• Korean Journal of Veterinary Service
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• v.32 no.4
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• pp.299-306
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• 2009

Assay for the detection and quantification of porcine circovirus type 2 (PCV 2) with the real-time PCR were developed. TaqMan probe real-time using a set of primer/probe was developed for detection of PCV 2. In this study we applied real-time PCR assay to 320 samples, collected from pig farms. In 151 of 320 samples, PCV 2 DNA was detected by conventional PCR assay. All samples positive for PCV 2 DNA in conventional PCR assay were also positive in Real-time PCR assay, but 69 of 169 samples that tested negative for PCV 2 DNA in conventional assay were tested positive in TaqMan probe real-time PCR assay. The test of TaqMan probe real-time PCR resulted in detection and quantification limits of 101 copies per sample. TaqMan probe real-time PCR assay increased the number of samples in which PCV 2 was detected by 21%. TaqMan probe real-time PCR assay is very efficient method in contrast to the conventinal PCR, becoming increasingly important method for gene analysis.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1489-1495
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• 2002

Five regions and 258 pigs were selected for this study: North (Beijing), Central (Wuhan), South (Guangzhou), Southwest (Chongqing), Northeast (Harbin). Five typical genetics of growing-finishing pig were selected: Landrace${\times}$Large White${\times}$Beijing Black, Duroc${\times}$Landrace${\times}$Large White, Duroc${\times}$Large White${\times}$Landrace, Landrace${\times}$Rongchang, Landrace${\times}$Harbin White, respectively at each sites. The basal diet was a corn-soybean meal containing sufficient nutrients to meet requirements. Carcass fat-free lean gain was determined by dissecting and analyzing chemical composition of the carcass. Cubic function fitted lean moistures to live weights better than other functions. Exponential function fitted lean lipids to live weights equally to allometric function. Carcass fat-free lean gain of Duroc${\times}$Large White${\times}$Landrace, Landrace${\times}$Large White${\times}$Beijing Black, Duroc${\times}$Landrace${\times}$Large White, Landrace${\times}$Harbin White, Landrace${\times}$Rongchang from 20 to 100 kg of average body weight was 259 g/d, 261 g/d, 311 g/d, 220 g/d, 200 g/d, respectively. All are lower than intermediate fat-free lean gain in NRC (1998).

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1229-1238
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• 2016

This study was conducted to determine the relationships of five intragenic single nucleotide polymorphism (SNP) markers (protein kinase adenosine monophosphate-activated ${\gamma}3$ subunit [PRKAG3], fatty acid synthase [FASN], calpastatin [CAST], high mobility group AT-hook 1 [HMGA1], and melanocortin-4 receptor [MC4R]) and meat quality traits of Duroc breeding stocks in Korea. A total of 200 purebred Duroc gilts from 8 sires and 40 dams at 4 pig breeding farms from 2010 to 2011 reaching market weight (110 kg) were slaughtered and their carcasses were chilled overnight. Longissimus dorsi muscles were removed from the carcass after 24 h of slaughter and used to determine pork properties including carcass weight, backfat thickness, moisture, intramuscular fat, $pH_{24h}$, shear force, redness, texture, and fatty acid composition. The PRKAG3, FASN, CAST, and MC4R gene SNPs were significantly associated with the meat quality traits (p<0.003). The meats of PRKAG3 (A 0.024/G 0.976) AA genotype had higher pH, redness and texture than those from PRKAG3 GG genotype. Meats of FASN (C 0.301/A 0.699) AA genotype had higher backfat thickness, texture, stearic acid, oleic acid and polyunsaturated fatty acid than FASN CC genotype. While the carcasses of CAST (A 0.373/G 0.627) AA genotype had thicker backfat, and lower shear force, palmitoleic acid and oleic acid content, they had higher stearic acid content than those from the CAST GG genotype. The MC4R (G 0.208/A 0.792) AA genotype were involved in increasing backfat thickness, carcass weight, moisture and saturated fatty acid content, and decreasing unsaturated fatty acid content in Duroc meat. These results indicated that the five SNP markers tested can be a help to select Duroc breed to improve carcass and meat quality properties in crossbred pigs.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.1983-1993
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• 2017

