• Journal of Life Science
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• v.28 no.5
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• pp.555-562
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• 2018

Swine influenza virus (SIV) causes one of the most common diseases of the pig population, and its subtypes are determined by hemagglutinin (HA) and neuraminidase (NA). Recently, the SIV subtype diagnosis has been developed. The method using antigen-antibody reaction rather than PCR was mainly used because of the large change in the ribonucleotide sequences of SIV. Here, we have developed 10 diagnostic primer sets through multi-nucleotide sequences alignment of spreaded SIV since 2008 in Korea and then optimized the reaction of the one-step RT-PCR for rapid determination of SIV subtype. In addition, specific primers were designed to early determine the pandemic SIV by detecting unique M sequences proven in highly infectious and virulent subtypes of the influenza H1N1 (pH1N1). Here, some of the SIVs spread in Korea from 2008 to 2014 have been tested to determine the subtypes and pandemic potential of SIV. All diagnostic primer sets were found to be able to accurately determine the SIV subtype and to detect the pandemic SIV. In conclusion, it was confirmed that the optimized one-step RT-PCR analysis using these primer sets is useful for rapid diagnosis of SIV subtypes. These results can be used for development of SIV subtype diagnostic kit to early detect before virulent SIV spreads do.

• Journal of Food Hygiene and Safety
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• v.18 no.3
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• pp.118-124
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• 2003

For the rapid detection of various pathogenic microorganisms from food sample, various kinds of kits have been developed and commercially available in the markets. With the advantages of speed, accuracy and easiness, the market of these kits has gradually increased for the QC and QA field of food company as well as testing facilities or laboratories. In this study, the characteristics such as the detection limit and the sensitivity of immunochromatographic type of rapid detection kit (Donga Co, Korea, D-kit) for E. coli 0157:H7 developed by monoclonal antibody were examined and also the possibility of application of the kit to food samples was evaluated. The reference kits used for comparison study were Reveal E. coli 0157:H7 (Neogen Co., USA, R-kit) and VIP EHEC kit (Biocontrol Inc., USA, V-kit) occupying major market share. In the detection limit test with the E. coli 0157:H7 reference, both R-kit and D-kit showed a distinct positive reaction in $10^4$/ml and weak positive reaction in $10^3$/ml, whereas V-kit showed a same reaction in 105/ml. Also, it was identified that the culture treated with heat showed more sensitivity than no heat treated culture. The sensitivity test was conducted against 22 isolates of E. coli 0157:H7, 7 strains of non-O157:H7 verotoxin-producing E. coli, 40 strains of E. coli with different O and H antigen type, and 38 strains of non-E. coli Enterobacteriaceae, and all of the test strains except three were showed exactly three were showed exactly the same reaction against three kinds of the tested kits. All the three kinds of kits showed a positive reaction against E. coli O157:H19, E. coli O148:H18 and Salmonella galinarium. We suppose that there might be a similarity in serological property between these three strains and O157:H7. From the test results, it can be concluded that there is (was) no difference between the D-kit developed in this study and R-kit or V-kit based on the detection limit and sensitivity.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.6
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• pp.835-841
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• 2018

Objective: The aim of this study was to investigate the reversibility and safety of KISS1 metastasis suppressor (KISS1) gene vaccine in immunocastration. Methods: Six eight-week old ram lambs were randomly divided into vaccinated and control groups. The vaccine (1 mg/ram lamb) was injected at weeks 0, 3, and 6 of the study. Blood samples were collected from the jugular vein before primary immunization and at weeks 2, 4, 6, 10, 14, 22, and 30 after primary immunization. All ram lambs were slaughtered at 38 weeks of age, and samples were collected. Results: The specific anti-KISS1 antibody titers in vaccinated animals were significantly higher and the serum testosterone level was significantly lower than those in the control groups from week 4 to 14 after primary immunization (p<0.05). No significant difference was observed at weeks 22 and 30 after the primary immunization. Similar results were also found for scrotal circumference, testicular weight, length, breadth, and spermatogenesis in seminiferous tubules in week 30 after primary immunization. KS (KISS1-hepatitis B surface antigen S) fusion fragment of KISS1 gene vaccine was not detected in host cell genomic DNA of 9 tissues of the vaccinated ram lambs by polymerase chain reaction. Conclusion: The effects of KISS1 gene vaccine in immunocastration were reversible and no integration events were recorded.

