• Korean Journal of Veterinary Service
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• v.45 no.1
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• pp.63-69
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• 2022

Proliferative and necrotizing pneumonia (PNP) is a form of interstitial pneumonia that occurs in post-weaning pigs. In this study, we investigated the presence of swine influenza virus (SIV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2) and Aujeszky's disease virus (ADV) in PNP lesions in Jeju pigs. Based on the histopathologic criteria for PNP, a total of 50 cases were selected in Jeju pigs between 2008 and 2010. Coupled with histopathological examinations, the presence of ADV and SIV by polymerase chain reaction (PCR) and reverse transcription PCR (RT-PCR) and PRRSV and PCV2 by immunohistochemical (IHC) methods were investigated. Based on the PCR and RT-PCR methods, ADV and SIV nucleic acids were not detected in all cases. According to IHC, PRRSV was detected in 38 of the 50 cases examined (76%) and PCV2 in 25 cases (50%). PRRSV or PCV2 were detected in 19 (38%) or 6 (12%) cases, respectively. Both PRRSV and PCV2 were identified in other 19 cases (38%). Antigens of PRRSV and PCV2 were commonly observed in the cytoplasm of macrophages and clusters of necrotic cells in alveolar cavities. The results of the present study demonstrate that PRRSV is predominantly associated with PNP in Jeju pigs. Co-infection with PRRSV and PCV2 may enhance the severity of PNP lesions in affected pigs.

• Korean Journal of Veterinary Service
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• v.18 no.2
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• pp.124-132
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• 1995

The present study was conducted to investigate the incidence of Pasteurella multocida infection in cheju swine from March 1994 to December 1994 isolated organisms were identified by the biochemical properties, cellulose serological type and antibiotic susceptibilities. Pasteurella multocida was isolated from the Lungs of 96 pigs with pneumonia(51 %) among 188 slaughtered pigs. The majority of p multocida isolates were identical to those of the standard strains. On the classification of the capsular type of the isolated p multocida it consist of the 88 isolates of type A(91.6%) 2 isolates of type D (2%) and un classified 6 types(6.2%). The majority of the 96 isolates of p multocida highly susceptible to the antibiotics including ampicillin(Am), cephalotin(Ce), erythromycin(Em), gentamycin(Gm), kanamycin(Km), lincomycin(Lm), neomycin(Nm), penicillin(Pc), streptomycin(Sm), solfametoxazol/trimethoprim(Sxt) and tetracycline(Te)

• Korean Journal of Veterinary Service
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• v.22 no.1
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• pp.9-13
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• 1999

Mycoplasmal pneumonia of swine(MPS) cause by Mycoplasma hyopneumoniae has been recognized as a serious impediment to swine production due to chronic respiratory disorder which result in the weight loss and decreased feed conversion. The disease causes a great economic losses in pig industry by characterizing with high morbidity, low mortality, growth retardation and low feed efficiency. The present study was conducted to investigate the titers of antibody against M hyopneumoniae from the regional and seasonal groups of the slaughtered pigs by enzyme-linked immunosorbent assay(ELISA). The result have shown that the average seropositive rate of M hyopneumoniae infection was 84.6% . The regional seropositive rate in Korea showed 87.4% in Kyonggj, 83.4n in Kangwon, 89.2% in Chungnam and 77.6% in Chungbuk area, respectively. Also the seasonal seropositive rate was appeared as 78.6% in spring,90.1% in summer, 76.9% in autumn and 83.8% in winter, respectively.

• Korean Journal of Veterinary Service
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• v.25 no.3
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• pp.237-243
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• 2002

The study was performed to investigate the antibody distributions of 4 swine respiratory disease including M hyopneumoniae, P multocida, A pleuropneumoniae serotype 2 and 5 in Daegu area by enzyme-linked immunosorbent assay(ELISA). 1. The overall sero-positive rates were 55.6% in June, 48.0% in August, 51.3% in October and 25.4% in November. 2. The positive reaction rates to M hyopneumoniae, P multocida, A pleuropneumoniae serotype 2 and 5 were found to be 50.0%, 36.5%, 55.0%, and 42.0% respectively. 3. The antibody titers were distributed on range 20～80 in M hyopneumoniae, 20～80 in P multocida, 160～640, 20～80 in A pleuropneumoniae serotype 2 and 5.

