• Journal of Korean Society of Environmental Engineers
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• v.29 no.5
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• pp.533-539
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• 2007

Cell culture infectivity assay using HCT-8 cell was combined with most-probable-number technique to evaluate the inactivation of Cryptosporidium parvum by various disinfectants, including chlorine, ozone, and UV light. The assay was demonstrated to be as sensitive as animal infectivity assay, which has been considered the "gold standard" for assessing Cryptosporidium oocyst infectivity, and a valuable tool to evaluate inactivation of C. parvum by disinfectants. Bench-scale inactivation study showed that at the condition of $5^{\circ}C$ and pH 7.0, CT value of $1,250mg{\cdot}min/L$ by chlorine and $16mg{\cdot}min/L$ by ozone were required to achieve approximately 1.0 log inactivation of C. parvum, suggesting that even ozone could not be sufficient to inactivate C, parvum at low. temperature. Unlike chlorine and ozone, UV light is very effective to inactivate C. parvum, regardless of temperature. A UV light dose of 2 $mJ/cm^2$ provided at least 3 log inactivation of C. parvum.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.76-78
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• 2001

먹는 물에 존재하는 크립토스포리디움 및 지아디아등 기존의 표준 정수처리 공정에 의해 제거가 용이치 않은 원생동물 둥을 채집할 수 있는 미생물 검출 캡슐을 개발하였다. 본 장치의 여과필터는 고분자물질을 소재로 한 중공사 형태(Hollow Fiber Membrane)로 유효여과면적을 크게하였고, Pore size는 0.1㎛이다. 채집캡슐은 탁도에 따른 투과수량은 일차의 상관관계를 나타내며, 시간당 20ℓ를 투과시킬 때 탁도 7.0 NTU까지 가능함을 확인 할 수 있었다. 일차 시제품은 89.6-94.6%의 크립토스포리디움 및 72.6-78.6%의 지아디아 포낭을 회수하였고, 이차 시제품은 92.5-93.7%의 크립토스포리디움 및 81.3-88.2%의 지아디아 포낭을 회수하는 것으로 나타났다. 동일한 조건에서 외국제품은 84.0%의 크립토스포리디움 및 66.7%의 지아디아 포낭을 회수하는 것으로 나타났다.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.366-370
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• 1998

To determine the efficacy of immunotherapeutic agents, four female Holstein calves 7-day-old were inoculated per os with $1{\times}10^7$ C parvum oocysts (VRI-CN91). Each calf received twice daily oral dosage of 200-500ml of the immune bovine serum, immune bovine colostrum, mAb C6, and phosphate-buffered saline, respectively. Treatment was initiated 4 days postinfection and laster 3 days. The clinical sign of the calf treated with phosphate-buffered saline lasted 9 days after the initial treatment. The calves treated with those immunotherapeutic agents, however, showed decreased severity of diarrhea at day 3, 2, 5 after the initial administration, respectively. The calves treated with immunotherapeutic agents showed reduced parasite loads compared to control calf. These results suggest that oral passive immunotherapy with immune bovine colostrum and immune bovine serum may be a useful treatment approach.

• Parasites, Hosts and Diseases
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• v.31 no.3
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• pp.223-230
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• 1993

Monoclonal antibodies (Ub) against merozoites and sporozoites of the protozoan parasite Cryptosporidium pcnjum were examined for potential modulation of cryptosporidial infections in vivo by daily oral Ub administration to oocyst-inoculated neonatal mice. Monoclonal-treated neonatal mice were sacrified four and eight days post infection (pi) . Differences in infection rates were observed among the treatment groups at the p < 0.05 level. Suckling mice treated daily with orally administered mixtures of mAbs( ascitic fluids) showed significantly reduced parasite loads compared to control mice at flour and eight days pi, while suckling mice receiving mAb Cmg-3 alone showed signiacant differences only at 4 days Pi., suggesting that passive transfer of mAb may be of value in controlling cryptosporidial infections.

• Journal of Life Science
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• v.16 no.5
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• pp.729-733
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• 2006

Cryptosporidium is a waterborne pathogenic parasite which causes diarrhea. Immunomagnetic separation-immunofluorescent assay (IMS-IFA) has been a widely adopted for Cryptosporidium detection as standard method. However, this method does not provide information about viability or infectivity of Cryptosporidium. Therefore, many researchers have studied viability or infectivity analyses of Cryptosporidium with various methods such as vital staining, in vitro excystation, RT-PCR, cell culture, and mouse infection assay. In this study, two direct RT-PCR methods, cell culture RT-PCR and cell culture IFA were compared for sensitivity and other characteristics. The results showed that direct RT-PCR method with HSP70 genes had the highest sensitivity with detection up to 1 viable cell of Cryptosporidium. The infectious Cryptosporidium were detected up to 10 to 25 cells by cell culture methods in combination with RT-PCR and IFA. The infectious Cryptosporidium were apt to be quantified by cell culture IFA.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.534-539
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• 2006

