• 한국양봉학회지
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• 제34권2호
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• pp.137-140
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• 2019

Although honeybees (Apis mellifera) are crucial for maintenance of the ecosystem, population of honeybee has been steadily decreasing due to diseases including nosemosis. Nosemosis is a disease caused by Nosema ceranae and is now considered as a major threat to honeybees. N. ceranae is a microsporidian that stays in form of spore even before the infection, which makes it harder to control than other pathogens. People are now aware of this parasite, however, cure and preventive candidates for nosemosis are hardly found until today. In this study, in vitro experiment of Lespedeza cuneata treatment to prevent nosemosis were done using Trichoplusia ni cell line, BTI-TN5B1-4. Normal T. ni cells exhibited round shape without abnormal size. On the other hand, when N. ceranae were treated, cells deteriorated and some cells abnormally enlarged due to N. ceranae infection. Interestingly, treatment of T. ni cells with L. cuneate extract protected abnormal cell shape induced by N. ceranae infection to normal shape. Some N. ceranae spores were observed outside of the cells. Effective concentration range for N. ceranae control were experimented. Lowest concentration which can control nosemosis were 50 ㎍/mL. When the concentration of L. cuneata extract was exceeded 200 ㎍/mL, cytotoxicity started to show up.

• 미생물학회지
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• 제49권3호
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• pp.270-274
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• 2013

서양뒤영벌(Bombus terrestris)은 꿀벌의 봉군붕괴증후군(colony collapse disorder)에 대한 대체 화분매개곤충으로서 농업분야에서 중요한 역할을 하고 있다. 최근 서양뒤영벌에서 바이러스, 세균, 응애 등의 여러 병원체와 기생체가 발견되었고, 이들은 서양뒤영벌의 수명과 생식력 등에 영향을 주는 것이 알려져 있다. 서양뒤영벌 야외개체군에서 Nosema spp.를 탐지하기 위해, 서양뒤영벌 성충으로부터 genomic DNA를 추출하여 Nosema spp. 유전자들에 대해 polymerase chain reaction (PCR)을 수행하였다. 이들 유전자 중에서 small subunit ribosomal RNA (SSU rRNA) 유전자만이 증폭되었고, 염기서열분석을 통해 N. ceranae로 확인된 것은 조사된 야외개체군에서 N. ceranae가 서양뒤영벌의 주된 감염체임을 보여준다. Quantitative real-time PCR (qRT-PCR)을 이용하여 SSU rRNA 유전자를 탐지하기 위해, 먼저 PCR을 통해 SSU rRNA 유전자의 2개 영역에 대한 유전자 특이적 증폭을 확인하였다. qRT-PCR을 이용하여 각 개체에서 얻은 genomic DNA의 순차적인 농도희석를 통해 $0.85ng/{\mu}l$ 이하의 genomic DNA 농도에서도 SSU rRNA 유전자가 성공적으로 증폭되는 것이 확인되었다. 이러한 실험 결과, qRT-PCR를 이용한 N. ceranae 특이 유전자 증폭은 서양뒤영벌의 병원체 감염 진단 뿐만 아니라 생태계 위해성 평가에도 활용될 수 있을 것으로 사료된다.

• Mycobiology
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• 제45권3호
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• pp.204-208
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• 2017

Nosema ceranae is an obligate intracellular fungal parasite that causes mortality in honey bees and enhances the susceptibility of honey bees to other pathogens. Efficient purification of Nosema spores from the midgut of infected honey bees is very important because Nosema is non-culturable and only seasonably available. To achieve a higher yield of spores from honey bees, in this study, we considered that the initial release of spores from the midgut tissues was the most critical step. The use of 2 mm beads along with enzymatic treatment with collagenase and trypsin enhanced the homogenization of tissues and the yield of released spores by approximately 2.95 times compared with the use of common 3 mm beads alone. The optimal time for the enzyme treatment was determined to be 1 hr as measured by the yield and viability of the spores. A one-step filtration using a filter paper with an $8-11{\mu}m$ pore size was sufficient for removing cell debris. This method may be useful to purify not only N. ceranae spores but also other Nosema spp. spores.