• Journal of Life Science
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• v.30 no.9
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• pp.749-762
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• 2020

Influenza A viruses are circulating in a variety of hosts, including humans, pigs, and poultry. Swine influenza virus is a zoonotic pathogen that can be readily transmitted to humans. The influenza viruses of the 2009 H1N1 pandemic were derived from swine influenza viruses, and it has been suggested that the 1957 H2N2 pandemic and the 1968 H3N2 pandemic both originated in pigs. Pigs are regarded as a mixing vessel in the creation of novel influenza viruses since they are readily infected with human and avian influenza viruses. We isolated three novel H1N2 influenza viruses from pigs showing respiratory symptoms on a Korean farm in 2019. These viruses were reassortants, containing PA and NP genes from those of the 2009 H1N1 influenza virus in addition to PB2, PB1, HA, NA, M, and NS genes from those of triple-reassortant swine H3N2 and classical swine H1N2 influenza viruses circulating in Korean pigs. Mice infected with the isolated H1N2 influenza virus lost up to 17% body weight and exhibited interstitial pneumonia involving infiltration of many inflammatory cells. Results suggest that close surveillance to detect emerging influenza viruses in pigs is necessary for the health of both pigs and humans.

• Korean Journal of Veterinary Research
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• v.52 no.1
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• pp.39-43
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• 2012

A multiplex PCR was developed for the simultaneous detection and differentiation of Mycoplasma (M.) hyopneumoniae and M. hyorhinis in clinical samples. Improved sensitivity is advantage of this technique over the previously reported multiplex assay. It was capable of detecting as little as 125 fg genomic DNA from M. hyopneumoniae and 62.5 fg genomic DNA from M. hyorhinis. Application of this multiplex PCR method to field isolates showed that M. hyopneumoniae and M. hyorhinis were present in 29% (107 of 370) of lung specimens and no mycoplasmas were detected in 56% (208 of 370) of the slaughtered pigs' lungs. At the farm level, M. hyopneumoniae and M. hyorhinis were detected in 34 of 36 (94.4%) randomly selected farms. We conclude that this assay would prove itself a value tool for monitoring these mycoplasmal infections and both M. hyopneumoniae and M. hyorhinis have been widely spread in swine herds of Korea.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1756-1763
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• 2010

Pasteurella multocida serogroup D strain, which produces P. multocida toxin (PMT), is a widespread and harmful pathogen of respiratory diseases such as pneumonia and progressive atrophic rhinitis (PAR) in swine. Vaccination has been considered the most desirable and effective approach for controlling the diseases caused by toxigenic P. multocida. To investigate the antigenicity and immunogenicity of partial fragments of recombinant PMT, recombinant proteins of the N-terminal (PMT-A), middle (PMT-B), C-terminal (PMT-C), and middle-C-terminal (PMT2.3) regions of PMT were successfully produced in an Escherichia coli expression system. The molecular masses of PMT-A, PMT-B, PMT-C, and PMT2.3 were ca. 53, 55, 35, and 84 kDa, respectively, purified by nickel-nitrilotriacetic acid (Ni-NTA) affinity column chromatography. All the recombinant proteins except for PMT-A showed immune responses to antisera obtained from a swine showing symptoms of PAR. Moreover, high titers of PMT-specific antibodies were raised from mice immunized with each of the recombinant proteins; however, the immunoreactivities of the antibodies to authentic PMT and heat-inactivated whole bacteria were different, respectively. In the protection study, the highest protection against homologous challenge was shown in the case of PMT2.3; relatively poor protections occurred for the other PMT fragments.

