• 대한수의학회지
• /
• 제50권2호
• /
• pp.117-124
• /
• 2010

Members of the genus Brucella are facultative intracellular bacteria and cause brucellosis, a chronic disease in humans and abortion in animals. In this study, we tested sera for brucellosis of 15 Hanwoo farms in the western part of Gyeong-buk province, resulting 5 farms were brucellosis positive in 2008. We collected blood from 277 heads in the brucellosis positive 5 farms, and performed serological diagnosis, brucella positive cattle which had shown higher than 200 antibody titer in tube agglutination test were slaughtered, supramammary lymph nodes were collected, and Brucella spp. wild type isolation and identification were performed. From these results, 15 of Brucella spp. wild type strains were isolated and all strains were identified as B. abortus biotype 1 by biological and molecular analysis. In the antimicrobial susceptibility test, all 15 strains had a similar susceptibility and resistance pattern. This study may be useful for bacteriological and epidemiological understanding of cattle brucellosis in Korea.

• The Plant Pathology Journal
• /
• 제28권2호
• /
• pp.123-136
• /
• 2012

Diseases caused by begomoviruses (family Geminiviridae, genus Begomovirus) constitute a serious constraint to tropical and sub-tropical agro-ecosystems worldwide. In recent years, they have also introduced in temperate regions of the world where they have great impact and are posing a serious threat to a variety of greenhouse crops. Begomoviral diseases can in extreme cases reduce yields to zero leading to catastrophic losses in agriculture. They are still evolving and pose a serious threat to sustainable agriculture across the world, particularly in tropics and sub-tropics. Till recently, there have been no records on the occurrence of begomoviral disease in South Korea, however, the etiology of other plant viral diseases are known since last century. The first begomovirus infected sample was collected from sweet potato plant in 2003 and since then there has been gradual increase in the begomoviral epidemics specially in tomato and sweet potato crops. So far, 48 begomovirus sequences originating from various plant species have been submitted in public sequence data base from different parts of the country. The rapid emergence of begomoviral epidemics might be with some of the factors like evolution of new variants of the viruses, appearance of efficient vectors, changing cropping systems, introduction of susceptible plant varieties, increase in global trade in agricultural products, intercontinental transportation networks, and changes in global climatic conditions. Another concern might be the emergence of a begomovirus complex and satellite DNA molecules. Thorough understanding of the pathosystems is needed for the designing of effective managements. Efforts should also be made towards the integration of the resistant genes for the development of transgenic plants specially tomato and sweet potato as they have been found to be widely infected in South Korea. There should be efficient surveillance for emergence or incursions of other begomoviruses and biotypes of whitefly. This review discusses the general characteristics of begomoviruses, transmission by their vector B. tabaci with an especial emphasis on the occurrence and distribution of begomoviruses in South Korea, and control measures that must be addressed in order to develop more sustainable management strategies.

• Restorative Dentistry and Endodontics
• /
• 제8권1호
• /
• pp.31-44
• /
• 1982

Streptococcus mutans strains were isolated from dental plaques of carious lesions of 53 patients on mitis-salivarius-bacitracin (MSB) and mitis-salivarius(MS) medium as a supplement. The epidemiological investigation was carried out to determine the biotypes and serotypes of S. mutans isolates. For the serotyping, autoclaved extract antigens from the isolates and serotype-specific antisera against seven known serotypes of S. mutans were prepared. The serotypes of the isolates were demonstrated in immunodiffusion test. In addtition, the prevalence of ${\beta}$-hemolysis on 5% sheep blood agar plate in restricted anaerobic condition and yellow pigment production on 5% sucrose agar plate in less anaerobic condition among the isolates were investigated. The results were as follows: 1. Forty-eight S. mutans strains were isolated from dental plaque samples of 33 patients (62.3%) among 53 patients. 2. Of the isolates, some strains were not grown on MSB medium. 3. Serotype c S. mutans was found in 60.6%, serotype d was found in 30.3% of the patients who were known to harbor S. mutans. 4. Of. the isolates, serotype c isolates were most prevalent (43.8%), serotype d isolates were 25.0%, and serotype b, e, f and g isolates were also found but in lower frequencies. Serotype a S. mutans were not detected. 5. The correlation between serotype and biotype of the isolates was found in 78.6% of the typing cases. 6. Strains revealed ${\beta}$-hemolysis were in 52.1% of the isolates, strains produced yellow pigment were in 47.9% of the isolates, and with one exception, all the strains were belong to serotype c, e and f. 7. The majority of the isolates which revealed ${\beta}$-hemolysis appeared to be yellow pigmented, these isolates were belong to serotype c, e and f.

• 식물병연구
• /
• 제28권1호
• /
• pp.39-45
• /
• 2022

경기 광주시 완숙토마토 시설재배단지에서 가루이가 매개하는 바이러스 2종 tomato yellow leaf curl virus (TYLCV)와 tomato chlorosis virus (ToCV)의 발생양상을 조사하였다. 2020년 여름재배 작형에서 TYLCV와 ToCV의 감염률은 수확기에 급격히 증가하였고, 단독 감염률은 각각 30.9%, 5.0%였고, 복합감염률은 52.2%로 TYLCV 단독감염과 2종 바이러스 복합감염이 83.1%로 대부분을 차지하였다. 2종 바이러스를 매개하는 가루이의 발생분포 및 보독률을 조사한 결과, 작물 재배기간 내내 담배가루이가 높은 비율로 발생하였고, 조사한 담배가루이는 모두 Mediterranean (MED)으로 확인되었다. 담배가루이 MED는 TYLCV를 단독으로 보독하거나 ToCV와 복합 보독하는 경우가 48.5%로 많았으며, ToCV의 보독률은 29.1%로 온실가루이(7.2%)에 비해 높았다. 담배가루이 MED의 2종 바이러스 보독률이 토마토 정식 전부터 47.2%로 높았고, 이후 계속 증가하여 수확기에는 73.8%로 가장 높았다. 수확기 토마토 재배포장별 2종 바이러스의 감염률에 따라 수확량을 비교 분석해본 결과, TYLCV와 ToCV의 복합감염률 증가가 수확량을 감소시키는 것을 확인하였고, 복합감염률이 10% 증가함에 따라 405.4 kg/10a 수량감소를 보였다.