• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.395-399
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• 2012

In 2011, several herds in Youngju city in Gyeongbuk province underwent an outbreak of bovine viral diarrhea virus (BVDV) causing high morbidity and mortality. Genetic analysis revealed that two subgenotypes of BVDV-1b (n = 21) and BVDV-2a (n = 7) were identified. The BVDV-1b subgenotype was most frequently detected from our field cases and BVDV-2a subgenotype was also identified in this outbreak. These BVDV-1b infections showed severe acute clinical manifestations similar to BVDV-2 infection. This result reports the detection of BVDV-1b associated with an acute and fatal outbreak of BVDV in Korean indigenous calves.

• Journal of Veterinary Clinics
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• v.27 no.3
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• pp.220-224
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• 2010

Bovine viral diarrhea virus (BVDV) is an important worldwide disease in the livestock industry. To characterize BVDV circulating in Gyeongbuk province in the Republic of Korea which has the highest cattle population density, 365 rectal swabs from clinically BVDV Korean indigenous calves were collected. Fifty cases were identified as positive for BVDV. A phylogenetic analysis of 5'- untranslated regions (UTR) revealed that most of our cases belonged to BVDV-2a (n = 48), while only two cases were classified as BVDV-1a (n = 1) and 1b (n = 1), respectively. These results indicated that BVDV-2a is the most prevalent subgroup in Korean indigenous calves of Gyeongbuk province.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.34-42
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• 2008

Bovine blood, cell, tissue, and organ are used as raw materials for manufacturing biologics such as biopharmaceuticals, tissue engineered products, and cell therapy. Manufacturing processes for the biologics using bovine materials have the risk of viral contamination. Therefore viral validation is essential in ensuring the safety of the products. Bovine viral diarrhoea virus (BVDV) is the most common bovine pathogen and has widely been known as a contaminant of biologics. In order to establish the validation system for the BVDV safety of biologics, a real-time RT-PCR method was developed for quantitative detection of BVDV contamination in raw materials, manufacturing processes, and final products. Specific primers for amplification of BVDV RNA was selected, and BVDV RNA was quantified by use of SYBR Green I. The sensitivity of the assay was calculated to be 1 $TCID_{50}/mL$. The rent-time RT-PCR method was validated to be reproducible and very specific to BVDV. The established real-time RT-PCR assay was successfully applied to the validation of Chinese hamster ovary (CHO) cell artificially infected with BVDV. BVDV RNA could be quantified in CHO cell as well as culture supernatant. Also the real-time RT-PCR assay could detect $10TCID_{50}/mL$ of BVDV artificially contaminated in bovine collagen.

• Korean Journal of Veterinary Service
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• v.45 no.3
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• pp.211-219
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• 2022

Bovine viral diarrhea (BVD) is one of the problematic wasting diseases in cattle leading to huge economic losses. This study was conducted to investigate the prevalence of BVD including transient and persistent infection from cattle farms in Gyeongsangnam-do. A total of 2,667 blood samples from 24 farms were collected and the sera were subjected to ELISA to detect BVD virus (BVDV) antigen, E^rns. 5' untranslated region (5'-UTR) of BVDV-positive samples was sequenced to identify the genotype, and compared with isolates previously reported elsewhere. There were fourteen BVDV-positive calves from 2,667 samples (positive rate: 0.52%) from first ELISA testing followed by eight persistently infected out of eleven BVDV-positive samples (72.73%) in secondary ELISA that was conducted in at least four weeks suggesting the circulation of BVDV in the area. Sequencing analysis exhibited that thirteen BVDV-positive samples were identified as BVDV-1b and one sample was BVDV-2a. Phylogenetic analysis revealed that the BVDV-1b-positive samples showed the highest homology in nucleotide sequence to Korean isolates collected from Sancheong, Gyeongsangnam-do, while the BVDV-2a-positive sample (21GN7) was more similar to reference strains collected outside South Korea. This study will provide the recent fundamental data on BVD prevalence in Gyeongsangnam-do to be referred in developing strategies to prevent BVDV in South Korea.

