• 대한수의학회지
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• 제43권1호
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• pp.139-144
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• 2003

A chitinase cDNA named CHT1 was cloned from the hard tick, Haemaphysalis longicornis, and the enzymatic properties of its recombinant proteins were characterized. The CHT1 cDNA encodes 930 amino-acid (aa) residues including a 22 aa putative signal peptide, with the calculated molecular mass of the putative mature protein 104 kDa. The E coli-expressed rCHT1 exhibited weak chitinolytic activity against $4MU-(GlcNAc)_3$. The rCHT1 protein with higher activity was obtained using recombinant Autographa californica multiple nuclear polyhedrosis virus (AcMNPV), which expresses rCHT1 under polyhedrin promoter. These findings suggest that the rCHT1 expressed in baculovirus-mediated Sf 9 cells has a high activity than E coli-expressed rCHT1.

• 약학회지
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• 제35권2호
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• pp.111-118
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• 1991

A comparative study was performed on two different strains of Leishmania major, chloroquine sensitive strains (Chl$^{S}$) and its mutant chloroquine resistant strains (Chl$^{R}$). Chl$^{R}$ strains were obtained at 5$\times$$10^{-4}$M chloroquine. Remarkable differences were observed at the initial chloroquine uptake in Chl$^{R}$ and Chl$^{S}$, i.e., the rate of uptake was very reduced in Chl$^{R}$ (Km values were 70 nM and 125 nM, respectively). Influx and accumulation of chloroquine were also compared between wild type and mutant. An increasing tendency in both influx and accumulation of chloroquine was shown in Chl$^{S}$, but Chl$^{R}$ demonstrated a rapid release after a little uptake (influx) at the early stage. This result is thought to be basis of their resistance for Chl$^{R}$ strains.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2004년도 수산관련학회 공동학술대회 발표요지집
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• pp.505-505
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• 2004

Pathological conditions of Pacific oysters were surveyed in some coastal areas of Korea. Samples of 30 to 45 oysters were collected in Kamakman, Masan and in Gosung Bay. Protozoan includes gregarine-like organism, Marteilioides chungmuensis, Haplosporidium; ciliates Ancitrocoma and Metazoa (termatode, nematode, copepod) were observed in samples from most of the sampling areas. Marteilioides chungmuensis was found in all sampling sites. Protozoan, Halosporidium sp. and Ancistrocoma sp. occurred in oysters from Gosung Bay (year 2000) with very low prevalence. Trematode Gymnophalloides was frequently found in oysters from all studied areas. Inflammation was frequently observed in oysters infected with M. chungmuensis and Pseudomyicola. The damaged structures were found in digestive tubes of oysters infected by Halosporidium sp. and Pseudomyicola sp. Some of the parasites and pathological status could associate with the conditions of oysters and the environment.

• Parasites, Hosts and Diseases
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• 제52권4호
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• pp.345-353
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• 2014

Babesia gibsoni is an intraerythrocytic apicomplexan parasite that causes piroplasmosis in dogs. B. gibsoni infection is characterized clinically by fever, regenerative anemia, splenomegaly, and sometimes death. Since no vaccine is available, rapid and accurate diagnosis and prompt treatment of infected animals are required to control this disease. Over the past decade, several candidate molecules have been identified using biomolecular techniques in the authors' laboratory for the development of a serodiagnostic method, vaccine, and drug for B. gibsoni. This review article describes newly identified candidate molecules and their applications for diagnosis, vaccine production, and drug development of B. gibsoni.

• Parasites, Hosts and Diseases
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• 제57권2호
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• pp.185-189
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• 2019

To identify the component(s) involved in cell cycle control in the protozoan Giardia lamblia, cells arrested at the G1/S- or G2-phase by treatment with nocodazole and aphidicolin were prepared from the synchronized cell cultures. RNA-sequencing analysis of the 2 stages of Giardia cell cycle identified several cell cycle genes that were up-regulated at the G2-phase. Transcriptome analysis of cells in 2 distinct cell cycle stages of G. lamblia confirmed previously reported components of cell cycle (PcnA, cyclin B, and CDK) and identified additional cell cycle components (NEKs, Mad2, spindle pole protein, and CDC14A). This result indicates that the cell cycle machinery operates in this protozoan, one of the earliest diverging eukaryotic lineages.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.45-48
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• 2005

• 한국패류학회:학술대회논문집
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• 한국패류학회 1999년도 추계학술발표대회요약집(한국패류학회)
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• pp.12-12
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• 1999

• Parasites, Hosts and Diseases
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• 제56권1호
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• pp.93-100
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• 2018

