• Korean Journal of Veterinary Service
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• v.37 no.4
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• pp.247-252
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• 2014

The economic impact of swine mycoplasma infection is high. An accurate diagnosis is often difficult and time consuming. We report the development and validation of an effective multiplex polymerase chain reaction (PCR) assay that detects Mycoplasma (M.) hyopneumoniae and M. hyorhinis. The multi detection of M. hyopneumoniae and M. hyorhinis primer set were employed to detect mycoplasma species and typing of the species was performed on the basis of sequence analysis of the PCR product. The target nucleic acid fragments were specifically amplified by M. hyopneumoniae and M. hyorhinis PCR with 16S ribosomal DNA primers. Single and mixed Mycoplasma species DNA templates were used to evaluate the specificity of the multiplex assay. The corresponding specific DNA products were amplified for each pathogen. The multiplex PCR assay provides a novel tool for simultaneous detection and differentiation of M. hyopneumoniae and M. hyorhinis.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.365-370
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• 2005

Enzootic pneumonia caused by Mycoplasma hyopneumoniae is responsible for major economic losses in pig herds of world wide. Mycoplasma hyopneumoniae can also act as a primary pathogen of porcine respiratory disease complex followed by bacterial or viral infection. This study was carried out to investigate the prevalence of mycoplasmal pneumonia of slaughtered pigs in Jeju for two years. The lungs and sera of 214 cases were examined for gross and microscopic lesions of the lungs, immunohistichemistry test for Mycoplasma hyopneumoniae antigen and enzyme-linked immunohistichemistry assay (ELISA) for serum antibody titer. Pulmonary consolidation was observed in the lungs of 163 pigs $(76.1\%)$ with average gross lesion score of $6.0\%$., Bronchointerstitial pneumonia was most frequently observed $(78.5\%)$. The incidence of pulmonary consolidation was decreased in vaccinated pigs compared to that of non-vaccinated pigs. The rate of consolidation in the lungs was significantly decreased in the vaccinated pigs (P<0.05). Antigen of Mycoplasma hyopneumoniae was identified by immunohistichemistry test in the lungs of 174 pigs $(81.3\%)$. ELISh antibodies to Mycoplasma hyopneumoniae were detected in 154 pigs $(72.0\%)$. These results showed the prevalence of swine pneumonia and the incidence of Mycoplasma hyopneumoniae in slaughtered pigs of Jeiu province. We expect that these results would be helpful for the control of swine mycoplasmal pneumonia and porcine respiratory disease complex in Jeju.

• 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 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 Veterinary Clinics
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• v.18 no.2
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• pp.93-97
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• 2001

병원성 Mycoplasma hyopneumoniae strain 91-3, 비병원성 M. hyopneumoniae 그리고 M. flocculare를 돼지의 기관지섬모상피에 투여시 세포내 $Ca^{2+}$ 농도 [$Ca^{2+]}$$_{i}$ 의 변화를 본 연구에서 조사하였다. M. hyopneumoniae strain 91-3 (300-$\mu\textrm{g}$ml)를 투여시 기관지 섬모상피내의 $Ca^{2+}$가 투여전과 비교시 투여 후 250$\pm$19 nM (net increase)증가하였다 (10회 반복 47 cells). 이와는 대조적으로 비병원성 M. hyopneumoniae (300 $\mu\textrm{g}$ml) (6회 반복 18 cells)와 M. flocculare (300 $\mu\textrm{g}$ml) (8회 반복 24 cells)는 세포내 $Ca^{2+}$의 농도를 증가시키지 못하였다. 위의 결과로 병원성 M. hyopneumoniae 91-3 균주는 비병원성 mycoplasma와는 다르게 돼지의 섬모상피에서 [$Ca^{2+}$]$_{i}$ 을 유도하였으며 이러한 특성은 mycoplasma 감염증 치료에 중요한 단서를 제공할 뿐만 아니라 새로운 치료법의 개발에 유용한 스크리닝 기술에 응용될 것으로 기대된다.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1218-1223
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• 1999

