• 대한수의학회지
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• 제30권2호
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• pp.255-260
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• 1990

This study was conducted to examine the enteropathogens and clinical aspects of diarrhea of the 211 Korean native calves during the suckling period. The experimental results were summerized as follows: 1. The 206 Korean native calves (97.6%) were affected with diarrhea during the suckling period. 2. Of 156 diarrheal feces tested, Rotavirus were detected from 108(69.2%) feces of $K^+99$ E coli were detected from 23(14.7%) feces and Eimeria spp were detected from 33(21.2%) feces. But Salmonella spp and Cryptosporidium spp were not detected. 3. Rotavirus were detected from 2 to 84 days of life, $K^+99$ E coli were detected from 5 to 54 days and Eimeria spp were detected from 33 to 84 days of life. 4. Physical appearances of the diarrheal feces were not affected specifically according to the enteropathogens, but were affected by the severity of diarrhea and the diets.

• Parasites, Hosts and Diseases
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• 제58권2호
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• pp.129-134
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• 2020

In most developing countries, Dientamoeba fragilis infection is an obscure protozoan infection. We aimed to determine a frequency and clinical importance of D. fragilis infection in Taif, Saudi Arabia. A 1-year case control study included patients with gastrointestinal (cases, n=114) or non-gastrointestinal symptoms (controls, n=90). The fecal samples were examined with the classical parasitological methods for intestinal protozoa, and by real time PCR for D. fragilis. The infection by D. fragilis was detected in 5.8% by PCR and in 4.4% patients by microscopy. The infection was identified more in control group (n=9) than in cases (n=3); a sole infection in 11 patients and mixed with Giardia in 1 patient. The other enteric parasites detected were Blastocystis sp. (8.3%), Giardia sp. (5.3%), Cryptosporidium sp. (2.9%), Entamoeba histolytica (1.4%), Entamoeba coli (0.9%) and Hymenolepis nana (0.4%). Our results tend to reinforce the need to increase awareness of D. fragilis infection in Saudi Arabia.

• 대한수의학회지
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• 제59권1호
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• pp.33-36
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• 2019

This study examined complex infections with various enteropathogens and the genetic diversity of bovine norovirus (BNoV) in 932 fecal samples from diarrheic calves in South Korea. Overall, seventeen (1.8%) of the samples tested positive for BNoV following RT-PCR examination. All BNoV-positive samples were co-infected with other intestinal pathogens, including bovine Rotavirus, Giardia, Cryptosporidium, and Escherichia coli. The genetic diversity of the BNoVs shared high nucleotide identity (98.1-99.5%) and amino acid homology (93.5-98.1%) with genotype 2 BNoV (GIII.2) strains. In conclusion, BNoV infections with GIII genotypes were detected in complex infections of diarrheic calves in South Korea.

• 상하수도학회지
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• 제19권1호
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• pp.47-52
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• 2005

This study was conducted to evaluate the performance of submerged hollow fiber MF processes to treat secondary wastewater for water reuse. Specifically, membrane productivity and filtrate water quality were investigated under various operating conditions (i.e. flux, recovery, and backwash rate) at pilot-scale. Membrane fouling became more severe with increasing flux and recovery, suggesting that low flux operation (< 25 LMH) was desirable. At high flux operating(> 37.5 LMH), increasing backwash rate showed only limited success. The biofouling, quantified by PEPA and BFHPC, was also significant in wastewater reclamation, and biogrowth control by chlorine, were necessary to improve membrane productivity. Filtrate water qualities are in good compliance with water reuse regulations regardless of operating conditions (flux, recovery and backwash rate). Particle (e.g. turbidity) removal ranged from 89 to 98%, while only 11 to 21% of organics (e.g. NPDOC) were removed by MF membrane. Only small improvement in biostability (e.g. AOC) was achieved by MF system, and thus, without post disinfection, significant microorganisms might be present in the filtrate due to regrowth. Lastly, in order to further investigate pathogen removal, controlled microbial challenge tests were performed by monitoring Giardia, Cryptosporidium, bacteria and virus, and showed relatively good microbial removal.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.645-650
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• 2019

Despite differences in virulence between strains of Toxoplasma gondii, rapid and accurate genotyping methods are lacking. In this study, a method was developed to detect and genotype T. gondii in food and environmental samples using PCR and a novel peptide nucleic acid (PNA) melting array. An alignment of genome sequences for T. gondii type I, II, and III obtained from NCBI was generated, and a single nucleotide polymorphism analysis was performed to identify targets for PCR amplification and a PNA melting array. Prior to the PNA melting array, conventional PCR was used to amplify GRA6 of T. gondii. After amplification, the PNA melting array was performed using two different PNA hybridization probes with fluorescent labels (FAM and HEX) and quenchers. Melting curves for each probe were used to determine genotypes and identify mutations. A 214-bp region of the GRA6 gene of T. gondii was successfully amplified by PCR. For all T. gondii strains (type I, II, and III) used to evaluate specificity, the correct genotypes were determined by the PNA melting array. Non-T. gondii strains, including 14 foodborne pathogens and 3 protozoan parasites, such as Giardia lamblia, Cryptosporidium parvum, and Entamoeba histolytica, showed no signal, suggesting that the assay has a high specificity. Although this is only a proof-of-concept study, the assay is promising for the fast and reliable genotyping of T. gondii from food and environmental samples.

