• Journal of Apiculture
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• v.32 no.2
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• pp.89-97
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• 2017

korean Sacbrood Virus (kSBV) was firstly found since 2008 in Korea, and it might be a main reason why 99% of populations belonged to Apis cerana in Korea were disappeared now. In this study, full length, reported DNA sequences of 32 Sacbrood Viruses (SBVs) were analysed based on alignments using nucleotides and/or deduced amino acid sequeces. In this analysis, variable deletions were found that are located around 2,100 bases in each CDS of SBVs. The genotyping depended on these deletions might be related with infection-patterns by these pathogens. In addition, it is not escaped our notice that the genotyping we have proposed immediately suggests a possible origin of kSBV for the quarantine and protection against further invasion.

• Journal of Apiculture
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• v.32 no.4
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• pp.281-293
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• 2017

Sacbrood virus (SBV) is one of the main pathogenic RNA viruses of honeybee. SBV is found worldwide and many local strains have been reported, such as kSBV, cSBV, and wSBV. In this study, SBV-specific DNA fragments were cloned and sequenced by reverse-transcription PCR from 4 populations of A. mellifera, 4 sequences from 1 population belonged to the 2134D51 genotype (349 nucleotides, nt) and 12 sequences from 3 populations belonged to the 2100D0 genotype (400 nt) among the 16 determined sequences. A total of 87 points of mismatches were found by comparison with the most similar sequences in GenBank. Seventeen single-nucleotide polymorphisms (SNP) were detected, and 6 SNP-patterns in the 2100D0 genotype and 2 SNP-patterns in the 2134D51 genotype were identified based on SNP positions. In SNP-pattern 2, 10 SNPs were detected, but only 2 SNPs were found in SNP-pattern7. Meanwhile, one SNP-pattern was found from one RNA-sample, multi SNP-patterns were detected from other RNA-samples. Large numbers of SNP variants indicate that vast numbers of point-mutations on SBV have occurred since SBV invaded Korea and that SNP smay have been introduced individually over time. Thorough analysis of SNP variants will not only define the local infection-route, but also the relationships between SNP-pattern and SBV-pathogenic abilities.

• Korean Journal of Veterinary Service
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• v.38 no.1
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• pp.57-59
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• 2015

This study was carried out to investigate the Sacbrood virus (SBV) of Korean native honeybees causing serious damage in Jeonbuk area. Korean native honeybees completing the after overwinter 60 farms and March to April active phase adult bees and larvae 52 farms were collected from farms in 7 counties. Active phase of the adult bees 39 (75.0%) and larvae 24 (46.2%) farms was infected with SBV in 52 farms. This result indicate that SBV was the highest in Imsil-gun than other areas.

• Journal of Apiculture
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• v.33 no.4
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• pp.283-295
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• 2018

As Sacbrood virus (SBV), a causative agent of larval death and colony collapse in Apis cerana honey bee, is prevalent and poses one of the most significant threats to the Korean apiculture, development of methods to counter this viral disease is urgently needed. In this study we tested some SBV controlling methods, such as requeen, shook swam, adding Apis mellifera and spraying yogurt to SBV inoculated colony. Colony size measured by number of sealed brood and adult were evaluated every 15 days until two months while instances of recurrence were recorded up to five months after applying treatment methods. We also test the effects of yogurt on healthy and SBV-infected larvae at both in vitro reared larvae and colony level. Our result showed that all SBV controlling methods had similar success rates with respect to elimination of SBV clinical symptom up to 30 days post treatment. Mix-species and spraying yogurt method had similar pattern of sealed brood and adult number and higher than that of other SBV controlling methods up to 45 days post treatment. These two groups also showed the lower percentage of SBV recurrence (50% and 66.7%) at 120 days post treatment than other group that mostly colony had clinical symptom. Result on in vitro reared larvae challenged with yogurt showed that yogurt have neither harmless on healthy larvae nor remedial effect on SBV infected larvae. However, at colony level, colony in group received yogurt treatment removed significantly more SBV-infected larvae, SBV-killed larvae, and even healthy larvae in comparison to the control, suggested that yogurt could trigger the hygienic behavior of nurse bee. Our results recommended that it is practical in beekeeping by adding A. mellifera and spraying yogurt to control SBV in A. cerana colony.

