• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.237-243
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• 2019

Avian reovirus (ARV) is the pathogenic agent of tenosynovitis and malabsorption syndrome in broiler, which has caused significant economical losses due to poor feeder efficiency and stunting. In order to determine the prevalence of ARV infection in poultry farms in Jeonbuk province, Korea, we performed a surveillance study by testing 179 cecal samples from 131 broiler farms for virus detection, and 1,181 serum samples from 33 broiler farms (n=292) and 22 broiler breeder farms (n=1,525) for antibody detection in the province. Virological examination using RT-PCR showed that ARV were detected in 26.0% of the tested farms (34/131),with the highest positive rates in broilers of 6 days old or more in summer season. In serological test using ELISA, broiler and broiler breeder farms examined were all ARV antibody positive. In broiler, the positive rate and antibody titers showed a tendency to decrease with age in contrast to those of broiler breeders. Our results indicate that ARV is ubiquitous in broilers and broiler breeders in the province.

• Korean Journal of Veterinary Service
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• v.35 no.2
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• pp.129-131
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• 2012

Blood samples were collected from 672 goats in 60 farms from five provinces of Korea between November 2009 and August 2011. The prevalence of antibodies to pestiviruses was investigated. The examination for antibodies was performed using an enzyme-linked immunosorbent assay (ELISA) detecting antibodies to the bovine viral diarrhea virus (BVDV) and border disease virus (BDV). All blood samples were screened using reverse transcription-polymerase chain reaction (RT-PCR) with primer pairs specific to common pestivirus genome regions. The observed individual seroprevalence was 1.49% and herd seroprevalence was 11.67%. Also, the specific genomes to pestiviruses were detected in 3 out of the 915 clinical samples (0.45%). Based on the nucleotide sequence data, detected pestiviruses were belonged to two BVDV type-1 and one BVDV type-2. The pestivirus infection has been occurred among Korean black goats. However, our results indicate that the prevalence of pestiviruses in black goats was not significantly higher on farms with cattle.

• Journal of fish pathology
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• v.28 no.2
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• pp.113-116
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• 2015

A $0.45-{\mu}m$ membrane filter is generally used to remove bacterial contamination during virus extraction from fish samples. However, the number of fish viruses is drastically reduced after filtration with a $0.45{\mu}m$ filter. In this study, we investigated the effect of filters on virus infectivity titer and the change in virus titer and bacterial number following different centrifugation conditions to determine a suitable procedure for virus extraction from fish samples. $10^{4.05}$ and $10^{5.05}TCID_{50}/ml$ of infectious hematopoietic necrosis virus (IHNV) and $10^{4.05}$ and $10^{4.55}TCID_{50}/ml$ of Oncorhynchus masou virus (OMV) were not detectable after filtration with two types of $0.45-{\mu}m$ filters, except the IHNV titer was reduced by about 10 fold after filter use (company A). No significant difference was found in the virus titer following centrifugation at $880{\times}g$ (30 min) or $3,500{\times}g$ (30 min), whereas IHNV and OMV titers were reduced by about 10 and 10-1000 fold by centrifugation at $14,000{\times}g$ (30 min) and $14,000{\times}g$ (10 and 30 min), respectively. A total of 97.7-99.9% Escherichia coli were eliminated by centrifugation at $880 {\times}g$ (30 min) and $3,500{\times}g$ (30 min). These results show that fish viruses were affected by filtering, even though the effect differed by virus species and filter type. Therefore, centrifugation at $3,500{\times}g$ (30 min) and use of medium with antibiotics may be useful for virus extraction along with a reduction in bacteria.