• 한국잠사곤충학회지
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• 제28권1호
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• pp.54-60
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• 1986

야외곤충에 대한 미포자충의 감염여부와 곤충에서 검출된 미포자충의 누에에 대한 감영성 조사 결과는 아래와 같다. 1. 채집한 66종의 야외곤충으로부터 미포자충이 검출된 야외곤충은 똥쉬파리, 꿀벌, 배추흰나비(유충), 아이노각다구, 등록색잎벌레, 벗나무풍뎅이, 노랑테불나방, 밀잠자리, 먼지벌레 및 벼잎벌레 등 10종이었다. 2. 추출된 미포자들을 크기에 따라 분류한 바 똥쉬파리로부터는 3종, 그리고 다른 곤충으로 부터는 각기 다른 1종의 미포자충이 검출됨으로써 총 12종의 미포자충이 분리되었다. 3. 똥쉬파리, 꿀벌 및 배추흰나비(유충)에서 검출된 미포자충들을 누에에의 교우감영성을 실험한 바 어느 것도 교유감염이 나타나지 않았다.

• 한국어병학회지
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• 제36권2호
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• pp.303-310
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• 2023

Yellow goosefish (Lophius litulon) is one of the important commercial fisheries target species in Korea, and commonly consumed as braised or stew. The microsporidian Spraguea is known to infect the nervous system of lophiid fish, forming numerous visible whitish xenomas. This parasite is commonly found in lophiid fish worldwide, but there is no information on the infection status of this parasite in Korea. We obtained commercially available chopped packs of lophiid fish from several fish markets and investigated their prevalence of infection. The isolated xenomas were crushed and purified as mature spore suspension. Microscopic observation and PCR were conducted to visualize and identify them. The host fish was also identified by DNA bar cording analysis. All the specimens were heavily infected and microscopic observation with Giemsa or Chromotrope 2R stain revealed tiny oval shapes of typical microsporidian spores. PCR analysis targeting the partial SSU rDNA showed that our specimen belongs to the genus Spraguea clade. But clear identification at the species level was not possible, due to the insufficient information of gene sequences available in GenBank. In addition, all of our host fish specimen was identified as yellow goosefish. This is the first report of a microsporidian parasite Spraguea infection in yellow goosefish from Korea.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권1호
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• pp.1-9
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• 2003

The silkworm, Bombyx mori, is prone to infection of various pathogenic organisms. Pebrine, one of the deadliest disease of silkworm caused by highly virulent parasitic microsporidian, Nosema bombycis has been understood since long. Infections of the disease range from chronic to highly virulent and can result in complete loss to the sericulture industry. Several strains and species of microsporidians have since been isolated from the infected silkworms; the disease is becoming increasingly more and more complex. Epizootiology, development of immunodiagnostic kit, use of chemotherapy and thermotherapy techniques has been addressed for identification and control of the disease. A technique of delayed mother moth examination, which plays a decisive role in the detection of the disease and harvestation of stable cocoon crop, has been described. An attempt has been made to review briefly the literature available on various aspects of the pebrine disease in order to develop efficient model(s) for the prevention and control of the disease and to suggest future avenues of investigation in the field of pebrine disease management.

• International Journal of Industrial Entomology and Biomaterials
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• 제26권1호
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• pp.1-12
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• 2013

The commercial rearing of polyphagous Indian tasar silkworm, Antheraea mylitta Drury being practiced on naturally grown primary food plants like Terminalia arjuna, (Arjun) Terminalia tomentosa (Asan), and Shorea robusta (Sal) available in the tropical forests of central India, at times, is seriously affected by the disease- Pebrine, caused by Nosema sp., a microsporidian pathogen. The present investigation on comparative larval, silk gland weight and also cocoon parameters in Pebrine-free and Pebrine-infected ecorace of tasar silkworm Antheraea mylitta Drury (Daba TV), illustrates the tasar silkworm larvae infected with pebrine disease causing heavy losses to the economy of the silk industry.

• 한국잠사곤충학회지
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• 제26권2호
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• pp.1-6
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• 1984

미포자충 포자의 정제법을 개발하고 포자표면의 혈청학적 반응을 구명하기 위하여 수행한 시험결과를 요약하면 다음과 같다. 1. 미포자충 포자의 분리정제는 예비원심-percoll 평형밀도원심-세척의 3단계법이 우수하였고, 분리정제된 포자는 극사추출에 나쁜 영향도 받지 않았다. 2. 포자의 형태는 K79 포자가 장타원형(장단경비 2.76)이고 N. bombycis는 단타원형(장단경비 2.07)으로 양포자가 상이하였다. 3. 형광항체 간접법에 의하여 항 N. bombycis 포자혈청에 대하여는 N. bomvycis 포자만이 강한 형광을 발현하였으나 항 K79 포자의 혈청에 대하여는 10배희석구에서는 양포자 모두 강하게, 20배 이상 희석구에서는 약하게 형광을 발현하였고 K79 포자의 특이항체가 포자외각에 인정되었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제12권2호
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• pp.87-93
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• 2006

Multiplication and spore production of three microsporidia viz., Nosema bombycis, Nosema sp. 1 and Nosema sp. 2 in fifth instar larval tissues of silkworm, Bombyx mori L. in two seasons with distinct temperature regimes were studied. Nosema sp. 2 produced significantly (P < 0.01) higher number of spores in various tissues. Among the tissues, spore production was highest in silk gland, followed by fat body and gut. Spore production was significantly (P < 0.01) higher in season-II (Average temperature $29.4{\pm}1.1^{\circ}C$). Maximum spore production was observed 25 days post inoculation (p. i.) in season-I (Average temperature $18.9{\pm}1.1^{\circ}C$), whereas in season-II, it was 14 days p. i. In season-I, spore production was low up to 21 days p. i., then increased sharply. In season-II, there was a steady increase in spore production. The results indicate that the microsporidian multiplication is tissue specific and extremely sensitive to temperature at which the host is reared. It also reveals that, silk gland, fat body and gut are the most appropriate tissues for microscopic identification of microsporidia in the larval stage.

