• Biotechnology and Bioprocess Engineering:BBE
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• 제6권2호
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• pp.95-99
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• 2001

Giardia lamblia is a parasitic protozoa which is transmitted in the form of a cyst through untreated water and also treated drinking water. Since its presence in water has led to frequent outbreaks of giardiasis and death in many countries, the removal and disinfection of this protozoan cyst from the water supply are of great concern for public health. This study examined the disinfection characteristics of G. lamblia cysts isolated from a Korean patient with giardiasis. When using sodium hypochlorite including 5 or 10 ppm chlorine, the killing rate was initially rapid, however, the disinfection slowed down and a 3log reduction could not be achieved even after 2h. The disinfection effectiveness was also reduced at a lower temperature, thereby implying that the risk o a giardiasis outbreak will be higher in the winter season. A CT (concentration$.$time) curve was constructed based on the results with sodium hypochlorite for use in designing and predicting disinfection performance. The organic chlorination disinfectant SDIS (sodium dichloroisocyanurate) produced a lower pH and a much higher residual effect than sodium hypochlorite. The disinfection of cysts by SDIC continued steadily throughout 2h of contact, although the initial killing rate was lower than that with sodium hypochlorite.

• 한국환경과학회지
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• 제5권1호
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• pp.61-69
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• 1996

The combined wastewater of municipal landfill leachate and municipal sewage was treated using several sets of bench-scale aerated circulating system including porous media. Investigated items in this experiment were the dominant protozoa and metazoa in this system, the variation of microfauna relationship between operating condition and dominant genera. Also considered the factors determining dominant genera and their role. The outcome of this research is as follows; 1. Aspidisca, Vorticella, Truhellophyllum, Lecane, Philodina, Cyclops were mainly appeared prior to combinding leachate, while Trachelocerca, Bodo, Glaucoma were the dominant genera after combinding leachate. 2. As to metazoa, Nematode and Philodina were not influenced by 5oA leachate mixing ratio, meanwhile Crustacea has high sensitivity for increased leachate mixing ratio and it was not appeared in 5% leachate mixing ratio. 3. The appropriate treatability could'nt be expected at the above 10% leachate mixing ratio. Especially, in the condition of 20% leachate mixing ratio, all of the microfauna were affected damage seriously on their existence. Meanwhile hydraulic retention time, substrate loading rate and slut자e production rate didn't give notable influence on increasing the number of microfauna. 4. As to protozoa, saprozoic and holozoic species were appeared commonly and polysaprobic species were dominent. 5. Filamentous organsms were nearly not affected by leachate mixing. It seems that they could live without any trouble at the 10% leachate mixing ratio, if the substrate is sufficient. 6. Diversity of microfauna had a reducing trernd as the sewage was mixed with leachate.

• Parasites, Hosts and Diseases
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• 제58권2호
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• pp.147-152
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• 2020

Malaria is a potent burden on public healthcare worldwide due to requiring rapid diagnosis and treatment. Nowadays, prompt diagnosis with rapid diagnostic tests (RDTs) has been widely accepted as an effective diagnostic technique in malaria-endemic countries, primarily due to their easy operation, fast output, and straightforward interpretation. The global availability and use of RDTs have gradually grown over recent decades as field-applicable diagnostic tests for the reliable confirmation of malaria infection and proper case management. This study was conducted to evaluate diagnostic performance of 3 commercially available malaria RDT kits : BIOCREDIT^TM Malaria Ag Pf(pLDH), Malaria Ag Pf(pLDH/pHRPII), and Malaria Ag Pf/Pv(pLDH/pLDH) (where pLDH and pHRPII stand for plasmodium lactate dehydrogenase and histidine-rich protein 2, respectively) for the specific detection of Plasmodium falciparum. A total of 1,129 blood samples including 95 blood samples, confirmed as vivax malaria infection by microscopic examinations and a nested-PCR method, were tested for falciparum malaria infection. The overall sensitivity and specificity of Malaria Ag Pf(pLDH/pHRPII), Malaria Ag Pf/Pv(pLDH/pLDH), and Pf(pLDH) for P. falciparum were 99.0% and 100%, 95.8% and 100%, and 100% and 100%, respectively. It is proposed that the 3 RDT kits perform reliable level of diagnostic accuracy of detection for P. falciparum parasites.

• Parasites, Hosts and Diseases
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• 제58권5호
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• pp.543-550
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• 2020

Mosquitoes are globally distributed and important vectors for the transmission of many human diseases. Mosquito control is a difficult task and the cost of preventing mosquito-borne diseases is much lower than that for curing the associated diseases. Thus, chemical control remains the most effective tool for mosquito. Due to the long-term intensive use of insecticides to control mosquito vectors, resistance to most chemical insecticides has been reported. This study aimed to investigate the relationship between insecticide resistance and target site mutation of L1014 kdr and G119 ace alleles in 5 species/species group of mosquitoes (Aedes vexans, Ae. albopictus, Anopheles spp., Culex pipiens complex, and Cx. tritaeniorhynchus) obtained from 6 collection sites. For Anopheles spp., the proportion of mosquitoes with mutated alleles in L1014 was 88.4%, homozygous resistant genotypes were observed in 46.7%, and heterozygous resistant genotypes were observed in 41.8%. For the Cx. pipiens complex and Cx. tritaeniorhynchus species, homozygous resistant genotypes were found in 25.9% and 9.8%, respectively. However, target site mutation of L1014 in the Ae. vexans nipponii and Ae. albopictus species was not observed. Anopheles spp., Cx. pipiens complex, and Cx. tritaeniorhynchus mosquitoes were resistant to deltamethrin and chlorpyriphos, whereas Ae. vexans nipponii and Ae. albopictus were clearly susceptible. We also found a correlation between the resistance phenotype and the presence of the L1014 kdr and G119 ace mutations only in the Anopheles spp. population. In this study, we suggest that insecticide resistance poses a growing threat and resistance management must be integrated into all mosquito control programs.

