• Korean Journal of Veterinary Research
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• v.26 no.1
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• pp.97-102
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• 1986

The prevalence of diarrhea caused by enterotoxigenic Escherichia coli was surveyed on 445 calves in 6 farms which were located in the central part of Korea. The incidence of enterotoxigenic Escherichia coli in calves with diarrhea was investigated by detecting the K99 and F41 antigens from the isolated strains of Escherichia coli The incidence of colibacillosis in calves was 23.3%. Of 238 strains of Escherichia coli isolated from calves with diarrhea, 73 strains(30.6%) were proved possessing the K99 antigen by mannose-resistant hemagglutination(MRHA) using horse red blood cells and 79(33.1%) possessing F41 antigens by MRHA using guinea-pig red blood cells. The minca medium, nutrient broth, tryptic soy broth and brain heart infusion were tested for yield of K99 and F41 pili. The production of pili was greatest in minea medium. The best detachment method of the K99 and F41 pili from the cells was heat treatment for 20 minutes at $60^{\circ}C$ and concentration by precipitation with ammonium sulfate. The purified antigens of K99 and F41 were polypeptides with molecular weights of 18,500 and 29,500, respectively by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

• Korean Journal of Veterinary Service
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• v.35 no.3
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• pp.175-182
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• 2012

Rotaviruses have been known to be a major etiological agent of gastroenteritis in both infants and young animals. Subsequently new rotaviruses, which were morphologically indistinguishable but antigenically and electrophoretically distinct with each other, were reported from several animals throughout world including Korea. These new rotaviruses were named as non-group A or group B or group C rotaviruses and so on. It has been very difficult to isolate and grow the non-group A rotaviruses in vitro, and this has greatly limited the characterizations of non-group A rotaviruses and serological studies. In this study, monoclonal antibodies (MAbs) against porcine non-group A rotavirus were produced and characterized. The VP6 gene of porcine group C rotavirus Korean isolate(#06-52-1) was cloned and expressed. For expression of VP6 gene, baculovirus expression system was applied. The VP6 gene and expressed protein in the recombinant virus were confirmed by polymerase chain reaction (PCR), indirect fluorescence antibody (IFA) test and Western blot, respectively. The expressed VP6 was used for MAbs production. The MAbs produced in this study would be promising as diagnostic reagents for detection of group C rotavirus infection.

• Animal Bioscience
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• v.34 no.9
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• pp.1552-1558
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• 2021

Objective: This work was carried out to evaluate the effects of zilpaterol hydrochloride (ZH) and ractopamine hydrochloride (RH) combined with immunocastration on the welfare traits of feedlot Nellore cattle. Methods: Ninety-six Nellore males (average body weight [BW] = 409±50 kg; average 20 mo of age) were divided into two groups according to BW; half of the animals in each group received two doses of an immunocastration (ImC) vaccine in a 30 day interval, and the other half did not receive the vaccine (NoC). Afterward, the animals were housed and fed a common diet for 70 days. Then, they were split into three groups and fed one of the following diets for 30 additional days: control (CO) diet, with no β-AA; ZH diet, containing 80 mg/d ZH; and RH diet, containing 300 mg/d RH. Welfare traits were assessed by monitoring body surface temperature using infrared thermography (IRT) and plasma cortisol and temperament measurements. Results: There was no interaction between sexual condition and diet for any trait. The ImC and NoC groups did not differ in rectal and ocular temperatures. The ImC animals had higher flight speeds (p = 0.022) and tended to have higher cortisol levels (p = 0.059) than the NoC animals. Animals fed ZH and RH did not differ in cortisol levels, respiratory rate, rectal temperature, temperature measured by IRT, or temperament behaviour. Conclusion: The ImC animals showed a less stable temperament during handling practices than NoC, whereas ZH and RH supplementation had no adverse effects on animal welfare.

• Journal of fish pathology
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• v.37 no.1
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• pp.71-78
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• 2024

Streptococcosis, caused by Streptococcus iniae and Streptococcus parauberis is an important bacterial disease that affects in olive flounder in Korea. In Korea, multivalent bacterial vaccines are used to prevent streptococcal diseases in aquaculture. In this study, commercial vaccines containing formalin-inactivated bacterial cells of S. iniae and S. parauberis were administered at six fish farms and one unvaccinated fish farm were designated for investigation (Wando; 4 sites and Jeju; 3 sites). Blood was collected from vaccinated and unvaccinated olive flounders, and titers of antibodies against S. iniae and S. parauberis in serum were analyzed using ELISA. After a one shot vaccination in the farms at Jeju (farm A) and Wando (farm D), the proportion of individuals with specific antibodies against S. parauberis OD values of 0.4 or higher was 60% and 53.5%, respectively. But after booster vaccination, the proportion of individuals with serum OD values of 0.4 or higher was higher substantially increased to 96.6% (farm A) and 100% (farm D). The levels of S. parauberis specific antibodies of olive flounder were increased after vaccination in three fish farms (farm D, E, and F), but not S. iniae specific antibodies.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.2
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• pp.103-114
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• 1989

