• 한국어병학회지
• /
• 제18권2호
• /
• pp.119-124
• /
• 2005

Two species of myxosporean parasites - Parvicapsula anisocaudata and an unidentified myxosporean were found in the lumina of renal tubules and the tubular epithelium, respectively, from cultured olive flounder, Paralichthys olivaceus in Korea. The latter was also seen in interstitial tissue of spleen and interrenal gland of the head kidney. Group of pseudoplasmodia of P. anisocaudata were firmly attached on the epithelium of renal tubules through pseudopodia. In the renal tubule epithelium, a group of unidentified myxosporean trophozoites, which were 2-3 times larger than intraluminal trophozoites of P. anisocaudata, was observed. The parasites being burst out into the lumen was occasionally encountered with partial break of the epithelium. Although infection of P. anisocaudata and unidentified myxosporean parasites did not induce any cellular reaction of the host, occlusion of renal tubules and rupture of renal epithelium would impact negatively on the renal functions of severely infected fish.

• 한국어병학회지
• /
• 제31권2호
• /
• pp.123-129
• /
• 2018

Parvicapsula anisocaudata, a myxosporean parasite, is presumably one of causative agents of emaciation in olive flounder Paralichthys olivaceus in Korea. In this study, we report a case of unusual abdominal distension due to exceptionally enlarged liver in farmed olive flounder. For the identification of the causative agent, bacteria and nucleic acids of virus that are possibly present were attempted to isolate from internal organs of five fish sampled from a fish farm in Jeju. Although a few bacterial colonies were isolated from some samples, there was no evidence that fish were primarily affected by virus and/or bacteria. From histopathological analysis, myxosporean were found in almost all internal organs, particularly in the stomach. The causative agent was identified as P. anisocaudata by sequencing a part of small subunit rRNA. This study contains a very unusual case of olive flounder heavily and systemically infected with P. anisocaudata, showing excessively enlarged liver with a small amount of ascitic fluid.

• 한국수산과학회지
• /
• 제54권5호
• /
• pp.660-667
• /
• 2021

In recent years, myxosporean infection from the cultured olive flounders Paralichthys olivaceus, have been frequently observed in Jeju island, South Korea. This study aimed to compare histopathological and molecular-biological methods of examining myxosporean infection from these flounders. Samples were obtained from affected individuals exhibiting emaciation or abdominal distention and a polymerase chain reaction (PCR) indicative of Parvicapsular anisocaudata, Enteromyxum leei and Kudoa septempunctata were initiated. Histopathological examination were conducted with H&E stained tissue sections, and then in-situ hybridization (ISH) reaction were processed with selected sections using P. anisocaudata, E. leei, K. septempunctata and Scuticociliate probes. Renal and intestinal tissue degeneration were common symptoms associated with all samples. Sever glomerular and renal tubular degeneration were evident, as were intestinal epithelial desquamation and spore formation in the epithelial cells. The results of conventional PCR analysis and ISH reactions revealed differences, and we suspect that various microparasites may have been associated with the symptoms manifested.

• 한국어병학회지
• /
• 제17권3호
• /
• pp.179-189
• /
• 2004

Morphological structure and sporogenesis of myxosporean parasite, Parvicapsula anisocaudata from cultured olive flounder, Paralichthys olivaceus were examined by light and transmission electron microscopies. Numerous round early stages, spindle-shaped disporic or monosporic pseudoplasmodia, asymmetrical thin-walled mature spores were found inthe lumen of renal tubule and urinary bladder. Long pseudopodia or short projections from cytoplasm of pseudoplasmodia make the parasite attach firmly to host tissues. Spore development was mono- or disporous with no pansporoblast formation. Sporoplasmic cell was partially surrounded by two capsulogenic cells, and capsulogenic cells were enveloped by two flattened valvogenic cells. Capsulogenesis and valvogenesis followed general patterns seen in that of other myxosporean.

• 한국어업기술학회:학술대회논문집
• /
• 한국어업기술학회 2002년도 춘계 수산관련학회 공둥학술발표회
• /
• pp.551-552
• /
• 2002

• 한국어병학회지
• /
• 제33권1호
• /
• pp.55-62
• /
• 2020

본 연구에서는 점액포자충에 의한 넙치의 여윔증 치료 후보물질을 탐색하기 위하여, Coxi-stop, Coxiclin 및 BLEAN80 등의 제품을 사용하여 in vitro 및 in vivo 실험을 실시하였다. 톨트라주릴이 주성분인 Coxi-stop의 경우, BF-2 cell을 사용한 in vitro 실험에서 점액포자충의 활성을 감소시키는 결과를 보였고, cell lysis와 같은 세포 독성 현상이 나타나지 않았다. In vivo 실험에서 Coxi-stop을 사용하여 약욕한 실험군은 대조군에 비하여 누적폐사율이 낮게 나타났으며, 이것은 톨트라주릴이 어류 기생충성 질병에 치료 효과가 있다는 기존의 보고와 유사한 결과이다. 본 연구에서는 톨트라주릴이 넙치의 여윔증 치료제로서 가능성이 있는 후보 물질이라는 것을 제시한다.

