• Journal of Microbiology and Biotechnology
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• v.29 no.4
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• pp.651-657
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• 2019

Although smallpox was eradicated in 1980, it is still considered a potential agent of biowarfare and bioterrorism. Smallpox has the potential for high mortality rates along with a major public health impact, eventually causing public panic and social disruption. Passive administration of neutralizing monoclonal antibodies (mAbs) is an effective intervention for various adverse reactions caused by vaccination and the unpredictable nature of emerging and bioterrorist-related infections. Currently, vaccinia immune globulin (VIG) is manufactured from vaccinia vaccine-boosted plasma; however, this production method is not ideal because of its limited availability, low specific activity, and risk of contamination with blood-borne infectious agents. To overcome the limitations of VIG production from human plasma, we isolated two human single-chain variable fragments (scFvs), (SC34 and SC212), bound to vaccinia virus (VACV), from a scFv phage library constructed from the B cells of VACV vaccine-boosted volunteers. The scFvs were converted to human IgG1 (VC34 and VC212). These two anti-VACV mAbs were produced in Chinese Hamster Ovary (CHO) DG44 cells. The binding affinities of VC34 and VC212 were estimated by competition ELISA to $IC_{50}$ values of $2{\mu}g/ml$ (13.33 nM) and $22{\mu}g/ml$ (146.67 nM), respectively. Only the VC212 mAb was proven to neutralize the VACV, as evidenced by the plaque reduction neutralization test (PRNT) result with a $PRNT_{50}$ of ~0.16 mg/ml (${\sim}1.07{\mu}M$). This VC212 could serve as a valuable starting material for further development of VACV-neutralizing human immunoglobulin for a prophylactic measure against post-vaccination complications and for post-exposure treatment against smallpox.

• Korean Journal of Veterinary Service
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• v.29 no.3
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• pp.365-376
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• 2006

To identify immune response of leukocytes in peripheral blood of cattle vaccinated with an attenuated live Akabane virus vaccine, leukocytes were reacted with monoclonal antibodies which are specific to bovine lymphocyte surface antigens and assayed by the flow cytometry. Serum neutralizing (SN) test was used to measure antibody titers after vaccination, SN antibody was appeared to 7 days post-vaccination (PV) and 2-8 antibody titers were observed in 14 days PV. Proportion of $CD8^-$ MHC $class II^+$ expressing cells were rapidly increased at 3 days PV. $CD8^+$ MHC $class II^-$ cells were increased at 7 days PV. $CD4^+CD8^-,\;WC^+CD4^-,\;CD4^+CD8^+,\;WC1^-CD4^+, \;WC1^-CD8^+$, and $CD4^-CD8^+$ cells were highly increased at 3, 3, 7, 7, 14, 14 days PV, respectively.

• Korean Journal of Veterinary Service
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• v.23 no.1
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• pp.93-102
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• 2000

In this experiment, we studied the sero-positive rate of akabane virus in cattle from Jeju-do and analyzed the seroepidemiological features. In an analysis of 1,051 samples, the positive rate for neutralizing antibody in sera collected in nine regions on Jeju-do was 56.7%. The rate varied with the region. The positive rate was 69.6% in Aewol, 63.1% in Jeju city, 54.4% in Anduck, 51.0% in Hallim, 69.8% in Jocheun, 47.6% in Pyosun, 40% in Daejeong, 30.0% in Harkyung, 71.6% in Namwon, 24.5% in Sungsan, 133.,3% in Seokypo and 44.5% in Gujwa, respectively The rate also depended on the age of the cattle. The positive rate was 67.2% in calves 0- to 12-month old, 48.3% in cattle 13- to 24-month old, 65.4% in cattle 25- to 36-month old, and 65.4% in cattle more than ,B7 months old. To isolate the virus from calves with malformations including arthrogryposis and hydranencephaly, cerebral homogenates were inoculated into Vero cells, which were determined for cytopathic effect (CPE). Vero cells with CPE were examined for Akabane virus using an electron microscope (EM) and indirect immunofluorescent antibody test (EM). Typical virus particles with a width of 90-130nm and specific immunofluorescence in the cytoplasm of infected cells were sought for identification.

• Korean Journal of Veterinary Service
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• v.46 no.4
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• pp.335-338
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• 2023

The COVID-19 pandemic, triggered by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has not only impacted human health on a global scale but also raised concerns about the vulnerability of a wide array of animals that are in close contact with humans. Particularly, the potential for infection and the subsequent immune response in domestic pets such as dogs and cats remain largely unexplored under natural living conditions. In this study, we have undertaken the task of detecting and tracking the presence of antibodies against SARS-CoV-2 in a small cohort of household pets-specifically, two dogs and two cats. Employing techniques such as the indirect ELISA and plaque reduction neutralization tests, we observed that the neutralizing antibodies against SARS-CoV-2 in these animals were maintained for a duration of up to six months following their initial positive test result. This duration mirrors the antibody response documented in human cases of COVID-19, suggesting a comparable post-infection immune response timeline between humans and these domestic animals.