• International Journal of Industrial Entomology and Biomaterials
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• 제18권2호
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• pp.83-89
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• 2009

Multiplication and spore production of three microsporidia(Nosema bombycis, Nosema sp. 1 and Nosema sp. 2) in selected tissues of pupa and adult of silkworm, Bombyx mori L. were studied in two seasons (SI, SII) with distinct temperature (SI: $20.1{\pm}0.8^{\circ}C$ and SII: $25.1{\pm}0.7^{\circ}C$) regimes. Multiplication of the microsporidia followed a logistic pattern with a lag phase, an exponential phase and a stationary phase. In SII, spore production was significantly (P<0.01) higher in various tissues. Highest spore production was observed 30 days post inoculation (p.i.) in SI and in SII, it was $21{\sim}23$ days p.i. Spore production was significantly (P<0.01) higher in the gut tissues than other tissues. Nosema sp. 2 registered significantly (P<0.01) higher spore production in both the seasons compared to Nosema bombycis and Nosema sp. 1. Results indicate that the multiplication and spore production of microsporidia are tissue specific and extremely sensitive to the temperature at which the host is reared. Through this study, the precise day that the spore numbers of the microsporidia are maximized can be predicted in both pupa and adult in case the infection is initiated in the first instar.

• International Journal of Industrial Entomology and Biomaterials
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• 제17권2호
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• pp.173-180
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• 2008

The influence of temperature and relative humidity in infection and cross-infection of Nosema bombycis and N. mylitta respectively in mulberry silkworm, Bombyx mori L. on larval mortality, multiplication of pathogens, larval weight and growth rate in three different seasons were studied. Seasons were selected in such condition, when very less fluctuations between minimum and maximum temperature and minimum and maximum relative humidity ($25{\sim}28^{\circ}C$ and $65{\sim}72%$ R.H) was observed i.e., season-1. Fluctuations between minimum and maximum temperature were less ($28.05{\sim}34.50^{\circ}C$) but R.H % was more ($55{\sim}81%$) in season-2. Fluctuations between minimum and maximum temperature and R.H % were more ($20.00{\sim}40.5^{\circ}C$ and $64.00{\sim}90.00%$) in season-3. Growth rate of microsporidian-infected silkworm is directly related to the prevailing temperature and relative humidity in silkworm. Silkworm can tolerate slight variation of temperature but slight variation of relative humidity disfavours the development of silkworm and favours the multiplication of pathogens.

• 한국어병학회지
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• 제16권1호
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• pp.23-30
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• 2003

On September in 1998, a microsporidian infection was recognized in ayu, Plecoglossus altivelis, farmed on Kyongnam province of South Korea. Cumulative mortality was around 10% in 10 days. Infected fish which were piping for air near the surface of the water or in the asphyxic, lethargic condition revealed darkening of body and abdominal distention. Numerous whitish nodules up to 3mm in size were observed throughout most of body organs and tissues including gill, operculum, peritoneal wall and organs. Xenomas were also histologically confirmed in multiple internal organs with the evidences suggesting circulatory disturbance. Based on the morphology of spore and xenoma, and the distribution of xenomas in organs and tissues, this disease was diagnosed to be a microsporidiosis caused by Glugea plecoglossi. The mortality might be deeply related to the local circulatory disturbance by xemonas rather than the mechano-chemical effect of xenomas on adjacent tissues.

• 한국수산과학회지
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• 제56권1호
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• pp.133-139
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• 2023

The advantage of biofloc technology (BFT) in aquaculture is in the prevention of pathogenic transmission. In this study, we performed an investigation on viral, bacterial, and microsporidian parasite infections targeting a total of 194 whiteleg shrimp Litopenaeus vannamei reared in seven BFT-farms on the west coast of Korea in 2021. Hepatopancreatic and cuticular epithelium and pereiopods tissues of shrimp were tested for the four pathogens, Enterocytozoon hepatopenaei (EHP), Vibrio parahaemolyticus causing Acute Hepatopancreatic necrosis disease (VP_AHPND), white spot syndrome virus (WSSV), and hepatopancreatic parvovirus (HPV). The microsporidian parasite EHP was detected in the hepatopancreatic tissue of BFT whiteleg shrimp in the Ganghwa region, whereas no other pathogenic bacteria or virus was detected on the shrimp in the seven BFT-farms. As a result of bacterial flora in the rearing water of BFT whiteleg shrimp using DNA microbiome technology, V. chemaguriensis and V. alfacsensis were contained at 0.05% and 0.01%, respectively, but no VP_AHPND was detected. These findings will serve as a basis for supporting safe BFT-aquaculture of whiteleg shrimp.