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.635-639
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• 2010

The prevalence of bovine viral diarrhea virus (BVDV) in Korean indigenous calves with diarrhea in Gyeongbuk province was investigated. Seventy-five cases were identified as BVDV positive in the diarrhea stools. Phylogenetic analysis revealed that all our cases were classified as BVDV-2a. Most of the present BVDV-2a cases were isolated from calves showing clinical signs of watery diarrhea. Our observations indicate that not all BVDV-2 infections cause clinically severe disease. This study shows the high incidence of BVDV-2 infection in Gyeongbuk province. Therefore, the results suggest that a vaccine development and immunization strategies are required for the effective control of BVDV infection in the Republic of Korea.

• Korean Journal of Veterinary Service
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• v.36 no.1
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• pp.1-6
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• 2013

Since the 1980's, several kinds of inactivated bovine viral diarrhea virus (BVDV) vaccines have been used to immunize domestic animals such as cattle and goat in Korea. Immunogenicity of the BVDV vaccines has been checked by the Korean Veterinary Authority using laboratory animals. In this study, we applied a molecular method to investigate the genetic characterization of the BVDV genes in six commercial inactivated BVDV vaccines, and determined the efficiency of two extraction reagents (i.e., sodium citrate or isopropyl myristate) to separate the vaccine antigens from the antigen/adjuvant complexes. Six partial non-coding regions (288 bp) were successfully amplified with specific primer sets, which demonstrated that sodium citrate is more efficient in extracting viral RNA from inactivated gel vaccines than isopropyl myristae. In addition, we identified the virus strains from the vaccines by analyzing the nucleotide sequences of the 5' non-coding region (NCR) of BVDV. The nucleotide similarity of the partial 5' NCR ranged from 95.1 to 100% among BVDV vaccine strains, respectively, indicating that a few manufacturers used different BVDV strains to produce their vaccines.

• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.169-171
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• 2007

The aim of this study was to detect bovine viral diarrhea virus (BVDV) from calves in Chonbuk province. Blood samples were taken from ninety-two dairy calves. Capture enzyme-linked immunosorbent assay (ELISA) was used to detect BVDV. BVDV were detected in eight out of ninety-two (8.6%) dairy calves. BVDV were detected in one of twenty five of female calves and one of twenty three of male calves of 4 months old, whereas in the 5 months age group, BVDV were detected in low of twenty three of female calves and two of twenty one of male calves. There were no significant differences (p>0.05) in the detection rate of BVDV on the basis of sex. On the other hand, ages of calves had significant differences (p<0.05) on the prevalence of BVDV.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.578-581
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• 2009

A 25-day-old, Korean indigenous calf was presented with a 10 days history of respiratory disorders and bloody diarrhea, and died. This calf was extremely unthrifty compared to others and had evidence of chronic diarrhea based on matting of feces in the hair of the tail and perineum. Ecchymotic hemorrhages were observed on multiple organs at necropsy. Bovine viral diarrhea virus (BVDV) infection was identified by RT-PCR. The phylogenetic analysis showed that this case belonged to BVDV-2a subgroup and was related to highly pathogenic USA isolate 890 (U18059). This case provided evidence for circulation of BVDV-2 in Republic of Korea. The occurrence of BVDV-2 was also reconfirmed.

• Journal of Veterinary Clinics
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• v.28 no.3
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• pp.287-290
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• 2011

Phylogenetic and nucleotide analysis revealed that severe acute bovine viral diarrhea virus (BVDV) outbreaks from Korean indigenous calves belonged to BVDV-2a, and were identical to those of the highly pathogenic BVDV-2 strain 890, with identical virulence markers and classified as highly virulent. These outbreaks affected young calves (20 and 40 day-old) and were characterized by hemorrhagic diarrhea, depression, anorexia, and weakness. The identification of the highly virulent BVDV-2 isolates among Korean indigenous calves may have important implications for epidemiological studies, diagnostic and immunization strategies.

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