• Korean Journal of Veterinary Service
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• v.35 no.2
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• pp.111-117
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• 2012

This study investigated the occurrence of honeybee diseases in Incheon area, at the point of great widespread of sacbrood disease in the country. Sixteen resident beekeeping apiaries; 3 native honeybee and 13 European honeybee apiaries were selected for this research. Over 20 adult bees were evenly collected from the most colonies of each apiary three times (March, June, November) within a year. In this work, 13 honeybee diseases including 7 viral diseases, 2 bacterial diseases, 2 fungal diseases, and 2 parasitic diseases were detected by preliminary inspections and PCR. As a result, viral infections were confirmed at 34 among 48 apiaries (70.8%) over the entire examination period. Parasitic diseases showed the highest detection rate of 45.8%, which are detected in 44 among 96 cases. In the seasonal prevalence, 30 cases (15.6%) of 7 pathogens were detected from 14 apiaries in March, 50 cases (24.0%) of 9 pathogens and 56 cases (26.9%) of 9 pathogens were detected from all apiaries in June and November, respectively. Nosema was shown to be the most prevalent pathogen from March to November, followed by sacbrood virus (SBV) and stonebrood. The spread of SBV infection in Incheon would be under-estimated by the increasing of detection rate over the time. Especially, Chinese sacbrood virus was detected from 4 European honybee apiaries, but clinical symptoms were not found. No chalkbrood, acute bee paralysis virus, and chronic bee paralysis virus were detected in this study. The effective therapy and preventive measures should be prepared for beekeeping industry.

• Journal of Apiculture
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• v.33 no.4
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• pp.269-275
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• 2018

Beekeeping status of Apis cerana with emphasis of experiences overcoming sacbrood virus disease are presented. Social bee fauna are rich in Vietnam with 6 honeybee species (Apis laboriosa, Apis dorsata, Apis mellifera, Apis cerana, Apis andrenifomis, Apis florea); 8 stingless bee species (Trigona laeviceps, Trigona ventralis, Trigona pagdeni, Trigona gressitti, Trigona fuscobalteata, Trigona capenteri, Trigona scintillans Trigona iridipenis) and 2 bumble bee species (Bumbus haemorrhoidalis, B. breviceps). All of them are native except A. mellifera which was introduced in1887. These bees are slated for conservation by the Ministry of Agriculture & Rural Development. Honey and other bee products are mainly harvested from 3 species including A. cerana, A. mellifera and A. dorsata. The manageable species (A. cerana and A. mellifera) are increasing in number, reaching about 1,500,000 beehives. Vietnam is the second largest honey exporter in Asia, with a total of about 48,000 tons of honey exported to the international market in 2014. A. cerana plays an important role in poverty alleviation in mountainous and remote areas of Vietnam. Honeybee suffers from various diseases of Sacbrood virus disease (SBV), European foulbrood (EFB), Nosema, and parasitic mites of Tropilaelaps mercedes and Varroa destructor. Most of these diseases can be resolved with biocontrol methods. For the parasitic mites, Vietnamese beekeepers usually apply formic acid.

• Korean Journal of Veterinary Service
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• v.36 no.2
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• pp.147-150
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• 2013

This study was carried out to investigate the prevalence of honeybee (Apis mellifera) disease in cheonan and asan area. From September to November in 2012, 33 samples were collected from 33 apiculture farms in the regions and reverse transcriptase-polymerase chain reaction (RT-PCR) and polymerase chain reaction (PCR) was conducted. Among 33 samples, prevalence rate was 42% in Sac Brood Virus (SBV), 52% in Nosema, 21% in American foulbrood (AFB), 70% in European foulbrood (EFB), 97% in Stonebrood, 3% in Chalkbrood. The result indicate that stonebrood was most prevalent disease in apiculture farms in cheonan and asan area.