Reciprocal crosses were conducted between three strains of Taiwan Country chickens, developed in the National Chung-Hsing University, and two strains of Single Comb White Leghorns, developed in the Taiwan Livestock Research Institute. Traits studied were growing performances, laying performances, egg quality traits and traits concerning disease resistance, including resistance to Marek's disease virus and immune responses to Newcastle disease virus vaccine and to sheep red blood cell. Results indicated that laying performances of Taiwan country chickens were much inferior to White Leghorns, but they matured earlier, their eggs had better shell strength and larger proportion of yolk, and their general disease resistance was much better than White Leghorns. Heterosis were found in laying performances and egg quality traits. The heterosis in laying traits was so large that the hybrid laid as many eggs and as large eggs as did pure strains of White Leghorns. Strategies on the improvement of native chickens and the utilization of genetic merits of native chickens were also discussed.

• Microbiology and Biotechnology Letters
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• v.33 no.2
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• pp.142-147
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• 2005

The objective of this study was to develop a new potent antibacterial compound against bovine pneumoniae bacteria from medicinal plants or herbs. Among 65 kinds of medicinal plants and herbs, ethanol extracts of Citrus unishiu showed the highest solid yield of $54\%$. However, ethanal extracts from Agastache rugosa had the highest antibacterial activities against bovine pneumoniae bacteria, Mannheimia haemolytica A and Haemophilus somnus (size of clear zone: 16.0 mm and 10.0 mm, respectively). The antibacterial compound was also maximally extracted when the powder of A. rugosa was treated with $70\%$ ethanol at $45^{\circ}C$ for 12 hours.

• Korean Journal of Veterinary Research
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• v.59 no.3
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• pp.157-160
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• 2019

The production of rmtB-encoded 16S rRNA methylases has emerged as a novel mechanism promoting high-level resistance toward aminoglycosides in Gram-negative bacteria. Between 2015 and 2017, 636 distinct commensal Escherichia (E.) coli isolates were collected from different farms in South Korea to determine the prevalence and molecular characteristics of rmtB. The positive rates of rmtB between all the isolates and amikacin-resistant isolates were 1.1 and 100%, respectively. High-level aminoglycoside resistance could be transferred by conjugation from rmtB-positive donors to higher amikacin-resistance efficacies. This is the first report of 16S rRNA methylase-encoding genes in E. coli isolated from food-producing animals in Korea.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.45-45
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• 2023

Autophagy contributes to enhancing the immune system (innate and adaptive immune system) against foreign pathogens. Autophagy of macrophages is used as a major indicator for developing vaccine adjuvants to increase the adaptive immune response. In this study, RAL increased the production of immunostimulatory mediators and phagocytotic activity in RAW264.7 cells. RAL increased p62/SQSTM1 expression. Inhibition of TLR4, JNK, and PI3K/AKT blocked RAL-mediated increase of p62/SQSTM1. RAL activated JNK and PI3K/AKT signaling. RAL-mediated activation of JNK and PI3K/AKT signaling was reversed by TLR4 inhibition. Taken together, it is believed that RAL-mediated autophagy may be dependent on activating via TLR4-dependent activation of JNK and PI3K/AKT signaling in macrophages.

• Tuberculosis and Respiratory Diseases
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• v.57 no.2
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• pp.125-131
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• 2004

Tuberculosis (TB) remains an enormous global health problem, and a new vaccine against TB more potent than the current inadequate BCG vaccine is urgently needed. We constructed three recombinant Mycobacterium bovis BCG (rBCG) strains over-expressing antigen (Ag) 85A, Ag85B, or both of M. tuberculosis using their own promoter and secretory sequence, or hsp60 promoter. SDS-PAGE analysis of rBCG proteins showed overexpression of Ag85A and Ag85B proteins in higher level than of those in their parental strain of BCG. In addition, rBCG(rBCG/B.FA) over-expressing Ag85A and Ag85B induced strong IFN-${\gamma}$ production in splenocytes. However, there was no significant difference in protective efficacy between rBCG and their parental BCG strain. In this study, therefore, rBCG over-expressing Ag85A, Ag85B, or both failed to show enhanced protection against M. tuberculosis infection in a mouse model.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.61-68
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• 2003

Streptococcus mutans is known to be a major causative organism of human dental caries. The development of a vaccine against dental caries involves identification of appropriate antigens of mutans streptococci against which protective immune responses can be mounted, and the selection of a method of immunization that will generate sustained levels of protective antibodies. Antigens receiving most attention include streptococcal surface proteins that are involved in attachment to tooth surfaces and glucosyltransferases (GTF) that synthesize adhesive glucans from sucrose. The induction of antibody responses to orally administered antigens is often difficult due to digestive destruction of antigens and immune tolerance. Here we report the induction of antibody responses to an anti-caries vaccine containing retinoic acid (RA). Subcutaneous immunization with formalin-fixed bacteria or GTF supplemented with RA induced higher serum IgM and IgA responses to GTF compaired to oral adminstration. Antisera induced by Ingbritt strain showed partial cross-reaction with LM-7 strain, but not with OMZ175. These results suggest that subcutaneous immunization with GTF combined with an immunomodulator, RA, may be applied to anti-caries vaccine.