• 대한수의학회지
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• 제39권1호
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• pp.90-95
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• 1999

A species-specific 760 base pair(bp) BamHI to EcoRI DNA fragment(fMG-2) of lipoprotein gene was isolated from a Mycoplasma gallisepticum(M gallisepticum) genomic library. Based on the DNA sequence data of fMG-2, a pair of 25bp primers was synthesized. When used in the polymerase chain reaction(PCR), 732bp DNA products were amplified from 6 standard strains and 10 field isolates of M gallisepticum, but not from 2 Mycoplasma synoviae and 7 other Mycoplasma species. The lower detection limit was 100fg of the genomic DNA. Identity of the PCR products was confirmed by comparison of patterns of restriction endonuclease analysis with AseI, DraI, EcoRV and SspI.

• 대한수의학회지
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• 제13권1호
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• pp.35-38
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• 1973

It was discovered that furamizole, one of the nitrofuran derivatives, possesses a strong antibacterial activity upon various organisms. Since then, a number of nitrofuran derivatives have been examined for antibacterial activity. This experiment was carried in vitro to evaluate with regard to antibacterial activity upon Mycoplasma gallisepticum. As a result, furamizole was found to be a good effective compound upon Mycoplasma gallisepticum. Furamizole inhibited the growths of the three strains of Mycoplasma gallisepticum and two strains of the same species at a concentration of $0.064{\mu}g/mI$. and $0.016{\mu}g/mI$. In short, there were not great differences in sensitivity to furamizole among the five strains tested.

• Asian-Australasian Journal of Animal Sciences
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• 제6권2호
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• pp.249-251
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• 1993

A total of 4,800 chicken sera from Broiler, Layer, and Local chicken were tested to detect the presence of Mycoplasma gallisepticum (Mg) antibody by Rapid Serum Plate and Tube Agglutination Test. Positive cases recorded in this study were 945 (27%) in Broiler, and 436 (36.7%) in layer chicken sera and no. M. gallisepticum antibody could be seen in the local chicken sera. It is evident from the present findings that Mycoplasma gallisepticum infection has been prevailing in this country in improve breeds of chickens.

• 한국동물위생학회지
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• 제39권2호
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• pp.101-105
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• 2016

The present study investigated serological and molecular prevalence of Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) infection in unvaccinated broiler breeder farms in Jeonbuk providence. An enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) had been used to determine antibody titers against MG and MS, and genome of these pathogens, respectively. Seventy five percent of farms were seropositive for MG and 94% of farms were seropositive for MS. In addition, the rate of antibody positive flocks against MG were 65.3% (32/49), while the rate of positive flocks against MS were 84.2% (80/95). The geometric mean antibody titers were $802.2{\pm}626$ and $27,726.7{\pm}2426$ against MG and MS, respectively. Interestingly, none of samples was positive for MG genome by PCR, while 94% (farms), 82% (flocks) and 62.6% (broiler breeder) were positive for MS genome by PCR. These findings suggest that the prevalence of MG or MS infection could be higher than expected. Thus, strict prevention program including vaccination and environmental sanitation should be implemented to avoid disease transmission from breeder to broilers as well as transmission among broilers.

• 한국동물위생학회지
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• 제33권1호
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• pp.45-50
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• 2010

Mycoplasma gallisepticum (MG) is major cause of chronic respiratory disease in chickens. M. synoviae (MS) most frequently occurs a subclinical upper respiratory infection but may result in airsacculitis and synovitis in chickens and turkeys. Both mycoplasmas induce economic losses by triggering chronic respiratory signs, airsacculitis and decreased egg production. For prevention of the infections, live attenuated andinactivated vaccines are commercially used for prevention of MG but not MS in Korea. Serum plate agglutination (SPA) and enzyme-linked immunosorbent assay (ELISA) have been commonly used for serological diagnosis for MG and MS. Recently, it is believed that MS spread in chickens is very seriously in Korea and respiratory infection with MS causes substantial loss in poultry farms. In this study, we investigated the serological prevalence of MG and MS in unvaccinated chickens between 2008 and 2009. The overall seroprevalence of MG was 24% of 2,094 for individual chickens and 24% of 189 farms. The overall seroprevalence of MS was 36% in 2,095 chickens and 39% in 198 farms. The results show that seropositive ratio of MS is higher than MG. The geographical prevalence of MG has been estimated in following sequence; Gangwon, Jeolla, Gyeonggi, Gyeongsang, and Chungcheong. The geographical prevalence of MS has been estimated as follows; Gangwon, Gyeonggi, Gyeongsang, Chungcheong, and Jeolla. Seasonal seroprevalencewas also examined, and it found that seroprevalence in spring, fall and winter was higher than that in summer in MG, but not in MS. No significant difference was shown in seroprevalence according to breed. Future study about pathogenicity of MS isolates would be needed and economical losses by MS outbreaks should be analyzed. Moreover, we compared sero-positivity obtained with SPA and ELISA. The kappa value of MG between SPA and ELISA was 0.8061 and the kappa value of MS between SPA and ELISA was 0.7649.

