• Korean Journal of Veterinary Service
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• v.39 no.4
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• pp.231-237
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• 2016

The present study was conducted to investigate the lesion of red internal organs in slaughtered pigs and provided assistant data for pig farms. During March to December 2015, a total of 1,160 lung samples out of 58 herds were collected randomly from pigs slaughtered in Jeonbuk province. In addition, 290 hilar lymph nodes from pig with pneumonic lung lesion (5 samples per herd) were screened for selected viral and bacterial pathogens. Gross lesions of lungs such as swine enzootic pneumonia (SEP), pleuritis, pleuropneumonia, pericarditis and liver white spots were examined. The overall prevalence of SEP was 64.3% (746/1,160). In the analysis of seasonal prevalence, there was an increase of occurrence during the spring months (287/400, 71.8%) and decrease during the fall months (93/200, 46.5%) among the whole herds. The mean number of SEP score per pig was $1.20{\pm}1.28$. The prevalence of pleuropneumonia, pleuritis, pericarditis, and milk spot was 25.5% (296/1,160), 44.1% (512/1,160), 3.8% (44/1,160) and 17.6% (204/1,160), respectively. The most frequent region with lung lesion was diaphragmatic lobes (left 17.1%, right 17.3%). In the detection of viral pathogens by PCR, porcine circovirus type2 (PCV2) was positive in 86.9% (252/290), while porcine reproductive and respiratory syndrome virus (PRRSV) was not detected, In the case of bacterial pathogens, 50 microorganisms were isolated by PCR and/or microbiological test. The most frequently isolated bacteria was Streptococcus suis (20, 34.4%), followed by Pasteurella multocida (17, 29.3%), Streptococcus spp. (11, 3.4%), Actinobacillus pleuropneumoniae (2, 8.9%).

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.461-468
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• 2016

In recent years, various naturally occurring defence peptides such as plectasin have attracted considerable research interest because they could serve as alternatives to antibiotics. However, the production of plectasin from natural microorganisms is still not commercially feasible because of its low expression levels and weak stability. A tandemly arrayed plectasin gene (1,002 bp) from Pseudoplectania nigrella was generated using the isoschizomer construction method, and was inserted into the pPICZαA vector and expressed in Pichia pastoris. The selected P. pastoris strain yielded 143 μg/ml recombinant plectasin (Ple) under the control of the methanol-inducible alcohol oxidase 1 (AOX1) promoter. Ple was estimated by SDS-PAGE to be 41 kDa. In vitro studies have shown that Ple efficiently inhibited the growth of several gram-positive bacteria such as Streptococcus suis and Staphylococcus aureus. S. suis is the most sensitive bacterial species to Ple, with a minimum inhibitory concentration (MIC) of 4 μg/ml. Importantly, Ple exhibited resistance to pepsin but it was quite sensitive to trypsin and maintained antimicrobial activity over a wide pH range (pH 2.0 to 10.0). P. pastoris offers an attractive system for the cost-effective production of Ple. The antimicrobial activity of Ple suggested that it could be a potential alternative to antibiotics against S. suis and S. aureus infections.

• Korean Journal of Veterinary Service
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• v.44 no.4
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• pp.247-256
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• 2021

The recombinant lysozyme-HJL34 proteins were expressed and purified using commercial Escherichia (E.) coli expression system. Stx2e⁺ F18⁺ E. coli, Actinobacillus pleuropneumoniae (APP), Streptococcus (S.) suis, and Clostridium (C.) perfringens strains were isolated from pigs. The minimum inhibitory concentrations (MICs) of the recombinant lysozyme-HJP34 proteins were examined by means of the microtiter plate method, according to the NCCLS recommendations. The possibility of its as the alternatives to antibiotics was tested in piglets. The MICs were determined as 75 ㎍/mL, 300 ㎍/mL, 75 ㎍/mL, 35.5 ㎍/m against Stx2e⁺ F18⁺ E. coli, APP, S. suis, C. perfringens, respectively. A total of 25 piglets were divied 5 groups. The piglets in group A~C were fed with commercial feed and those in groups D, E were fed with commercial feedstuff. All piglets in groups B~E were challenged with virulent Stx2e⁺ F18⁺ E. coli, APP, S. suis strains. Groups C and D were treated with antimicrobial from 24 h after challenge. All piglets in group B died within 3 days after challenge. Among 5 piglets in groups C and D piglets, 80% survived after challenge. Among group E piglets, 60% were alive until the end of this study. Therefore, this study indicates that recombinant lysozyme-HJP34 proteins is a suitable possibility as a feed additive for reduction of diseases by bacterial pathogens in piglet feed.