Salmonella enterica subsp. enterica serovar Typhimurium, one of the most common foodborne pathogens, is transmitted mainly through contaminated food derived from infected animals. In this study, S. Typhimurium ST1120, an isolate from pig feces in Korea, was subjected to whole-genome analysis to understand its genomic features associated with virulence. The genome of ST1120 was found to have a circular chromosome of 4,855,001 bp (GC content 52.2%) and a plasmid of 6,863 bp (GC content 46.0%). This chromosome was predicted to have 4,558 open reading frames (ORFs), 17 pseudogenes, 22 rRNA genes, and 86 tRNA genes. Its plasmid was predicted to have three ORFs. Comparative genome analysis revealed that ST1120 was phylogenetically close to S. Typhimurium U288, a critical isolate in piggery farms and food chains in Europe. In silico functional analysis predicted that the ST1120 genome harbored multiple genes associated with virulence and stress resistance, including Salmonella pathogenicity islands (SPIs containing SPI-1 to SPI-5, SPI-13, and SPI-14), C63PI locus, ST104 prophage locus, and various antibiotic resistance genes. In accordance with these analysis results, ST1120 showed competence in invasion and survival abilities when it was added to host cells. It also exhibited robust resistance against antibiotics in comparison with other S. Typhimurium strains. This is the first report of the complete genome sequence of S. Typhimurium isolated from swine in Korea. Comparative genome analysis between ST1120 and other Salmonella strains would provide fruitful information toward understanding Salmonella host specificity and developing control measures against S. Typhimurium infection.

• Korean Journal of Veterinary Service
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• v.39 no.2
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• pp.131-136
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• 2016

Clostridium novyi (C. novyi) is a gram positive, non-capsulated, motile, obligatory anaerobe that produces endospores. Both C. novyi type A and B produce a bacteriophage encoded lethal alpha toxin which belongs to a family of large clostridial cytotoxins. These large clostridial cytotoxins of C. novyi bind to the uncharacterized receptors on host vascular endothelial cells, which leads to the loss of integrity of the vascular endothelium with subsequent edema, refractory hypotension, organ failure, and sudden death. A total of 13 sudden death cases were submitted to Chonbuk National University-Veterinary Diagnostic Center between June and October, 2015. The samples, mainly liver, were collected in sterile vials after necropsy and processed within 12~24 hours for diagnosis, isolation and identification of C. novyi. All of the 4 gram positive samples showed amplification by PCR. Out of 4 positive samples, 3 were detected to be C. novyi type B and 1 was detected as C. novyi type A. Based on the 16S rDNA sequence analysis, 1 case (150564) showed 99% similarity with C. novyi type A while other 3 cases (150388, 150557 and 150775) presented 99% similarity with C. novyi type B. Based on the results, C. novyi was found to be prevalent in Korean pig farms and causes sudden death to finishing pigs or sows during summer season. Thus, C. novyi should be considered for differential diagnosis on sudden death cases during the summer season.

• Korean Journal of Veterinary Service
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• v.39 no.2
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• pp.87-92
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• 2016

Porcine edema disease (ED) is a communicable disease of pigs caused by infection with Shiga toxin (Stx)-producing Escherichia coli (STEC) which expresses F18 fimbriae and/or Stx type 2e (Stx2e). While STEC causes a severe illness including hemorrhagic colitis and hemolytic-uremic syndrome in humans, it induces damage to the vascular endothelium, which results in edema, hemorrhage, and microthrombosis, leading in high mortality in pigs. In the present study, we cultured Stx2e-producing E. coli field isolates from conventional pig farms that experienced sudden deaths previously with symptoms similar to porcine edema disease, which were further investigated with Shiga toxin profiles. A total of 43 strains were identified from the collected samples by F18 or Stx2e specific PCR. Based on the PCR, 42 isolates out of 43 isolates were proved to carry one of F18 or Stx2e genes and 14 isolates to carry both F18 and Stx2e genes. All of the 30 isolates that harbored Stx2e gene induced the cytopathic effect (CPE) in vero cells and especially, the isolate 150229 produced the highest level of Shiga toxin. Therefore, we identified the virulence genes (F18 and Stx2e) and demonstrated Shiga toxin-producing abilities from porcine edema disease causing E. coli filed isolates. These results suggested that one of the isolates could be a vaccine antigen candidate against STEC through further investigating to elicit an immune response.