• Journal of Preventive Medicine and Public Health
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• v.28 no.2 s.50
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• pp.526-541
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• 1995

This study was conducted to estimate the validity of reverse transcriptase-polymerase chain reaction(RT-PCR) compared to enzyme immunoassay(EIA) for the detection of hepatitis C virus (HCV) infection. EIA for antibody to HCV(anti-HCV) and RT-PCR for HCV was executed on the subjects from Pusan and Kyungnam area with questionnaire survey to collect some relating factors of HCV infection. As the result from 617 cases, the prevalence of HCV infection was 1.5% by EIA and 3.7% by RT-PCR(p<0.05), and the age standardized rate was 1.7% and 3.4% by EIA and RT-PCR, respectively. The prevalence of hepatitis B surface antigen(HBsAg) was 6.8% by enzyme linked immunosorbent assay(ELISA) and the age standardized rate was 7.7%. It was the higher in male group comparing to female group(p<0.01). Both of the prevalence of HCV and HBsAg were higher in elevated asparate aminotransferase(AST) and alanine aminotransferase (ALT) group than in normal AST and ALT group(p<0.01). There was no specific risk factor of HCV infection. Though the degree of agreement of EIA and RT-PCR by gamma statistics was 97.2%, it showed a significant difference between the two methods(p<0.01). For the detection of HCV infection, positive predictive value of EIA was 66.7% and negative predictive value of EIA was 97.2%. This study suggests that negative result to anti-HCV by EIA didn't mean the free state of HCV infection, therefore it would be helpful that further monitoring for HCV infection by RT-PCR in the case of elevated AST and ALT and/or clinically suspected.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.10
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• pp.1539-1545
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• 2007

An experiment was conducted using 20 male buffalo calves to study the effect of vitamin E and selenium supplementation on their immune response and plasma ${\alpha}$-tocopherol and selenium status. These buffalo calves (10-12 months old, average body weight $75.30{\pm}2.20 $ kg) were randomly allotted to four treatments on the basis of their body weights and were fed on wheat straw and concentrate mixture to meet their nutrient requirements of 500 g/d body weight gain. The buffalo calves were fed either a control diet (neither supplemented with Se nor VE) or diets supplemented with Se at 0.3 ppm (+Se), DL-alpha tocopheryl acetate at 300 IU (+VE), and both DL-alpha tocopheryl acetate at 300 IU and Se at 0.3 ppm (+Se+VE). These experimental diets were fed for 180 days. Blood samples were collected at day 0 and subsequently at 45 day intervals up to 180 days of experimental feeding to monitor plasma ${\alpha}$-tocopherol and Se concentrations. To assess humoral immune response, all calves were sensitized with formalin inactivated Pasteurella multocida antigen at 135 days of experimental feeding and blood was collected on 0, 7, 14, 21 and 28 days post vaccination (DPV) to measure antibody production using indirect ELISA. Cell mediated immune response of calves was assessed after 180 days of experimental feeding by in vivo delayed type hypersensitivity (DTH) reaction using phytohaemaglutinin-P (PHA-P) as a mitogen. Results revealed that feeding of VE and Se improved the plasma levels of these nutrients. Plasma levels of Se were affected by supplementation of both VE (p<0.001) and Se (p<0.001); however, no interaction ($Se{\times}VE$) was observed. Supplementation of Se improved the humoral immune response (p<0.008), whereas, VE showed a tendency towards improvement in cell mediated immune response (p<0.064). It was concluded that vitamin E and Se supplementation improved the status of these micronutrients and humoral immune response in buffalo calves.