• The Korean Journal of Community Living Science
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• v.23 no.4
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• pp.383-397
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• 2012

The incidence of zoonoses in Korea has recently increased. But the study for high risk group such as pig farmers to zoonoses has not been conducted in Korea. Thus we reviewed the articles in order to obtain basic data for zoonoses among pig farmers, especially in rural communities. Pigs are one of the most important domestic livestock in Korea not only from economic standpoint but also from standpoint of food. Pigs also represent a potential reservoir for many novel pathogens, therefore may transmit these to humans via direct contact, vectors such as mosquitos, or contaminated meat. The zoonoses associated with pigs can be classified into bacterial pathogen, viruses and so on. Bacterial zoonoses include brucellosis, leptospirosis, listeriosis, enterohemorrhagic Escherichia coli infection, pasteurellosis, salmonellosis, yersiniosis, tuberculosis, anthrax, necrobacillosis, swine erysipelas, erysipeloid, melioidosis, Streptococcus suis infection, Clostrium difficile infection, and campylobactor infection. Viral zoonoses consist of Japanese encephalitis, swine influenza, Nipah virus, Reston ebolavirus, and hepatitis E virus infection. Other type of zoonoses include actinomycosis, toxoplasmosis and Taenia solium infection. These zoonoses were important in Korean health policy but lately they have been overlooked. For effective health policy, we need to study zoonoses associated with pigs, and clinicians and veterinarians must care deeply about these zoonoses.

• Journal of Veterinary Clinics
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• v.11 no.2
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• pp.507-516
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• 1994

The purposes of this investigations were survey of the occurred bacterial diseases, development of new animal health drug, guidance to formers on the treatment and control methods of diseases. Some series of investigations have been carried out by microbiological, pathological and serological examinations. The results could be summarized as follows. 1. A total of 953 cases of outbreaked swine diseases have been diagnosed in Clinical pathology laboratories, Bayer Vet Res Institute during 8 years (from 1986 to 1993). The high incidence diseases were colibacillosis, pleuropneumonia, streptococcal infection and pasteurellosis in decreasing order. 2. Pleuropneumonia caused by Actinobacillus pleuropneumoniae was the most important respiratory diseases and pasteurellosis by Pasteurella multocide could be confirmed in several cases. 3. Actinobacillus pleuropneumoniae 50 strains were isolated and identified by biochemical and serological tests. In serotyping test, 22 isolated strains were serotype 5, 21 strains as serotype 2, each 2 strains as serotype 3 and 7 by the coagglutination test. 4. Colibacillosis and edema discase caused by Escherichia coli has been the most predominant outbreaked disease in this investigations. The 100 isolates of E coli strains were sensitive to amikacin, colistin, enrofloxacin, gentamycin and trimethoprim -sulfamethoxazole. 5. Swine erysipelas caused by Erysipelothrix rhusiopathiae was confirmed 25 cases as acute septicemic forms. Isolates of E rhusiopathiae were highly sensitive to ampicillin, cephalothin, enrofloxcin, penicillin and tetracycline. 6. The 49 cases of hemorrhagic and necrotic enteritis in piglets were observed and 13 strains of Clostridium perfringens could be isolated and confirmed by biological and serological test. Isolates of Clostridium perfringens type C were highly sensitive to ampicillin, cephalothin, enrofloxacin, penicillin and trimethoprim- sulfamethoxazole. 7. The 14 strains of Streptococcus suis type II could be isolated from meningitis of piplets. 8. Polyserositis caused by Haemophilus parasuis and salmonellosis were observed and confirmed. Also Corynebacterial infections and several parasitosis have been also observed in this investigations.

• Journal of Veterinary Science
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• v.24 no.1
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• pp.11.1-11.14
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• 2023

Background: Peripheral blood mononuclear cells (PBMCs) are commonly used to assess in vitro immune responses. However, PBMC isolation is a time-consuming procedure, introduces technical variability, and requires a relatively large volume of blood. By contrast, whole blood assay (WBA) is faster, cheaper, maintains more physiological conditions, and requires less sample volume, laboratory training, and equipment. Objectives: Herein, this study aimed to develop a porcine WBA for in vitro evaluation of immune responses. Methods: Heparinized whole blood (WB) was diluted (non-diluted, 1/2, 1/8, and 1/16) in RPMI-1640 media, followed by phorbol myristate acetate and ionomycin. After 24 h, cells were stained for interferon (IFN)-γ secreting T-cells followed by flow cytometry, and the supernatant was analyzed for tumor necrosis factor (TNF)-α. In addition, diluted WB was stimulated by lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid (poly I:C), reference strain KCTC3557 (RS), field isolate (FI), of heat-killed (HK) Streptococcus suis, and porcine reproductive and respiratory syndrome virus (PRRSV). Results: The frequency of IFN-γ⁺CD3⁺ T-cells and concentration of TNF-α in the supernatant of WB increased with increasing dilution factor and were optimal at 1/8. WB TNF-α and interleukin (IL)-10 cytokine levels increased significantly following stimulation with LPS or poly I:C. Further, FI and RS induced IL-10 production in WB. Additionally, PRRSV strains increased the frequency of IFN-γ⁺ CD4^-CD8⁺ cells, and IFN-γ was non-significantly induced in the supernatant of re-stimulated samples. Conclusions: We propose that the WBA is a rapid, reliable, and simple method to evaluate immune responses and WB should be diluted to trigger immune cells.