• Korean Journal of Veterinary Research
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• v.40 no.4
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• pp.707-717
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• 2000

Atropic rhinitis (AR) is one of major respiratory diseases in pigs. AR causes a great economic losses and is considered to be a multifactorial disease in which herd management, heredity, and environment. Several vaccines against have been developed commercially and used in pig farms but the efficacy of each vaccine is still questionable. In this study, one of commercial AR vaccines, which contains inactivated Bordetella bronchiseptica, Pasteurella multocida type D and their toxoid was evaluated for vaccine efficacy by challenge test. Twenty piglets were divided into four groups as follows; group I was piglets from vaccinated sows (twice before parturition); group II was piglets from vaccinated sows (same as group I) and were vaccinated at 1 day old; group III and IV were piglets without any vaccination. Groups I, II, and III were challenged by intranasal instillation of $5.3{\times}10^7$ CFU of B bronchiseptica twice and $1{\times}10^9$ CFU of P multocida five times. Group IV was control group without any vaccination and any challenge. We compared serological results, recovery rate of P multocida by polymerase chain reaction, clinical signs and pathological findings between vaccinated groups and unvaccinated groups for efficacy of the vaccine, Serological responses against B bronchiseptica and toxigenic P multocida type D were not showed evident discrepancy between vaccinated groups and unvaccinated groups assuming that the antibody responses against the vaccine is very delayed. However, growth rate, clinical signs and snout lesion grading in vaccinated groups showed more favorable than those in unvaccinated group. Therefore, AR vaccination in this study is considered to be effective in the prevention of AR in pigs.

• Korean Journal of Veterinary Service
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• v.34 no.2
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• pp.133-138
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• 2011

The prevention of porcine respiratory disease complex (PRDC) is very important because of its high infection-rates in the swine farms and the economic impact in swne industry in Korea. To control the prevalence of PRDC, it is important to know about infection patterns of it. Therefore, this study aimed to investigate the infection patterns of PRDC in the northern area of Gyeongsangnam-do. To this end, the infection of porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), Actinobacillus pleuropneumoniae (APP), Mycoplasma hyopneumoniae (MH), and Swine influenza virus (SIV) were examined using 120 pig lung tissues by PCR analysis. As a result, single pathogen positive specimens were 25.0% and the others (75.0%) were turned out to be PRDC with at least two pathogens. Among PRDCs, 50 specimens (41.7%) was infected with PRRSV, PCV2, MH and SIV. Ten specimens (8.3%) showed triple infections of PRRSV, PCV2 and MH. Double infected specimens for PRRSV and PCV2 were 10 (8.3%), and for PCV2 and APP were 20 (16.7%).

• Korean Journal of Veterinary Service
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• v.34 no.2
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• pp.117-123
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• 2011

This experiment was conducted to investigate the presence of recognized abortifacient viruses from aborted fetuses and stillborn piglets in cases of reproductive failure in sows by PCR. A total of 219 samples of aborted fetuses or stillborn piglets, submitted to the School of Veterinary Medicine of Kangwon National University between 2006 and 2009 May, were collected from 5 provinces in Korea. Abortifacient virus infections were detected in 82 (37.4%) out of 219 aborted fetuses or stillborn piglets as well as on 39 (40.2%) out of 97 pig farms. The major viral infections were porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV) and Aujesky's disease virus (ADV) for which 46 (21%), 19 (8.6%) and 16 (7.3%) were positive, respectively, with 9 fetuses had complicated infection of PCV2+PRRSV or ADV or both. And 8 (3.6%) for SIV, 3 (1.3%) for PPV and 1 (0.4%) for JEV were positive as minor viral infection. The results suggest that PCV2, PRRSV, ADV is apparently the most important viral infectious agents associated with fetal infection leading to abortion or stillbirth in Korea. SIV, PPV and JEV might have a minor impact on reproductive disease.