• 대한수의학회지
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• 제46권3호
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• pp.207-214
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• 2006

Mycoplasma gallisepticum (MG) continues to persist in many commercial layer farms in Korea,resulting in losses in egg production. Bacterins and live attenuated vaccines have been used for the prevention of losses caused by MG. One of these attenuated vaccines, MG 6/85 vaccine has been reported to be safe and efficacious in layers. However, MG 6/85 vaccine has not been evaluated for its safety and its efficacy in any commercial layer in Korea. Six-week-old specific pathogen-free (SPF) chickens were vaccinated with MG 6/85 vaccine by aerosol and were challenged with virulent MG R strain at 4 weeks after vaccination. The vaccinated group was able to resist challenge into the air sacs because the vaccinated group showed much less air sac lesion compared with the unvaccinated group. Each of two commercial layer farms was divided into vaccinated and unvaccinated groups. For each vaccinated gorup, MG 6/85 vaccine were sprayed at 17 week old on farm A and at 15 weeks old on farm B. Hen-day egg production, Hen-housed eggs, egg weight, mortality were evaluated until 50 week after vaccination.Compared with the unvaccinated group in each farm, the vaccinated group showed higher average egg production and egg weight, and higher hen-housed number. Results of this study are in agreement with other previous reports which demonstrated that MG 6/85 vaccine favorable effect on performance in commercial layers.

• 한국가금학회지
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• 제46권4호
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• pp.249-253
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• 2019

닭 마이코플라즈마병은 전세계적으로 양계산업에 문제시 되고 있는 난계대 질병으로 병아리 품질 및 사육성적에 영향을 미친다고 알려져 있다. 본 연구는 닭 마이코플라즈마병에 대한 백신 접종을 실시하지 않은 계열화 회사의 육용 종계군을 대상으로 정기 채혈을 통해 혈청검사를 실시한 후 감염율을 확인하였고, 조사계군에서 생산된 육계 병아리에 대한 사육성적을 확인하고자 하였다. 육용종계 닭 마이코플라즈마 감염율과 그에 따른 후대병아리의 사육성적을 연도별로 확인한 결과, 종계군의 감염율이 낮아짐에 육계의 사육성적이 높아진다는 상관관계를 확인하였다. 이러한 결과를 토대로 비추어 보았을 때, 닭 마이코플라즈마병의 감염 유무는 생산된 초생추의 품질과 사육농장 성적 영향에 미치는 여러 요소들 중 하나라고 판단할 수 있다.

• 한국동물위생학회지
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• 제43권3호
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• pp.139-145
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• 2020

This study was carried out to identify the occurrence of transovarian transmitted diseases and antibody positive rates among Korean native breeder chickens. The infection rates with Salmonella pullorum and Salmonella gallinarum among 16-week-old, 36-week-old, and 56-week-old breeder chickens and the antibody positive rates to Egg Drop Syndrome '76, Mycoplasma gallisepticum and Mycoplasma synoviae among 16-week-old, 18-week-old, and 56-week-old breeder chickens were identified, and the antibody positive rates to seven major transovarian transmitted diseases among 1-day-old chicks were investigated. As a result, no infection with Salmonella pullorum and Salmonella gallinarum was found among the investigated subjects of all ages. Vaccinated breeder chickens showed the 100% antibody positive rate to Egg Drop Syndrome '76, and unvaccinated breeder chickens showed the 100% antibody negative rate to Mycoplasma gallisepticum and Mycoplasma synoviae, confirming that there was no infection with Mycoplasma gallisepticum and Mycoplasma synoviae. As a result of the antibody tests of the 1-day-old chicks for transovarian transmitted diseases, it was found that vaccinated chicks showed good antibody positive rates to avian encephalomyelitis, chicken infectious anemia, and avian reovirus, confirming that they had power of defense against the relevant infectious diseases, and that unvaccinated chicks showed the 100% antibody negative rates to avian leukosis, chicken reticuloendotheliosis, and Mycoplasma synoviae, confirming that there was no infection with the relevant diseases. Given that the results of this study showed that among the transovarian transmitted diseases of chickens, there was no history of infection with diseases against which vaccination was not administered and high antibody positive rates were found with diseases against which vaccination was administered, it is judged that chickens with good power of defense against diseases were bred, and it is deemed that constant monitoring and vaccination against transovarian transmitted diseases will be necessary for the control and prevention of the diseases.