• 대한수의학회지
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• 제38권2호
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• pp.366-370
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• 1998

7일령의 송아지 4마리에 실험적으로 크립토스포리디움을 감염시키고 면역혈청, 면역초유 그리고 단크론항체(C6)을 투여하여 이들의 면역요법제로서의 효과를 측정하였다. 크립토스포리디움 감염후 4일째부터 3일간 하루 2회(200~500ml)씩 3종의 면역요법제를 송아지 1마리씩 각각 경구로 투여하였으며, 나머지 한마리의 대조송아지에는 인산 완충액을 경구로 투여하였다. 크립토스포리디움에 감염된 송아지들은 설사를 나타냈는데 대조송아지의 경우 감염후 3일째부터 9일간 설사증상을 나타냈다. 면역혈청, 면역초유 그리고 C6로 치료한 송아지들은 치료후 각각 3일, 2일, 5일째부터 정상에 가까운 분변을 배출하기 시작하였다. 면역혈청과 면역초유로 치료한 송아지들의 경우, 분변으로 배출되는 오시스트의 수가 대조송아지에 비해 현저하게 줄어들었다. 이러한 결과들은 실험에 제공된 면역요법제중 면역초유나 면역혈청이 크립토스포리디움에 감염된 송아지의 설사증상과 오시스트의 배출을 억제하는 효과가 있음을 나타내는 것이다.

• 한국식품과학회지
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• 제32권4호
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• pp.970-973
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• 2000

전남 도내 5개 지역과 광주시 근교 1개 지역에서 재배되고 있는 미나리의 안전성 평가를 위해 중금속 함유량과 기생충 감염 여부를 조사하였다. 그 결과 비교적 독성을 지니고 있는 중금속인 수은과 비소는 각각 흔적 수준과 극히 미량인 $0.003{\sim}0.01\;ppm$으로 나타났다. 납은 모든 지역에서 검출되지 않았으며, 카드뮴은 $0.013{\sim}0.036\;ppm$ 범위를 보였으며, 또한 농작물 생장에 필수원소로 작용하는 구리, 망간과 아연의 함유량은 $0.285{\sim}0.627\;ppm,\;1.337{\sim}12.884\;ppm,\;2.105{\sim}4.221\;ppm$이 검출되었다. 또한 미나리에서 흡충류인 간질과 간흡충, 수인성원 충류인 람블 편모충과 크립토스포리듐속 그리고 선충류인 회충과 십이지장충 6종에 대한 기생충 검사 결과 모두 검출되지 않았다.

• 한국환경보건학회지
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• 제27권4호
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• pp.15-24
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• 2001

The objective of this study it to evaluate the microbial safety in rapid sand filters adapted in most drinking water treatment plants. The potential pathogens to cause water quality problems Are presumed to be Giardia and Gryptosporidium. They look like particles in view of their size. It has been reported that if the number of particles (larger than 2 ${\mu}{\textrm}{m}$ in water) is less than 100 per mL and its turbidity is below 0.1 NTU, it is considered as a safe water in terms of pathogens. In order to achieve such a good water quality. filter-aids (chemicals) were added to the inlet-channel of filter and their effectiveness was evaluated on the basis of water quality factors such as turbidity and particle counting. This study was conducted in she three steps of experiment: jar test. pilot plant test and real water treatment plant test (P plant in seoul). The experiment reult of the P water treatment showed that cationic polyamine was the most effective in the removal of particles and turbidity at the does of 0.25 mg/L. The turbidity without filer-aids showed in the range of 0.12 ~0.17 NTU during filtration and 0.14 NTU on the average. However. with addition of polyamine, the turbidity represented below(or less than) 0.1 NTU after 20 min in the start of filtration and kept 0.08 NTU on the average. On the other hand, as for number of particles, while no filter-aids led to the range of 111 ~270 per mL and 190 on the average, addition of polydmine led to 113 per mL on talc average, and kept below100 per mL after 20 min in the start of filtration.

• 한국물환경학회지
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• 제24권6호
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• pp.793-800
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• 2008

Recently domestic drinking water industry has recognized membrane-based technology as a promising alternative for water treatment. To ensure successful application of membrane processes, the integrity of membrane systems should be maintained. According to US EPA guidance, the pressure decay test based on the bubble point theory is recommended to detect any membrane defection of which size is close to the smallest diameter of Cryptosporidium oocysts, $3{\mu}m$. Proper implementation of the pressure decay test is greatly affected by initial test pressure, and the interpretation of the test results is associated with upper control limit. This study is conducted to investigate various factors affecting determination of initial test prtessure and upper control limit, including membrane-based parameters such as pore shape correction factor, surface tension and contact angle, and system-based parameters, such as volumetric concentration factor and total volume of system. In this paper, three different hollow fibers were used to perform the pressure decay test. With identical initial test pressure applied, their pressure decay tendency were different from each other. This finding can be explained by the micro-structure disparity of those membranes which is verified by FESEM images of those membranes. More specifically, FESEM images revealed that three hollow fibers have asymmetry, deep finger, shallow finger pore shape, respectively. In addition, sensitivity analysis was conducted on five parameters mentioned above to elucidate their relation to determination of initial test pressure and upper control limit. In case of initial pressure calculation, the pore shape correction factor has the highest value of sensitivity. For upper control limit determination, system factors have greater impact compared to membrane-based parameters.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제2권1호
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• pp.85-92
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• 1999

저자들은 15세 된 남아와 8세된 남아에서 C. parvum에 의한 위장관염 2례를 경험하였으며 전자 현미경상으로 확진하여 보고하는 바이다. 향후 국내에서도 소아의 설사질환의 원인으로서 cryptosporidiosis에 대한 임상의들의 많은 관심이 요구된다.