• Journal of Veterinary Science
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• 제22권3호
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• pp.40.1-40.12
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• 2021

Background: The microsporidian parasite Nosema ceranae is a global problem in honeybee populations and is known to cause winter mortality. A sensitive and rapid tool for stable quantitative detection is necessary to establish further research related to the diagnosis, prevention, and treatment of this pathogen. Objectives: The present study aimed to develop a quantitative method that incorporates ultra-rapid real-time quantitative polymerase chain reaction (UR-qPCR) for the rapid enumeration of N. ceranae in infected bees. Methods: A procedure for UR-qPCR detection of N. ceranae was developed, and the advantages of molecular detection were evaluated in comparison with microscopic enumeration. Results: UR-qPCR was more sensitive than microscopic enumeration for detecting two copies of N. ceranae DNA and 24 spores per bee. Meanwhile, the limit of detection by microscopy was 2.40 × 10⁴ spores/bee, and the stable detection level was ≥ 2.40 × 10⁵ spores/bee. The results of N. ceranae calculations from the infected honeybees and purified spores by UR-qPCR showed that the DNA copy number was approximately 8-fold higher than the spore count. Additionally, honeybees infected with N. ceranae with 2.74 × 10⁴ copies of N. ceranae DNA were incapable of detection by microscopy. The results of quantitative analysis using UR-qPCR were accomplished within 20 min. Conclusions: UR-qPCR is expected to be the most rapid molecular method for Nosema detection and has been developed for diagnosing nosemosis at low levels of infection.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
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• pp.6-6
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• 2023

Nosemosis is one of the most common protozoan diseases of adult bees (Apis mellifera). Nosemosis is caused by two species of microsporidia; Nosema apis and Nosema ceranae. Nosema ceranae is potentially more dangerous because it has the ability to infect multiple cell types, and it is now the predominant microsporidian species in A. mellifera. In this study, we identified two anti-nosemosis plants, Aster scaber and Artemisia dubia, which reduced the spore development of N. ceranae in spore-infected cells. We intend to establish the anti-nosemosis activity of aqueous, ethyl acetate (EA), and butanol (BuOH) extracts of A. dubia and A. scaber. In order to determine the optimal dose, we did in vitro and in vivo toxicity for all the extracts and carried out anti-nosemosis experiments. Although all of the extracts (aqueous, EA, and BuOH) showed in vitro and in vivo anti-nosemosis activity in a dose-dependent manner, the aqueous extracts of A. dubia and A. scaber showed more potent anti-nosemosis activity than the EA and BuOH extracts. And then, we isolated five phenolic compounds [chlorogenic acid, 3,4-dicaffaeoylquinic acid (3,4-DCQA), 3,5-dicaffaeoylquinic acid (3,5-DCQA), 4,5-dicaffaeoylquinic acid (4,5-DCQA), and coumarin] from A. dubia, A. scaber, and A. dubia + A. scaber aqueous extracts and screened for their toxicities and anti-Nosema effects in both in vivo and in vitro conditions. Among these five compounds, coumarin, chlorogenic acid, and 4,5-DCQA exhibited less toxic but more potent anti-Nosema effects than the other two compounds. Especially, chlorogenic acid and coumarin showed prominent anti-Nosema activities even at the lowest concentration (10 ㎍/mL). They might have potential to be developed as alternative compounds for the control of Nosema disease.

• 한국양봉학회지
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• 제32권1호
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• pp.27-39
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• 2017

꿀벌 6종 주요 감염성 질병을 동시 진단하기 위한 PCR-chip 기반 초고속 다중 PCR 진단법을 개발 하였다. 6종 주요 꿀벌 감염성 병원체들은, 세균성 질병인 미국부저병의 원인균, Paenibacillus larvae와 유럽부저병의 원인균인 Melissococcus plutonius, 또한 진균인 Ascosphaera apis(백묵병), Aspergillus flavus(석고병)와 Nosema apis, Nosema ceranae(노제마병)를 선발하였다. 개발된 PCR-chip 기반 초고속 다중 PCR은, 꿀벌 주요 병원체 6종에 대하여 각기 $10^3$ 분자이상이 존재할 경우 모두 성공적 증폭을 보였으며, 증폭여부의 확인에 걸린 시간(Ct-time)은 6종 중 4종은 9분 내외, 2종은 7분 내외이었으며, 총 40회전의 PCR은 11분 42초, 융점분석 1분 15초로 총 PCR분석에 소요된 시간은 12분 57초(40회전 및 융점분석)이었다. 표준 DNA 기질을 사용한 PCR-chip 기반 초고속 다중 PCR은 100%에 근접한 정확도를 보였으며, 꿀벌 genomic DNA를 사용한 실험에서 false-amplification은 발견되지 아니하였다. PCR-chip 기반 초고속 다중 PCR은 실험실 내 초고속 진단 뿐 아니라 양봉 현장에서도 신속하고 효율적인 병원체 검출법이 될 것으로 기대한다.