• Journal of Veterinary Clinics
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• v.11 no.2
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• pp.585-592
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• 1994

A consecutive Jiao Chio acupuncture therapy was performed for 3 days in the 45-90 days old 11 calves of which have been shown severe watery diarrhea. The discharge of the infected calves was yellowish brown in color. Two calves of these patients were infected wi pulmonary disease as well as diarrhea. Thus, Su Qi and Fei Yu acupuncture therapy was carried out additionally after dosing with antibiotics twice for The two infected calves. Blood chemical values and serum neutralizing antibody titers were checked, and total blood cell count was also carried out to know the therapeutic effect before and after(21 days) acupuncture therapeutics. The results are as follows ; 1, The diarrhea has ceased one day after begining of the acupuncture therapy in 5 calves, and the cessation of the diarrhea in remaining calves occurred in 1 calf each on 3rd and 4th day, and 2 calves on 6th day, respectively. Two calves infected with pulmonary disease as well diarrhea were cured 8 days after the begining of the therapcutics. 2. Rotaviruses wire detected in the feces of 2 calves, and bovine diarrhea viruses were detected in the 8 calves by the test for serum neutralizing antibody titers, and bovine coronaviruses were also detected in 5 calves. Four calves of the 5 bovine coronavirus infected calves were also infected with bovine diarrhea viruses. 3. Total leucocyte number, total amount of serum protein, and amount of fibringen were slightly increased, while total erythrocyte number, and erythrocyte packed cell volume were slightly decreased. These valucs were statistically not significant. Electrolytes of Na/sup +/, K/sup +/ and Cl/sup -/ were slightly decreased but these values also were not significant. These results indicate that the acupuncture therapeutics arc significantly effective to remove the viral diarrhea in the young calves.

• IMMUNE NETWORK
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• v.21 no.6
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• pp.39.1-39.18
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• 2021

The high virulent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that emerged in China at the end of 2019 has generated novel coronavirus disease, coronavirus disease 2019 (COVID-19), causing a pandemic worldwide. Every country has made great efforts to struggle against SARS-CoV-2 infection, including massive vaccination, immunological patients' surveillance, and the utilization of convalescence plasma for COVID-19 therapy. These efforts are associated with the attempts to increase the titers of SARS-CoV-2 neutralizing Abs (nAbs) generated either after infection or vaccination that represent the body's immune status. As there is no standard therapy for COVID-19 yet, virus eradication will mainly depend on these nAbs contents in the body. Therefore, serological nAbs neutralization assays become a requirement for researchers and clinicians to measure nAbs titers. Different platforms have been developed to evaluate nAbs titers utilizing various epitopes sources, including neutralization assays based on the live virus, pseudovirus, and neutralization assays utilizing recombinant SARS-CoV-2 S glycoprotein receptor binding site, receptor-binding domain. As a standard neutralization assay, the plaque reduction neutralization test (PRNT) requires isolation and propagation of live pathogenic SARS-CoV-2 virus conducted in a BSL-3 containment. Hence, other surrogate neutralization assays relevant to the PRNT play important alternatives that offer better safety besides facilitating high throughput analyses. This review discusses the current neutralization assay platforms used to evaluate nAbs, their techniques, advantages, and limitations.

• Korean Journal of Veterinary Service
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• v.23 no.4
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• pp.349-360
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• 2000

An epidemiological survey was conducted to investigate fowl typhoid outbreaks in Kyungnam province of Korea. The causative agent, salmonella gallinarum was isolated from 68 chicken samples of tentatively diagnosed fowl typhoid cases occurred during the period from January 1996 to September 1999. Comparative studies were also carried out to evaluate the diagnostic methods for detection of S gallinam The results obtained were as follows; 1. Of the 68 cases of tentatively diagnosed fowl typhoid, 56 (82%) cases were determined as fowl typhoid by biochemical test and pathological findings. The other 12 (18%) cases were determined as paratyphoid. 2. Fowl typhoid outbreaks occur continuously all seasons in the year, however the incidence was remarkably increased from May to September. 3. The frequency of incidence of fowl typhoid in terms of regional distribution was relatively high in egg-laying hens facilities, and the mode of transmission is likely to be either egg-to-egg or lateral transfer by wild birds or rats. 4. All of 18 isolates from 56 cases were identified as S gallinarum by biochemical and serological test. 5. Antimicrobial drug susceptibility test against 18 isolates showed that the isolates were highly susceptible to ASH, CZ, CF and GM (above 90%), whereas those strains were 100% resistant to EM, NA and PC. 6. S gallinarum rfbS gene was targeted to be amplified by PCR for comparative detection of S gallinarum in the experimentally infected chickens. The amplified 720bp DNA fragment, which is specific in D serogroup strains of S enterica subspecies was confirmed by agarose gel electrophoresis. 7. A comparison made between fecal culture and PCR-method revealed that later-method was relatively higher in detection rate than that of former method for S gallinarum. 8. Comparison of currently applied methods, rapid serum agglutination test (RST) and microplate agglutination test (MAT), with experimentally infected chickens were made to evaluate sensitivity of detection by neutralizing antibody titration. Both methods detected neutralizing antibodies from the challenged chickens of 5 day post infection. However, positive reactions were determined after 7 and 9 days post infection by MAT and RST, respectively.