• Journal of Life Science
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• v.30 no.8
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• pp.731-741
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• 2020

Coronavirus disease 19 (COVID-19) is caused by SARS-CoV-2 (Severe Acute Respiratory SyndromeCoronavirus 2). To date, seven coronaviruses that can infect humans were reported. Among them, infections with four coronavirus strains (HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1) resulted in mild symptoms such as common cold, whereas SARS-CoV and MERS-CoV caused severe symptoms and epidemics in 2002 and 2012, respectively. In the most recent, SARS-CoV-2 was first reported in Wuhan, China in December 2019 and became a notorious cause of the ongoing global pandemics. To diagnose, treat, and prevent COVID-19, the development of rapid and accurate diagnostic tools, specific therapeutic drugs, and safe vaccines essentially are required. In order to develop these powerful tools, it is prerequisite to understand a phenotype, a genotype, and life cycle of SARS-CoV-2. Diagnostic techniques have been developing rapidly around world and many countries take the fast track system to accelerate approval. Approved diagnostic devices are rapidly growing facing to urgent demand to identify carriers. Currently developed commercial diagnostic devices are divided into mainly two categories: molecular assay and serological & immunological assay. Molecular assays begins the reverse transcription step following polymerase chain reaction or isothermal amplification. Immunological assay targets SARS-CoV-2 antigen or anti-SARS-CoV-2 antibody of samples. In this review, we summarize the phenotype, genome structure and gene expression of SARS-CoV-2 and provide the knowledge on various diagnostic techniques for SARS-CoV-2.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.9-22
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• 1996

Respiratory Syncytial virus (RSV) is an important cause of acute lower respiratory tract infections in human, with infants and young children being particularly susceptible. In the temperate zones, sharp annual outbreaks of RSV occur during the colder months, in both the northern and the southern hemisphere. RSV is unusual in that it can repeatedly reinfect individuals throughout life and infect babies in the presence of maternal antibody. RSV isolates can be divided into two subgroups, A and B, on the basis of their reactions with monoclonal antibodies, and the two subgroups are also distinct at the nucleotide sequence level. The specific diagnosis of RSV infection was best made by isolation of virus in tissue culture, identification of viral antigen, or by specific serologic procedures. Recently, rapid detection of RSV and analysis of RSV strain variation became possible by development of methods of reverse transcription and polymerase chain reaction amplification. In this study, to determine the genetic diversity of RSV found in Korea, 173 bp and 164 bp spanning selected regions of the RSV F and SH genes were enzymatically amplified and sequenced, respectively. Eight for F gene and three for SH gene were detected in 66 nasopharyngeal swap samples tested. Two major antigenic subgroups, A and B were confirmed from Korean samples (seven for subgroup A and one for subgroup B). At the nucleotide level of the F gene region, Korean subgroup A strains showed 95-99% homologies compared to the prototype A2 strain of subgroup A and 93-100% homologies among Korean subgroup A themselves. For the SH gene region, Korean subgroup A strain showed 97.5% homology compared to the prototype A2 strain of subgroup A, and Korean subgroup B strain showed 97% homology compared to the prototype 18537 strain of subgroup B. Most of base changes were transition and occured in codon position 3, which resulted in amino acid conservation. Using the maximum parsimony method, phylogenetic analysis indicated that Korean RSV strains formed a group with other RSV strains isolated from the United States, Canada, the Great Britain and Australia.

• Korean Journal of Veterinary Research
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• v.46 no.4
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• pp.347-353
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• 2006

Serum samples of 30 chickens per flock from 6 grand parent stock (GPS) farms and 70 parent stock (PS) farms were collected for seroprevalent study of pullorum disease-fowl typhoid (PD-FT) infection by serum plate agglutination test (SPA). The incidence of PD-FT infection in GPS flocks and PS flocks were 0% and 15.7%, respectively. Especially PS flocks infected with PD-FT showed age dependent patterns that 22.2% of flocks between 20 to 30 weeks of age and 38.9% of flocks between 30 to 40 weeks of age were positive. The incidence of GPS flocks and PS flocks using Salmonella (S.) gallinarum 9R (SG9R) live vaccine were 33.3% and 58.6%, respectively. The sero-positive rate of 11 flocks were 6.7-83.3% by SPA and 2.9-55.6% by enzyme linked immunosorbent assay (ELISA), and ELISA showed more lower antibody levels than SPA. Furthermore, specific antibodies produced by SG9R vaccination were detectable by SPA using SG9R antigen without cross-reaction with the PD-FT infection.

