• 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.

• 대한본초학회지
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• 제22권4호
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• pp.145-153
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• 2007

Objective : Although chronic non-bacterial prostatitis is a common disease, it is very difficult to treat effectively. Toosendan fructus(TOF) has been traditionally used in treatment of abdominal pain and parasite. In this study, we investigated the therapeutic effects and action mechanism of Toosendan fructus (TOF) in the rat model of non-bacterial prostatitis induced by castration and testosterone treatment. Method : Eight-month-old rats were treated with $17{\beta}$-estradiol after castration for induction of experimental non-bacterial prostatitis, which is similar to human chronic prostatitis in histophatological profiles. Toosendan fructus(TOF) and testosterone were administered as an experimental specimen and a positive control, respectively. The prostates were evaluated by histopahological parameters including the epithelial score and epithelio-stromal ratio for glandular damage. Also, the prostates were observed by hematological alterations of WBC, RBC, hemoglobin, hematocrit and platelet. Results : While prostates of control rats revealed severe acinar gland atrophy and stromal proliferation, the rats treated with Toosendan fructus(TOF) showed a diminished range of the tissue damage. Epithelial score was improved in Toosendan fructus(TOF) than that of the control. The epithelio-stromal ratio was lower in Toosendan fructus(TOF) when compared to that of the control. Also, the examination of bloods were not observed hematological change. Conclusions : These findings suggest that Toosendan fructus(TOF) may protect the glandular epithelial cells and may take hematological safety. We concluded that Toosendan fructus(TOF) may could be a useful remedy agents for treating the chronic non-bacterial prostatitis.

• Parasites, Hosts and Diseases
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• 제55권2호
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• pp.129-135
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• 2017

A total of 60 samples were collected from 35 swimming pools in Beijing, China, and the presence of Cryptosporidium and Giardia were investigated. The results showed that 16.7% and 15.0% of samples were positive for Cryptosporidium oocyst and Giardia cysts, respectively, with a mean concentration of 0.30 oocysts/10 L and 0.27 cysts/10 L. The oocysts and cysts were found to have higher rates of occurrence in August than in May. Genotyping confirmed the presence of Cryptosporidium hominis, C. parvum, and Giardia assemblages A and B, all of which were associated with human infections. The predominant species/assemblages were C. hominis and Giardia assemblage A. Analyses of the relationships between parasite oocysts/cysts, indicator bacteria, and physical-chemical parameters revealed that there was no correlation between 2 parasites and fecal bacterial indicators, whilst there was a significant correlation between protozoa and urea concentration, which indicates that urea concentration rather than fecal bacterial indicators might be an appropriate index for chlorine-resistant protozoa in swimming pools. This study provides useful information to improve the safety of swimming pool water and deduce the risk of protozoan infections.

• Asian-Australasian Journal of Animal Sciences
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• 제27권2호
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• pp.278-283
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• 2014

Cecropins (Cec) are antibacterial peptides and their expression is induced in a pig intestinal parasite Ascaris suum by bacterial infection. To explore the usefulness of its activity as an antibiotic, CecP4 cDNA was prepared and cloned into the pPICZ B expression vector and followed by the integration into AOX1 locus in Pichia pastoris. The supernatants from cell culture were collected after methanol induction and concentrated for the test of antimicrobial activity. The recombinant P. patoris having CecP4 showed antimicrobial activity when tested against Staphyllococcus aureus in disc diffusion assay. We selected one of the CecP4 clones (CecP4-2) and performed further studies with it. The growth of recombinant P. pastoris was optimized using various concentration of methanol, and it was found that 2% methanol in the culture induced more antibacterial activity, compared to 1% methanol. We extended the test of antimicrobial activity by applying the concentrated supernatant of CecP4 culture to Pseudomonas aeruginosa and E. coli respectively. Recombinant CecP4 also showed antimicrobial activity against both Pseudomona and E. coli, suggesting the broad spectrum of its antimicrobial activity. After improvements for the scale-up, it will be feasible to use recombinant CecP4 for supplementation to the feed to control microbial infections in young animals, such as piglets.

• 한국어병학회지
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• 제25권3호
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• pp.231-241
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• 2012

2007년~2011년 하절기에 국내 동 서 남해안과 제주의 육상양식장, 가두리 및 축제식 양식장에서 사육중인 넙치 (Paralichthys olivaceus), 조피볼락 (Sebastes schlegeli), 참돔 (Pagrus major), 흰다리새우 (Litopenaeus vannamei) 의 총 2,413마리에 대하여 세균과 기생충의 감염현황을 조사하였다. 조사기간(2007년~2011년) 사이 어종별 병원체에 대한 감염양상을 종합하면, 기생충과 세균의 단독감염이 혼합 감염에 비하여 비교적 높게 나타났으며, 단독감염 가운데 기생충이 세균보다 감염률이 높은 경향을 나타내었다. 조사기간 동안 넙치, 조피볼락, 새우에서 Vibrio spp. (V. harveyi, V. ichthyoenteri, Vibrio sp.)가 가장 우점종으로 검출된 세균의 위치를 차지하였으며, 참돔에서는 Vibrio sp.와 P. damselae가 우점종 세균으로 검출되었다. 조사기간 동안 가장 우점종으로 검출된 기생충은 넙치에서 스쿠티카충 (M. avidus)과 트리코디나충 (Trichodina sp.), 조피볼락에서 아가미흡충 (M. sebastes), 참돔에서 아가미흡충 (M. tai), 새우에서 섬모충 (Zoothamnium sp.) 으로 나타났다.