In the ozone disinfection unit process of a piston type batch reactor with continuous ozone analysis using a flow injection analysis (FIA) system, the CT values for 1 log inactivation of Cryptosporidium parvum by viability assays of DAPI/PI and excystation were $1.8{\sim}2.2\;mg/L{\cdot}min$ at $25^{\circ}C$ and $9.1mg/L{\cdot}min$ at $5^{\circ}C$, respectively. At the low temperature, ozone requirement rises $4{\sim}5$ times higher in order to achieve the same level of disinfection at room temperature. In a 40 L scale pilot plant with continuous flow and constant 5 minutes retention time, disinfection effects were evaluated using excystation, DAPI/PI, and cell infection method at the same time. About 0.2 log inactivation of Cryptosporidium by DAPI/PI and excystation assay, and 1.2 log inactivation by cell infectivity assay were estimated, respectively, at the CT value of about $8mg/L{\cdot}min$. The difference between DAPI/PI and excystation assay was not significant in evaluating CT values of Cryptosporidium by ozone in both experiment of the piston and the pilot reactors. However, there was significant difference between viability assay based on the intact cell wall structure and function and infectivity assay based on the developing oocysts to sporozoites and merozoites in the pilot study. The stage of development should be more sensitive to ozone oxidation than cell wall intactness of oocysts. The difference of CT values estimated by viability assay between two studies may partly come from underestimation of the residual ozone concentration due to the manual monitoring in the pilot study, or the difference of the reactor scale (50 mL vs 40 L) and types (batch vs continuous). Adequate If value to disinfect 1 and 2 log scale of Cryptosporidium in UV irradiation process was 25 $mWs/cm^2$ and 50 $mWs/cm^2$, respectively, at $25^{\circ}C$ by DAPI/PI. At $5^{\circ}C$, 40 $mWs/cm^2$ was required for disinfecting 1 log Cryptosporidium, and 80 $mWs/cm^2$ for disinfecting 2 log Cryptosporidium. It was thought that about 60% increase of If value requirement to compensate for the $20^{\circ}C$ decrease in temperature was due to the low voltage low output lamp letting weaker UV rays occur at lower temperatures.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.11a
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• pp.205-206
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• 2004

국내 정수처리에 있어 기존 장티프스, 콜레라 등과 같은 병원성 세균의 소독 뿐만아니라 최근에는 지아디아, 크립토스포리디움과 같은 병원성 원생동물의 불활성화에 대하여 많은 관심을 가져야 하며 적정한 소독능을 확보하기 위해서는 정수지의 도류벽 설치, 용량확장, 수위비조절 및 잔류염소 농도 조절 등의 운영 및 시설개선이 필요한 것으로 판단된다.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.531-538
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• 2007

The effects of temperature, coagulants and pre-chlorination on the removal of turbidity and pathogenic protozoa by coagulation process were investigated using jar test of lab scale. In room temperature ($25^{\circ}C$), protozoa were removed over 1.0log at the proper concentration range of coagulants, and up to over 2log at the optimal concentration of coagulants. Considering the 1.5log target removal for Giardiain the processes of coagulation, sedimentation, and filtration, this results implies that the target could be satisfied. However, the removal of protozoa and turbidity was reduced, and optimal PAC concentration was narrowed in low turbidity and cold temperature ($5^{\circ}C$). These results suggest that the drop of coagulation efficiency may be occurred in winter if the conditions are not optimized. Despite the effect of water temperature, the relation of turbidity and protozoa removal appeared to be good. The various kinds of coagulants did not significantly affected for removals of turbidity and protozoa when the concentrations of $Al_2O_3$ were considered. Prechlorination did not increase or decrease the removal of turbidity and protozoa in optimum condition at room temperature, pH 7, 15mg/L of PAC concentration.

• Korean Journal of Microbiology
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• v.39 no.1
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• pp.27-35
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• 2003

No currently available methods to monitor pathogenic protozoa, Cryptosporidium and Giardia in environmental water come close to acceptable sensitivity, specificity and reproducibility, and so it has to be accompanied by thorough quality control and performance evaluation to credibly predict the distribution of them. We collected surface water samples from the Han River and spiked our prepared (oo)cysts, determined Matrix Spike recoveries using USEPA Method 1623 and considered what factors influence MS recovery and validity. As a result, average 46% of spiked oocysts and 60% of spike cysts were recovered, but repetitive sampling and statistical approach seemed to be necessary to determine the environmental pollution level of two protozoa as their variation coefficients was so much as 35oio and 26%. And MS recoveries with two acid dissociations during immunomagnetic separation were improved more 10% than that with one dissociations and the use of spiked suspension enumerated by flow cytometry instead of manual preparation enhanced the validity and reliability in spiking tests. Because fluorescence characteristics of (oo)cysts stained on well slides with FITC-labeled monoclonal antibodies and DAPI was not always same, well Elides from spiked field samples were helpful to evaluate the performance of staining. We found many (oo)cyst-like objects with typical fluorescence, not (co)cysts, from the Han River water samples, and then it was concluded that nuclei staining by DAPI (4',6-diamidino-2-phenylindole) and examination by Differential Interference Contrast Microscope should be critical for valid identification.

• Parasites, Hosts and Diseases
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• v.29 no.4
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• pp.315-324
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• 1991

Each of SPF chicken(Hi-Line strain, 2-day-old males) was inoculated with 2.5 or $5\times10^4$ oocysts by stomach tube. The oocyst was the medium type of Cryptosporidium previously isolated from Korean chicken origin, and passed in 2-day-old SPF chicken. The patterns of oocyst discharge were monitored daily, and in order to observe the ultrastructure of the developmental stages, the bursa of Fabricius of the chicken was examined by transmission electron microscopy (TEM) on the 12th day postinoculation. The prepatent period for 8 chicken was 5.9 days postinoculation on the average, and the patent period was 12.9 days. The number of oocysts discharged per day for the chicken was reached peak on day 12 postinoculation on the average. A large number of oocysts was found in fecal samples obtained from inoculated chicken on days 8~14 postinoculation. The ultrastructural feature of almost every developmental stage of the medium type from chicken was very similar to that of Cryptosporidium previously isolated from mammalia including human and birds except for the attachment site of C. tsuris to the mucus cell from mammalia, but dimension of the oocysts from fecal samples of the medium type was different from those of C. meleagridis and mammalia origin. The above results reveal that the medium type of Cryptosporidium of Korean chicken origin is identified as Cryptosporidium baileyi.