• 한국해양학회지:바다
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• 제4권4호
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• pp.349-362
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• 1999

본 연구에서는 미세오손생물 군집 형성에 있어서 원생동물의 역할을 파악하기 위하여 초기 미생물막 형성과 미세오손생물 군집의 형성 및 부착과정, 부착 박테리아에 대한 원생동물의 포식영향 등이 연구되었다. 이를 위하여 인천내항과 외항(해경부두), 실험실 등에서 부착실험을 10~30일간 계속적으로 수행하였다. 인천내항 실험에서 박테리아와 편모충류는 실험 시작 6시간내에 미생물막을 형성하기 시작하였고 섬모충류는 9시간 경과시에 빈모류가 2 cells $mm^{-2}$ 출현하였다. 부착오손생물인 따개비 Balanus albicostatus의 유생은 실험 첫날부터 부착하기 시작하였다. 수괴가 안정된 인천내항에서 편모충류는 13일경 최대 465 cells $mm^{-2}$ 출현하였고, 섬모충류는 11 일째 63 cells $mm^{-2}$이 최대로 출현하였다. 인천외항에서 편모충류는 초기에 최대 223 cells $mm^{-2}$ 출현하였고, 섬모충류는 5일째 최대 39 cells $mm^{-2}$ 출현하여 인천내항보다는 외항에서 미생물막이 빠르게 발달하였으나 원생동물 출현 개체수는 작았다. 미생물막에 출현한 편모충류는 대부분 자서성인 Metromonas종류와 Bodonids종류였고, 섬모충류는 초기에는 소형 유종섬모충류 종류와 빈섬모충 Strombidium종류였고, 후에는 빈섬모충 Strombidium viridae(60 ${\mu}m$)와 부착성 Suctoria인 Acineta, turherosa가 출현하였다. 오손생물 군집은 따개비 유생이 초기부터 부착하여 7일째 18 개체 $cm^{-2}$ 까지 증가하였다. 이때 따개비 성체가 출현하기 시작하고 9일째부터는 따개비 사체가 발견되기 시작하였다. 이외에 오손생물로 강장동물 Anthozoa sp., 참굴(Crassostrea gigas)유생, 갯지렁이 유생 등이 실험시작 3일 후부터 부착하기 시작하였다. 부착판에 서식하는 요각류 Harpacticus sp. 등과 단각류 등은 미생물막이 잘 발달된 7일 이후에 출현하기 시작하였다. 미생물막 형성에는 알루미늄판이 유리판과 아크릴판보다 다소 유리하였고, 오손생물 군집과 부착판 서식생물 군집의 형성에는 유리판이 알루미늄판 보다 유리하였다. 미생물막 박테리아에 대한 원생동물의 섭취율은 낮은 편이나 포식율은 0.058 $h^{-1}$로 비교적 높아 원생동물이 미생물막 박테리아 개체군 사망에 큰 영향을 미치는 것으로 나타났다.

• 한국동물학회:뉴스레터
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• 제12권2호
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• pp.86.1-86
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• 1995

• 한국동물학회:학술대회논문집
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• 한국동물학회 1995년도 한국생물과학협회 학술발표대회
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• pp.132.1-132
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• 1995

• 한국동물학회:학술대회논문집
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• 한국동물학회 1997년도 공동 춘계학술대회
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• pp.27-27
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• 1997

No Abstract, See Full Text

• 한국환경과학회지
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• 제5권2호
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• pp.187-194
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• 1996

The present study was performed to elucidate the distribution of protozoans according to the actual conditions of soil pollution around Ulsan industrial complexes, Korea. Samples were collected from the top-soils of 13 localities in eight times during the period from 16 April 1994 to 14 January 1995. As a result of this study, total 11 species of hypotrichous ciliated protozoa were identified and analyzed. These hypotrichs are 6 species of stichotrichine hyporichs ( Keronopsis sp., Pseudourostyla sp., Hoiriiticha syivatica, Hipiosticha multistylata, Hoios-ticha sp. and ParuroleFitus sp.) and 5 species of sporadotrichine hypotrichs (Oxyricha sp., Steinla sp., Histriculus cavicola, Hemisincirra sp. and Gonostomum auiili). Of these 11 species, 4 species (Keronopsis sp., Pseudourostyla sp., Holosticha sp. and Hemisincirra sp.) are reriorted for 1%e first time from Korea. All the sampling localities could be grouped in three zones by the cluster analysis with the abundance and distribution of protozoans. This result is approximately coincide with the ionation by the concentration of heavy metals.

• 한국수산과학회지
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• 제29권6호
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• pp.856-861
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• 1996

The occurrence of TTX in ciliated protozoa was investigated in order to clarify tetrodotoxin (TTX) accumulation mechanisms in marine organisms. Tissue culture bioassay, HPLC, and GC-MS analyses confirmed the occurrence of TTX in Euplotes mutabilis and also in bacteria isolated from the culture medium. Fluorescently labeled bacteria (FLB) were prepared with those bacteria, and predation by E. mutabilis was observed. The results indicated that TTX in bacteria can be transferred to higher trophic levels through the food chain.