• 한국수산과학회지
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• 제32권1호
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• pp.62-67
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• 1999

1992, 1993년에 경남 통영, 거제 및 전남 여수 등 남해안 주요 굴 채묘 어장에서 참굴, Crassostrea gigas의 극심한 채묘 부진 현상이 발생하여 이에 대한 원인 구명의 일환으로 각 시험 어장 서식 모패 중의 난소기생충 감염율을 조사하고 감염난 및 비감염난에 대한 발생 비교 시험을 실시하였다. 그리고, 모패 중 난의 건강도 판정 및 발생 가능성 추정을 위하여 난 지질 함량을 측정하였다. 또한, 각 채묘 부진 해역에서 채집한 굴 유생 중의 세균의 오염정도와 오염균의 세균상 등을 조사하였다. 1992년 8월에서 1993년 9월 사이 경남 통영 저산, 거제 오수 및 전남 여수 경도, 굴전 지역 굴 암컷 모패의 난소기생충, Marteiliodes chungmuensis 감염 율은 각각 $11.8\~100\%,\;14.3\~100\%,\;$15.4\~93.3\%,\;12.5\~91.7\%$였으나, 충남 대천의 자연산 굴 암컷 모패에서는 난소기생충이 검출되지 않았다. 한편, 난소기생충에 감염된 난의 세포질 내에서는 직경 78$\~$80nm의 바이러스성 입자 (virus-like particle)가 관찰되었다. 난소기생충에 감염된 난을 사용한 인공 발생 실험에서 기생충에 감염된 난은 수정이 불가능하였으며, 동일 생식소에 감염난과 함께 있었던 정상난도 수정은 가능하였으나, $80\%$ 이상이 형태적으로 비정상적인 발생을 하였고, 정상적으로 발생하여 D형 및 초기각정기까지 도달한 유생도 외부 각부터 녹기 시작하여 연체부까지 파괴되는 세포 괴사 현상을 나타내며 전량 폐사하였다. 채묘 부진 현상이 발생한 통영 저산 양식산 참굴의 난지질 함량은 3.8ng/egg이었으나, 충남 대천 자연산의 난지질은 6.2ng/egg였다. 한편, 발생 전 낮은 난 지질 함량을 나타내었던 통영 저산 산의 난은 정상적인 수정, 발생 단계를 거쳐 수정 7일째 초기각정기까지는 발달하였으나, 이후 발생이 진전되지 못한 채 수정 10일째 전량 폐사하였다. 각 시험어장에서 채취한 참굴 유생의 단위개체당 생균수는 거제 오수가 8,100으로 가장 높았고, 통영 저산이 98, 여수 굴전이 5.5로 나타났다. 각 시험어장에서 채수한 해수 중의 생균수는 여수 굴전이 14,000/ml으로 가장 높았으며, 거제 오수와 통영 저산이 각각 370, 260/ml으로 비슷하였다. 채묘 부진 해역에서 채집된 패류 유생 중의 세균상은 Pseudomonas속 및 그 유사세균이 $53.3\~87.1\%$로 절대 우점종을 차지하였다.

• 한국식물병리학회지
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• 제14권6호
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• pp.714-719
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• 1998

Obligate bacterial parasite attacking Heterodera glycines was firstly found from Chungju soybean field in Korea. Diameters of sporangium and central body were 5.6 ${\mu}{\textrm}{m}$ and 1.9 ${\mu}{\textrm}{m}$ under light microscopy (LM), and 3.9 ${\mu}{\textrm}{m}$ and 1.8 ${\mu}{\textrm}{m}$ under transmission electron microscopy (TEM). Endospore showed cup-shaped with smooth-type exosporium without peg-like thickening in polar area under SEM and TEM. Bacteria completed its life cycle in female of soybean cyst nematode after adhering on cuticle of second-stage juvenile. From these results, the Pasteuria found from Chungju was identified with P. nishizawae.

• 한국식물병리학회지
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• 제14권6호
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• pp.710-713
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• 1998

Spatial distribution in soil and seasonal population changes of Pasteuria nishizawae first found in Korea from soybean cyst nematode were studied. P. nishizawae infested in 61% of areas in a soybean field; in an average, about 0.3% of 46 cysts and 17.6% of 9 juveniles per 100 g soil were infested with the bacterium. The highest percentages of spore-attached nematodes were found in July (75%) and between soil depth of 11~20 cm. The number of spores per juvenile was positively correlated with the percentage of juveniles with spores (r=0.4203; P＜0.0133), but negatively correlated with the number of juveniles in soil (r=-0.3499; P＜0.042). P. nishizawae completed its life cycle in cyst and produced 1.7$\times$105 spores per cyst.

• 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.

• The Plant Pathology Journal
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• 제35권1호
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• pp.51-62
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• 2019

A great variable response was observed when PP-3 and PP-J encumbered with 116 populations of root knot nematode (RKN) at two different temperatures ($25{\pm}2^{\circ}C$ and $30{\pm}2^{\circ}C$) and concentrations ($10^4$ and $10^5$ spores/ml). The PCR reaction amplified intergenic region between cytochrome oxidase subunit II gene (COII) and large subunit of rRNA gene (lrRNA) of the mitochondrial genome of different RKN species. The primer C2F3 and 1108 identified M. incognita with the highest frequency (52.6%) followed by M. javanica (36.8%) and M. arenaria (10.5%). The sizes of PCR products were 1.7 kb for M. incognita and M. javanica populations while populations of M. arenaria produced 1.1 kb fragment. The digestion with Hinf I yielded three different fragment length patterns on 1.5 % agarose gel. From current research it is concluded that intra-Meloidogyne genetic variability exist in RKN populations which have better encumbrance with P. penetrans.