• 한국어병학회지
• /
• 제34권2호
• /
• pp.161-168
• /
• 2021

Quantitative analysis of myxosporean parasites (Enteromyxum leei and Parvicapsula anisocaudata) were performed using real-time PCR on the internal organs (head kidney, body kidney, intestine, spleen, brain, liver, heart, muscle, blood, and eye) of emaciated Paralichthys olivaceus from farm-A. The highest DNA copy number of E. leei was shown in the intestine (1.3 × 10⁸ copies/mg tissue) of emaciatied P. olivaceus and DNA copy number in the other internal organs (1.3 × 10³~4.6 × 10⁵ copies/mg tissue) showed lower than in intestine. From the result of real-time PCR for P. anisocaudata, it was considered mildly infected, due to the low DNA copy numbers of the head kidney (1.3 × 10³ copies/mg tissue) and body kidney (9.1 × 10³ copies/mg tissue). In order to investigate whether myxosporean parasites can be detected in a non-invasive way, quantitative analysis of E. leei and P. anisocaudata from rearing water of three farms were performed by real-time PCR. The DNA copy number of E. leei from rearing water of farm-A and farm-B were 8 × 10⁴ and 5 × 10⁵ copies/L, respectively. However, it was not detected in farm-C. For P. anisocaudata from rearing water, farm-A, farm-B and farm-C showed 0, 2.0 × 10⁶ and 5.1 × 10⁶ copies/L, respectively.

• 한국어병학회지
• /
• 제31권2호
• /
• pp.101-107
• /
• 2018

여윔증상이 나타난 양식장(farm-B 및 farm-C)의 넙치 및 여윔증상이 나타나지 않은 양식장(farm-A) 넙치의 각 내부 장기(신장, 장, 비장, 뇌 및 간)를 대상으로 점액포자충 Parvicapsula sp.의 양적 분석을 real-time PCR 방법을 사용하여 각각 실시하였다. 여윔증상을 보였던 farm-C의 넙치 신장에서 가장 높은 DNA copy number ($1.7{\times}10^7copies/mg$ tissue)를 보였고, farm-B의 넙치에서는 모든 내부 장기에서 낮은 수치가 나타났으며, farm-A의 넙치에서는 모든 내부 장기에서 음성 결과를 나타내었다. 동일한 시료를 사용한 PCR 및 병리조직학적 분석에서도 real-time PCR에서의 결과와 같은 양상을 보였다.

• Parasites, Hosts and Diseases
• /
• 제57권2호
• /
• pp.127-134
• /
• 2019

Sinuolinea capsularis Davis, 1917 is myxosporean that infect the urinary system of the host fish. Insufficient morphological and molecular data of S. capsularis exits, and it is therefore difficult to make an accurate identification of the parasite. We tried a series of morphological and molecular analysis to identify an myxosporean isolated from urinary bladder of cultured olive flounder, Paralichthys olivaceus, from Jeju island in the Republic of Korea. Some of them were observed under a light microscope and SEM, and remain samples were used molecular and phylogenetic analysis. Mature spores were subspherical, measuring $13.9{\pm}0.6{\mu}m$ in length and $13.8{\pm}0.8{\mu}m$ in width. Two spherical polar capsules on opposite sides in the middle of the spore had a diameter range of $4.3{\pm}0.4{\mu}m$. Scanning electron microscopy revealed that spores a severely twisted the suture line. By the morphological comparison and analysis, it was identified as S. capsularis. In addition, we obtained the partial 18S rDNA of S. capsularis and first registered it in NCBI. Phylogenetic analysis showed that S. capsularis clustered with Zschokkella subclade infecting the urinary system of marine fish, and it supported the infection site tropism effect on phylogeny of marine myxosporeans as well as the origin of Sinuolinea is not monophyly.

• 한국어병학회지
• /
• 제36권2호
• /
• pp.395-401
• /
• 2023

Myxosporeans are widespread cnidarian endoparasites in marine and freshwater ecosystems and several species were reported to be a threat to cultured fish causing serious diseases with mass mortality. In the present study, we found a myxosporean species in the genus Thelohanellus from the gills of the cultured common carp (Cyprinus carpio) fingerling for the first time in Korea. The morphological observation showed 500 ㎛ ~ 1 mm size, oval to circular shaped plasmodia containing spores which are pyriform at the anterior end and round at the posterior end (average size 20.1 ㎛ × 9.1 ㎛), with 5 to 6 turns of a single polar filament located in the polar capsule with an average size of 10 ㎛ × 4.6 ㎛. The 18S rRNA sequence was closest to the sequence of T. wangi among Thelohanellus species infecting gills but was not completely identical. Based on the morphological characteristics and molecular analysis results, we classified the present myxosporean parasite as Thelohanellus sp., temporarily. The prevalence and infection intensity of Thelohanellus sp. in the common carp fingerling were very high, which was thought to be the main cause of high mortality.