The purposes of this study are to examine seroprevalence of Mycoplasma hyopneumoniae infection in pigs of different age groups, and retrospectively determine if nursery depopulation (ND) could influence the seroprevalence of M hyopneumoniae infection in nurseries. Sera of 4, 8, 12, 16, and 20 weeks old pigs from 7 farms were first selected from a serum bank to examine serologic profiles for M hyopneumoniae infections. Availability of representative sera in the serum bank was a major criterion for farm selection. The sera were tested for M hyopneumoniae antibodies by an enzyme linked immunosorbent assay (ELISA) using Tween-20 extracted antigen. Serum samples were also selected from 15 of 34 swine farms that previously participated in a ND study. In order to evaluate M hyopneumoniae infection following ND, ELISA was performed with sera of 8~10 weeks old nursery pigs collected prior to and after ND for up to 12 months from the 15 farms. Serological profiles showed positive ELISA titers for 2 of 7 farms at 8 weeks, 4 of 7 farms at 12 weeks, 6 of 7 farms at 16 weeks, 6 of 6 farms at 20 weeks of age. Prior to ND, 11 of the 15 farms had positive titers in sera of 8~10 weeks old pigs. Sera of 8~10 weeks old pigs collected from 7 of the 11 farms (63.6%) were ELISA antibody negative for up to 12 months following ND. In conclusion, seroconversion to M hyopneumoniae was detected commonly between 10~16 weeks of age, indicating the occurrence of natural infection during the nursery age. The ND appeared to be an effective method to prevent M hyopneumoniae infection within the nursery pig in some farms.

• Toxicological Research
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• v.25 no.3
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• pp.119-124
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• 2009

Genes related to Mycoplasma hyopneumoniae-induced inflammation were identified using the genefishing technology, an improved method for identifying differentially expressed genes (DEGs) using an annealing control primer (ACP) system in RAW264.7 cells. After treatment with M. hyopneumoniae, 16 DEGs were expressed in RAW264.7 cells using a pre-screening system. Among these 16 DEGs, 11 DEGs (DEGs 1, 4, 5-10, 12-15) were selected and sequenced directly, revealing that DEG12 (Grap), DEG14 (Gadd45), and DEG15 (secreted phosphoprotein 1) were related to inflammatory cytokines. This is the first report that intact M. hyopneumoniae induces the expression of Grap, Gadd 45${\beta}$, and secreted phosphoprotein 1 in RAW264.7 cells. Subsequently, these genes may be targets for screening novel inhibitors of the mycoplasmal inflammatory response.

• Korean Journal of Veterinary Research
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• v.56 no.2
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• pp.109-111
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• 2016

The present study was conducted to determine the antibiotic susceptibilities of local Mycoplasma hyopneumoniae (Mhp) and Mycoplasma hyorhinis (Mhr) filed isolates. Minimum inhibitory concentrations (MICs) of Mhp and Mhr field isolates (twelve each) obtained from enzootic pneumonia-like lung lesions during 2009-2011 from Korea were determined using the broth microdilution method. Tylvalosin showed the highest activity against Mhp and Mhr field isolates, with $MIC_{90}$ values of $0.06{\mu}g/mL$ and $0.12{\mu}g/mL$, respectively. Therefore, Korean Mhp and Mhr isolates are highly susceptible to tylvalosin.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.29-29
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• 2003

Mycoplasma hyopneumoniae is among the most prevalent and important infectious agents associated with porcine respiratory disease complex. The airway dagame caused by M. hyopneumoniae adversely affect the pulmonary host defense mechanisms and may lead to secondary bacterial infections. Culture is considered to be the "gold standard" for diagnosis but this is a very slow and labor-intensive procedure. Isolation of M. hyopneumoniae is complicated by its fastidious nature and extremely slow growth. Thirty days of incubation may be necessary to detect the organism in primary broth cultures. The purposes of the study were (ⅰ) to develop nested PCR for the detection of M. hyopneumoniae for the detection of M. hyopneumoniae DNA in the formalin-fixed, paraffin-embedded lung tissues from experimentally and naturally infected pigs and (ⅱ) to compare the utility of nested PCR with in situ hybridization. (omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2005.05a
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• pp.146-146
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• 2005