• Korean Journal of Veterinary Service
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• v.32 no.3
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• pp.201-207
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• 2009

Porcine transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV) and rotaviruses are considered as the most important causative agents of diarrhea in piglets. The study established 3 method vaccination programs to prevent PEDV. A (LL)group inoculated twice vaccinations on 2-weeks-interval during the late term of pregnant sows with PEDV live vaccine. The B (LKK) group was applied that one time single PEDV live vaccine at the pre-mate followed by the TGEV PEDV combined inactivated vaccine (twice vaccination on 2-weeks interval at the third-trimester). C (KK) group was applied to sow which inoculated twice vaccination on 2-weeks-interval during the late term of pregnant sows with by the TGEV, PEDV combined inactivated vaccine. As the result of SN test on sows in the pig farm before vaccination, antibody titers was showed 9/45 (20.0%). By comparison with the serum neutralizing antibody titers against PEDV of the vaccination programs after PEDV of the vaccination, A group and B group vaccination method was higher than those of C group in sows. In the piglets up to 2 weeks of age, A group was showed antibody titers of 17/22 (81.8%) that showed 2-128, and B group was showed antibody titers of 30/37 (81.1%) that showed 2-512, and C group was showed antibody titers of 14/28 (50.0%) that showed 2-32. On the other hand, PEDV antibody titers were tested for the survey. As the results of SN test, Aujeszky's disease survey in 54 pig farms from november 2005 to august 2006, antibody titers of 47/286 (16.4%) showed above 2. Five breeding farms were antibody titers of 38/77 (49.4%), Wanggung zone farms antibody titers of 59/85 (69.4%). In pigs farms vaccinated the first of twice PEDV live vaccine, and after 6 month, the second of twice TGEV PEDV combined inactivated vaccine (LLKK, 256-1024 titer) method was higher than those of vaccinated twice the early term of pregnant, and twice the late term of pregnant sows of PEDV live vaccine (LLLL, 32 titer).

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.718-724
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• 2017

The combination of rabies immunoglobulin (RIG) with a vaccine is currently effective against rabies infections, but improvements are needed. Genetic engineering antibody technology is an attractive approach for developing novel antibodies to replace RIG. In our previous study, a single-chain variable fragment, scFv57R, against rabies virus glycoprotein was constructed. However, its inherent weak stability and short half-life compared with the parent RIG may limit its diagnostic and therapeutic application. Therefore, an acidic tail of synuclein (ATS) derived from the C-terminal acidic tail of human alpha-synuclein protein was fused to the C-terminus of scFv57R in order to help it resist adverse stress and improve the stability and half-life. The tail showed no apparent effect on the preparation procedure and affinity of the protein, nor did it change the neutralizing potency in vitro. In the ELISA test of molecular stability, the ATS fusion form of the protein, scFv57R-ATS, showed an increase in thermal stability and longer half-life in serum than scFv57R. The protection against fatal rabies virus challenge improved after fusing the tail to the scFv, which may be attributed to the improved stability. Thus, the ATS fusion approach presented here is easily implemented and can be used as a new strategy to improve the stability and half-life of engineered antibody proteins for practical applications.

• Journal of Veterinary Science
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• v.21 no.4
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• pp.63.1-63.9
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• 2020

Background: Canine adenovirus type 2 (CAV-2) induces infectious laryngotracheitis in members of the family Canidae, including dogs. To date, no ELISA kits specific for CAV-2 antibody have been commercialized for dogs in Korea. Objectives: We aimed to develop new indirect enzyme-linked immunosorbent assay (I-ELISA) to perform rapid, accurate serological surveys of CAV-2 in dog serum samples. Methods: In total, 165 serum samples were collected from dogs residing in Chungbuk and Gyeongbuk provinces between 2016 and 2018. The Korean CAV-2, named the APQA1701-40P strain, was propagated in Madin-Darby canine kidney cells and purified in an anion-exchange chromatography column for use as an antigen for I-ELISA. The virus-neutralizing antibody titers of CAV-2 in the dog sera were measured by virus neutralization (VN) test. Results: We compared the results obtained between the VN and new I-ELISA tests. The sensitivity, specificity, and accuracy of new I-ELISA were 98.6%, 86.4% and 97.0% compared with VN test, respectively. New I-ELISA was significantly correlated with VN (r = 0.91). Conclusions: These results indicate that new I-ELISA is useful for sero-surveillance of CAV-2 in dog serum.