• Journal of Apiculture
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• v.34 no.2
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• pp.125-129
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• 2019

Honey bees are important pollinators in agriculture, but are threatened by the pathogen Ascosphaera apis, which causes chalkbrood. Despite attempts to control this fungus using synthetic fungicides, none of them have been proven to be completely effective. Among 640 natural compounds that we tested, 4-hydroxyderricin (MIC=3.125, 6.25 mg/L after 24 h and 48 h growth, respectively) exhibited the strongest anti- Ascosphaera apis activity, followed by acetylshikonin (MIC=12.5 mg/L for 24 h and 48 h growth). 4-Hydroxyderricin showed selective growth inhibition of Ascosphaera apis and Rhizopus oryzae among tested fungus strains. Treatment 4-hydroxyderricin with miconazole revealed a synergistic effect (FICI=0.65±0.13 at 48 h incubation). These findings suggest that 4-hydroxyderricin, which has antifungal activity against Ascosphaera apis but few other fungal species, can effectively control infectious fungal diseases. Combined treatment of bees with 4-hydroxyderricin and miconazole could reduce cytotoxicity and improve the cost effectiveness of treatment.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.209.3-209
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• 2005

• Journal of Apiculture
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• v.32 no.1
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• pp.27-39
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• 2017

PCR-chip-based ultra-rapid multiplex PCRs for detection of six major infectious pathogens in honeybee were developed. The 6 kinds of major infectious pathogens in honeybee included Paenibacillus larvae causing American Foulbrood, Melissococcus plutonius causing European Foulbrood as bacteria, Ascosphaera apis (Chalkbrood), Aspergillus flavus (Stonebrood), Nosema apis and Nosema ceranae (Nosemosis) as fungi. The developed PCR-chip-based ultra-rapid multiplex PCR showed successful amplification for all six major pathogens in the presence of more than $10^3$ molecules. The time for confirming amplification (Threshold cycles; Ct-time) was about 7 minutes for two species, and about 9 minutes for four species. Total 40 cycles of PCR took 11 minutes 42 seconds and time for melting point analysis was 1 minute 15 seconds. Total time for whole PCR detection was estimated 12 minutes 57 seconds (40 cycles of PCR and melting point analysis). PCR-chip based ultra-rapid multiplex PCR using standard DNA substrates showed close to 100% accuracy and no false-amplification was found with honeybee genomic DNA. Ultra-rapid multiplex PCR is expected to be a fast and efficient pathogen detection method not only in the laboratory but also in the apiary field.