Some small mammals occur as household pests and harbour a number of parasites that could be of public health importance. This study profiled the helminth and protozoan parasites in trapped small mammals within and around human dwelling places (houses) located across 4 major towns (Auchi, Benin, Ekpoma, and Uromi) and environs in Edo state, Nigeria. Six genera (Apodemus sp., Crocidura sp., Mastomys natalensis, Mus musculus, Rattus sp., and Sorex sp.) were identified from 502 trapped small mammals. Overall, M. musculus (71.9%) and Rattus rattus (20.1%) were the most frequently trapped. In total, on examination of blood, gastrointestinal contents, and brain tissues, 12 helminth taxa (Angiostrongylus sp., Aspicularis sp., Capillaria sp., Gongylonema sp., Heterakis spumosa, Hymenolepis diminuta, Hymenolepis nana, Mastophorus muris, Moniliformis moniliformis, Nippostrongylus brasiliensis, Strongyloides sp., Trichosomoides sp., and Trichuris sp.), and 6 protozoan parasites (Babesia sp., Trypanosoma lewisi, Plasmodium sp., Eimeria sp., Isospora sp., and Toxoplasma gondii) were isolated. Most prevalent helminths with relatively heavy mean intensity were Strongyloides sp. and Heterakis spumosa, while Plasmodium, Eimeria, and Isospora were the most prevalent protozoan parasites. Generally, intrinsic factors like sex and age had marginal influence on the rate and burden of infection in M. musculus and R. rattus. Although the infection rate and prevalence of zoonotic parasites were low, they were largely recovered in rodents from Ekpoma. This study elucidates the public health implication of the presence of zoonotic parasites in these small mammals.

• 대한수의학회지
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• 제38권2호
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• pp.359-365
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• 1998

This study was conducted to isolate the protozoan parasite Babesia gibsoni by intraerythrocytic culture method of micoraerophilous stationary phase(MASP) and evaluate the possibility of application for the detection of B gibsoni in canine babesiosis. Also, indirect fluorescent antibody test(IFAT) and thick blood smear(giemsa stain), direct light microscopy (DLM), as control diagnostic tests, were conducted to compare diagnostic effects between MASP, IFAT and DLM. The results obtained from this study were summarized as follows. The protozoan parasite B gibsoni multiplied in 24-well polystyrene plate containing 1.2ml of canine red blood cell suspension in RPMI 1640 medium(pH 7.0) which is contained 20~40% normal canine serum(NCS) under the MASP condition of 5% $CO_2$ and 95% air at $37^{\circ}C$ incubator. Under the above MASP culturing system the percentage of parasitized erythrocytes(PPE) after incubation for 9 days reached the peak. The levels of PPE in MASP culture were shown more higher by exchanging the medium at 24 hour intervals. The parasite were purely isolated from MASP culture of canine red blood cells collected from dogs(pit bullterrier) infected with B gibsoni naturally. Among the total of 83 heads of pit bullterrier blood samples the positive rate was 32 heads(38.5%) in DLM, 45 heads(54.2%) in IFAT and 42 heads(50.6) in MASP culture. In negative cases of IFAT and DLM the isolation rates of B gibsoni by MASP culture were 16 heads(42.1%) of 38 heads and 16 heads(28.6%)% of 56 heads, respectively. From this study it was suggested that MASP culture method by RPMI 1640 medium was a reliable and useful diagnostic test for the diagnosis of B gibsoni infections in canine babesiosis.

• Parasites, Hosts and Diseases
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• 제56권6호
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• pp.589-596
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• 2018

Ticks are the vectors of various pathogens, threatening human health and animal production across the globe. Here, for the first time we detected Ricketssia spp., Borrelia spp. and protozoan in ticks from Poyang Lake region in Jiangxi Province of eastern China. In 3 habitat categories and on 12 host species, 311 ticks from 11 species were collected. Haemaphysalis longicornis was the predominant species, accounting for 55.63%, followed by Rhipicephalus microplus, Haemaphysalis flava and Ixodes granulatus. Of the collected ticks, 7.07% were positive for tick-borne pathogens, and H. longicornis and H. flava were found to be co-infected with Ricketssia spp. and protozoan. H. flava was the most detected positive for tick-borne pathogens, whereas H. longicornis had the lowest infection rate, and the difference in infection rates between tick species was significant (${\chi}^2=61.24$, P<0.001). Furthermore, adult ticks demonstrated remarkably greater infection rate than immature ticks (${\chi}^2=10.12$, P=0.018), meanwhile ticks on Erinaceidae showed significantly higher positivity than ticks collected on other host species (${\chi}^2=108.44$, P<0.001). Genetic fragment sequencing and analyses showed at least 4 pathogen species presence in ticks, namely Borrelia yangtzensis, Rickettsia slovaca or Rickettsia raoultii related genospecies, Babesia vogeli and Hepatozoon canis or Hepatozoon felis related genospecies. The finding indicates that the abundant ticks can carry diverse pathogens in Poyang Lake region, and pathogen infection is highly related to species, vertebrate hosts and life stages of ticks.