mainly on the surface of the host membrane.

• Clinical and Experimental Pediatrics
• /
• v.64 no.6
• /
• pp.260-268
• /
• 2021

Since the 2000s, the major causes of acute gastroenteritis in children in Korea have been identified by classifying the pathogens into viruses, bacteria, and protozoa. For viruses, the detection rate is 20%-30%, and norovirus is being increasingly detected to account for the majority of viral gastroenteritis cases. In addition, despite the dissemination of the rotavirus vaccine, many rotavirus infections persist, and its seasonal distribution is changing. The detection rate of bacterial pathogens is 3%-20%, with Escherichia coli and Salmonella spp. infections being the most common, while the incidences of Bacillus cereus and Campylobacter spp. infections are gradually increasing. Owing to intermittent outbreaks of gastroenteritis caused by individual bacteria as well as the inflow of causative bacteria, such as E. coli, Vibrio spp., and Campylobacter spp., from overseas, continuous surveillance of and research into the characteristics and serotypes of each bacterium are needed.

• Journal of Veterinary Science
• /
• v.24 no.2
• /
• pp.18.1-18.7
• /
• 2023

Tibet orbivirus (TIBOV) was identified as a novel orbivirus in 2014. Antibodies against TIBOV were detected in cattle, Asian buffalo, and goats, while all the sequenced TIBOV strains were isolated from mosquitos and Culicoides. The known TIBOV strains have been classified into four putative serotypes. In this study, two TIBOV strains isolated from Culicoides spp. in Shizong County of Yunnan Province, China, were fully sequenced. The phylogenetic analysis of outer capsid protein 2 (VP2) indicated that these two viral strains belong to two novel putative serotypes of TIBOV. The updated putative serotypes may help in an investigation of the distribution and virulence of TIBOV.

• Journal of fish pathology
• /
• v.20 no.3
• /
• pp.211-220
• /
• 2007

Red sea bream iridovirus disease (RSIVD) cause massive economic losses in marine aquaculture industry in Korea. The causative agent of this disease (RSIV) infects a wide range of fish species. The aims of this study were to monitor RSIV in wild marine fishes and to give critical information for controling the disease through prophylactic methods. Prevalence of the viral disease, geological distribution and reservoir of the virus were investigated using wild marine fishes captured in southern coast and east china sea for two years. (Polymerase Chain Reaction) PCR results showed that RSIV were detected in 39 (24.3%) out of 160 fish. MCP gene sequences of viral strains isolated in this study were closely related to that of a reference strain, red seabream-K, belonging to Megalocytivirus subgroup Ⅲ. The results suggest that some of wild marine fishes are RSIV carriers and may spread the pathogen directly to fish farmed in coastal area.

• Korean Journal of Veterinary Research
• /
• v.33 no.2
• /
• pp.269-275
• /
• 1993

Tissue distribution of RHDV in rabbits were examined by immunofluorescence and ABC methods. Tissues including liver, spleen, kidneys, lungs and brain were frozen, cut in a crycut, and fixed in 10% buffered formalin, embedded in paraplast, and cut $5{\sim}7{\mu}m$ thickness. Sections were immunostained Tissue distribution of RHDV in rabbits were examined by immunofluorescence and ABC methods. Tissues including liver, spleen, kidneys, lungs and brain were frozen, cut in a crycut, and fixed in 10% buffered formalin, embedded in paraplast, and cut $5{\sim}7{\mu}m$ thickness. Sections were immunostained with primary antiserum and conjugated second antibodies as recommended by manufacturer. None of the cultures tested showed virus-induced phenomena. Immunoreactive products were commonly found in the liver, in some cases there were also positive staining in the spleen and kidneys. Other organs showed weak or insignificant immunoreactions. By ABC method on the formalin-fixed, paraffin-embedded liver tissues, strong immunoreactivity was found in the periportal triad lesions and peripheral lesions of the hepatic lobules. Immunoreactive products showed diffuse fine granular in the cytoplasm of hepatocytes and sinusoidal cells. In some cells, immunoproducts marginate at the periphery of the cells. The intensive staining of the cytoplasm of infected cells allowed their exact differentiation from surrounding uninfected cells. The positive area involved coincided with histopathological lesion on serial liver sections. In conclusion, liver was proved to be a consistent target organ in RHD, and the immunoperoxidase method in the section of formalin-fixed, paraffin-embedded hepatic tissue could be broadly used for the routine diagnosis of the disease.