• Korean Journal of Veterinary Service
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• v.26 no.2
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• pp.163-184
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• 2003

This study was conducted to survey the farm which suffered from disease similar to classical swine fever(CSF) in Gyeongbuk province. Clinical signs appeared first in a few number of growing pigs which showed specific signs of diarrhea, depression, sleepiness, and reluctance to get up or to eat. Younger piglets may have appeared chilled, shiver and huddle together. As the disease progresses the affected pig's skin went red and purple. In histopathological signs, there were many haemorrhages throughout the body and larger haemorrhages in some organs such as lymph nodes. And there is a precipitous fall in the number of circulating leukocytes in the blood. In spite of insisting of farmer which did not vaccinate to classical swine fever, significant antibody production was detected in these affected pigs at enzyme-linked immuonsorbent assay. According to the above results at first glance, these affected pig suspected with CSF in clinical signs and histopathological lesions only. Because the symptoms and post-mortem picture were very similar to CSF, these false positive results would have been dangerous to diagnostician. But by reverse transcriptase polymerase chain reaction(RT-PCR) and comparative nucleotide sequence analysis, the disease was correctly diagnosed with post-weaning multisystemic wasting syndrome(PMWS) and porcine reproductive and respiratory syndrome(PRRS) compoundly. And the antigen which were detected the lesion similar to CSF virus, was confirmed with LOM vaccine strain of CSF. In most national CSF eradication program and in countries which are free of the CSF virus, vaccination against CSF is not practiced and generally is not allowed. But now in Korea, routine vaccination is practiced because of outbreaking the CSF repeatedly. When CSF is diagnosed the whole herd and other in contact animal are slaughtered continuously.

• The Journal of the Korean Society for Microbiology
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• v.22 no.2
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• pp.175-184
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• 1987

The use of alkylating agent cyclophosphamide(CY), a widely used antitumor drug is well known as a potent immunosuppressant and has been used as a probe for investigating the functional capabilities of lymphocyte subsets of both T and B cells that play an important role in the regulation of the immune response. The present study was undertaken in an effort to assess the effects of CY on immunological memory in murine model. CY, given as a single dose of CY(250mg/kg) before sensitization with sheep red blood cells(SRBC) enhanced the primary response of Arthus and delayed-type hypersensitivity(DTH), as measured by footpad swelling reaction, but suppressed their tertiary DTH response. The similar CY pretreatment enhanced both the primary and tertiary hemagglutinin(HA) responses to SRBC, and the tertiary antibody response against polyvinylpyrroridone(PVP), a thymus-independent antigen but not the primary response against PVP. CY, given as a single dose of 250mg/kg 2 days before the primary immunization and two doses of 100mg/kg 2 days before the secondary and tertiary immunization, markedly suppressed the tertiary DTH and HA responses to SRBC. However, CY, given as small multiple daily doses(10mg/kg) over 4 days before sensitization but not after sensitization, enhanced the secondary HA response to SRBC. Contact sensitivity to dinitrofluorobenzene(DNFB) was suppressed by the drug, given either as a single large dose(300mg/kg) or as multiple dose(10mg/kg) administered 2 days before, together with or after DNFB sensitization. This suppression was more pronounced and more significant when CY was given as multiple dose. However, the enhancement of the secondary contact sensitivity to DNFB by CY was not clear-cut. The splenectomy appears to increase the enhancing effect of CY on contact sensitivity. These results suggest that CY selectively influences the immune response depending on the time of the drug administration relative to immunization and that the secondary or tertiary immune response involve memory cells with different susceptibilities to CY. Moreover, these results suggest that multiple low doses may sesectivley inhibit suppressor T cell proliferation involving DTH, HA or contact sensitivity without effecting helper T cells, but high doses presumably inhibit helper T cells and suppressor T cells with effecting B cells.