• Korean Journal of Veterinary Service
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• v.13 no.1
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• pp.69-74
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• 1990

The present study was conducted to investigate the incidence of pasteurella multocida infection in kyungbuk swine herds during the period from July 1989 to November 1989 and some properties of the isolated organisms. P. multocida was isolated from lungs of 155 slaughtered pigs, 43(27.7%) pigs were culture positive. The majority of biochemical and cultural properties of the P. multocida isolates were identical to those of the standard strains. The capsular serogroups and drug susceptibility of 43 isolates of P. multocida from pigs with pneumonic lesions were investigated. P. multocida isolates were typed for capsular serogroupes A by hyaluronidase inhibition of capsule and D by acriflavin auto agglutination. Most isolates(60.4%) were type A, 18.6% were type D, and the remaining 21.0% were untypable. In antimicrobial susceptibility test these isolates of P. multocida were susceptible in order of ampicillin (86.0%), trimethoprim sulfamethoxazole(83.7%), colistin(81.4%), chloramphenicol(79.1%), but the majority of them were resistant in order of streptomycin(30.2%), triple sulfa (4.6%).

• Korean Journal of Veterinary Service
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• v.27 no.2
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• pp.121-131
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• 2004

This experiment was executed to control effectively endemic disease of swine farms in Incheon metropolitan city. Mainly using PigMon program which had been developed by the College of Veterinary Medicine in the University of Minnesota(USA), we examined lesions of gastric ulcer and interstitial nephritis additionally. 446 heads of pigs shipped from 5 farms in Incheon to a slaughterhouse from June in 2003 to May in 2004 were examined. Infection rates by farms were obtained as follows; 1. Pneumonia was varied from 34.6% to 74.1% and pneumonic score was 1.47∼7.06. As for atrophic rhinitis, four farms were 100% and one farm was 89.5% and rhinitis score was 1.3∼3.2. 2. The infection rate of pericarditis and peritonitis was 1.0∼3.9% and liver white spots, papular dermatitis were observed in pigs of 9.8∼29.7%, 16.7∼51.4% respectively. 3. The outbreak rates of interstitial nephritis, lesions of ileal thickening and gastric ulcer were 15.4∼24.1%, 7.7∼13.5%, and 62.7%∼86.2% respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.187-196
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• 2020

Objective: Porcine respiratory disease is one of the most important health problems causing significant economic losses. To understand the genetic basis for susceptibility to swine enzootic pneumonia (EP) in pigs, we detected 102,809 single nucleotide polymorphisms in a total of 249 individuals based on genome-wide sequencing data. Methods: Genome comparison of susceptibility to swine EP in three pig breeds (Jinhua, Erhualian, and Meishan) with two western lines that are considered more resistant (Duroc and Landrace) using cross-population extended haplotype homozygosity and F-statistic (F_ST) statistical approaches identified 691 positively selected genes. Based on quantitative trait loci, gene ontology terms and literature search, we selected 14 candidate genes that have convincible biological functions associated with swine EP or human asthma. Results: Most of these genes were tested by several methods including transcription analysis and candidate genes association study. Among these genes: cytochrome P450 1A1 and catenin beta 1 (CTNNB1) are involved in fertility; transforming growth factor beta receptor 3 plays a role in meat quality traits; Wnt family member 2, CTNNB1 and transcription factor 7 take part in adipogenesis and fat deposition simultaneously; plasminogen activator, urokinase receptor (completely linked to AXL receptor tyrosine kinase, r² = 1) plays an essential role in the successful ovulation of matured oocytes in pigs; colipase like 2 (strongly linked to SAM pointed domain containing ETS transcription factor, r² = 0.848) is involved in male fertility. Conclusion: These adverse genes susceptible to swine EP may be selected while selecting for economic traits (especially reproduction traits) due to pleiotropic and hitchhiking effect of linked genes. Our study provided a completely new point of view to understand the genetic basis for susceptibility or resistance to swine EP in pigs thereby, provides insight for designing sustainable breed selection programs. Finally, the candidate genes are crucial due to their potential roles in respiratory diseases in a large number of species, including human.