• 한국동물위생학회지
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• 제40권2호
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• pp.89-94
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• 2017

This study was conducted from May to December 2016 to investigate the prevalence of antibody titers for Newcastle disease (ND), Infectious Bronchitis (IB), Egg drop syndrome (EDS), Avian pneumovirus (APV), Fowl Typhoid (FT), Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS) in laying hens in Incheon area. In ND, 418 (99.5%) of the 420 outbreaks were positive. IB showed 330 (78.5%) positive antibody out of 420 cases. EDS showed 419 (99.7%) positive seropositive rates among 420 cases. In the case of APV, 357 cases (85%) were positive in 420 cases. In the case of PT, the positive rate of antibody was 128 (30.4%) out of 420 cases. Among the 420 cases of MG, 222 cases (52.8%) were positive for antibodies. In the case of MS, 395 out of 420 cases (94.0%) were positive. This result suggests that the positive rate of antibody for PT in Incheon area was low. And it was also clear that MS without vaccine is now rampant in Incheon.

• 한국가금학회지
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• 제37권2호
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• pp.181-190
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• 2010

본 연구에서는 Mycoplasma gallisepticum F 주 생독 백신(PoulShot$^{(R)}$ MG-F)의 안전성과 효능을 평가하였다. 충청북도 진천과 경기도 안성 지역의 산란계 농장을 선정하여, 백신과 야외주 공격 접종에 따른 혈청 역가 변화, 상부 호흡기에서의 마이코플라즈마균 재분리, 조직학적 병변과 백신 접종군 및 백신 미접종군 간의 산란율 및 오파란율의 차이를 농장별로 평가하였다. 백신 접종에 의한 혈청 역가 변화는 백신 접종 후 3주부터 확인되었으며, 농장에 따라 접종 후 23주에서 31주까지 지속됨으로써 백신 항체가 오랫동안 유지되는 것을 확인할 수 있었다. 또한 상부 호흡기에서 MG-F 재분리 및 PCR에 의한 유전자 검출도 백신 접종 후 31주까지 양성이었다. 이러한 항체 및 항원의 지속적인 검출은 상부 호흡기에 MG-F 백신주의 집락 형성이 오랫동안 지속된다는 것을 의미하는 것이다. 동일한 방법으로 백신 접종군에 대한 야외주 공격 접종 후 상부 호흡기에서의 백신주 집락 형성을 분석한 결과, 공격 접종 후 3주까지 백신주의 집락 형성율이 야외주보다 동등하거나 높은 것으로 확인됨으로써 야외주 공격에 대한 백신주의 방어력이 입증되었다. MG-F의 안전성과 생산성 측면에서의 효능을 야외 농장에서 검증하기 위하여 두 실험 농장에서 백신 접종군과 백신 미접종군간의 산란율 및 오파란율을 비교하였다. 그 결과, MG-F 접종에 따른 임상적 부작용과 산란율 하락은 발견되지 않았으며, 오히려 백신 접종군의 오파란율이 백신 미접종군보다 평균 1~3% 낮은 것으로 분석됨으로써 백신 접종에 의한 난질 개선 효과가 있음이 확인되었다. 따라서, PoulShot$^{(R)}$ MG-F 생균백신을 산란계에 접종하였을 때 임상적으로 안전하였으며, 오랜 기간 야외 감염에 방어할 수 있는 항체 형성과 상부 호흡기에서의 지속성이 확인됨으로써 마이코플라즈마 야외 감염을 효율적으로 방어할 수 있을 것으로 판단된다.