• 한국임상수의학회지
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• 제24권4호
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• pp.588-592
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• 2007

The prevalence of E. coli(K99), Clostridium perfringens and Cryptosporidium parvum on acute diarrhea in suckling Korean native calves was evaluated in the field by a veterinary practice. In diagnosis, fecal samples were directly collected from calves that had diarrhea between 2 and 98 days of age. 40 samples were analyzed in October, 2006 and December, 2006. Clostridium perfringens and Cryptosporidium parvum were detected in 15(37.5%) and 4(10.0%) of the samples from diarrhetic calves, respectively. However, E. coli(K99) was not detected in the samples from diarrhetic calves. There was no significant difference(p>0.05) between October(5, 25.0%) and December(10, 50.0%) in incidence of detected Clostridium perfringens from diarrhetic calves. On the other hand, significant differences (p<0.05) in the detection rate of Clostridium perfringens were found between the within 1 month age and all other age groups. In the detection of Cryptosporidium parvum, there was no significant difference(p<0.05) between October (2, 10.0%) and December(2, 10.0%) in the incidence of detected Cryptosporidium parvum from diarrhetic calves. These results suggest that causative agents of calf diarrhea occurred frequently with Clostridium perfringens infection than E. coli(K99) and Cryptosporidium parvum.

• Parasites, Hosts and Diseases
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• 제49권4호
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• pp.423-426
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• 2011

In the genus Cryptosporidium, there are more than 14 species with different sizes and habitats, as well as different hosts. Among these, C. parvum and C. hominis are known to be human pathogens. As C. parvum can survive exposure to harsh environmental conditions, including various disinfectants or high doses of radiation, it is considered to be an important environmental pathogen that may be a threat to human health. However, the resistance of other Cryptosporidium species to various environmental conditions is unknown. In this study, resistance against ${\gamma}$-irradiation was compared between C. parvum and C. muris using in vivo infection in mice. The capability of C. muris to infect mice could be eliminated with 1,000 Gy of ${\gamma}$-irradiation, while C. parvum remained infective in mice after up to 1,000 Gy of ${\gamma}$-irradiation, although the peak number of oocysts per gram of feces decreased to 16% that of non-irradiated oocysts. The difference in radioresistance between these 2 Cryptosporidium species should be investigated by further studies.

• 한국물환경학회지
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• 제24권6호
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• pp.817-822
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• 2008

In order to identify various Cryptosporidium species in environment, nested PCR-RFLP and DNA sequencing method were used. The sensitivity of nested PCR-RFLP based on 18s rRNA gene was shown to 1 oocyst. Therefore, we applied nested PCR-RFLP method to environmental samples. As a result, only 4 samples out of 8 samples confirmed as Cryptosporidium parvum by standard method of Cryptosporidium were identified as Cryptosporidium parvum by nested PCR-RFLP and DNA sequencing method. The rest of 4 samples among 8 samples were identified as Cryptosporidium muris, Cryptosporidium bailey. Therefore, in addition to standard method of Cryptosporidium, supplementary verification through nested PCR-RFLP and DNA sequencing should be needed to give more accurate information about risk of Cryptosporidium.

• 한국미생물·생명공학회지
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• 제17권5호
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• pp.494-498
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• 1989

AIDS 환자의 치명적인 2차 감염을 유발하는 Cryptosporidium parvum 의 Infective stage 인 sporozoites의 단일군 항체를 분리하였다. Oocysts를 효소처리하여 sporozoites를 excystation시킨 후 Isopycnic percoll gradients를 이용하여 sporozoites를 순수분리한 후 단일군 항체 생산을 위한 항원으로 사용하였다. 두 달된 BALB/c 쥐를 immunize한 후 splenocytes와 P3-X63-Ag8 myeloma cells를 융합시킨 후 hybridoma 기술을 이용해 Kor1(IgGl), Ea2(Ig2a) 두 clones을 분리하였으며 정제된 sporozoites를 SDS-PAGE로 분리한 후 Western blot을 이용하여 단일군 항체 Kor1과 Ea2는 20,000 daltons 크기의 항원을 인식하였다. Immunofluorescent assay에서 단일군 항체가 sporozoites 표면에 반응하는 것으로 보아 20-kDa 단백질 항원은 sporozoites 표면에 위치하는 항원으로 밝혀졌으며 C. parvum에 감염되었을 때 항체생성에 관여하는 중요 항원 중 하나일 것으로 추정되었다.

• 한국물환경학회지
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• 제21권1호
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• pp.7-13
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• 2005

With the appearance of pathogenic microorganisms, which were resistant to free chlorine, the significant attention to the necessity of powerful alternative disinfection methods such as ozone, chlorine dioxide, LTV irradiation to inactivating pathogens has been increased in water treatment. Among these alternative disinfection methods, ozone is well known as strong biocidal method and the usage of ozone is also increasing in Korea. However, in Korea, there has been no report on the quantitative study of Cryptosporidium parvum with ozone and its evaluation in advanced drinking water treatments. This study reports on the methodology for predicting the ozone inactivation of Cryptosporidium parvum by ozone disinfection in advanced drinking water treatment. The method is based on the fact that a specific inactivation level of microorganisms is achieved at a unique value of ozone exposures, independent of ozone dose and type of water, and quantitatively described by a delayed Chick-Watson model. The required values ${\bar{C}}T$ for 2 log inactivation of Cryptosporidium parvum was $6.0mg/L{\cdot}min$ and $15.5mg/L{\cdot}min$ at $20^{\circ}C$ and $5^{\circ}C$, respectively. From this obtained Cryptosporidium parvum inactivation curves and calculated ${\bar{C}}T$ values of advanced drinking water treatment water in Korea with FIA (Flow injection alaysis), we can predict that water treatment plant can achieve a 1.1~1.8 log inactivation and 0~0.4 log inactivation at $20^{\circ}C$ and $5^{\circ}C$, respectively. This methodology will be useful for drinking water treatment plants which intend to evaluate the disinfection efficiencies of their ozonation process without full scale test and direct experiments with Cryptosporidium parvum.

• Parasites, Hosts and Diseases
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• 제30권4호
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• pp.259-262
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• 1992

국내 마우스에서 분리하여 계대중인 Cryptosporidium parvum 원충이 송아지에 감염되는지 알아보기 위하여 25일령의 한우 송아지에 1×106개의 오오시스트를 감염시킨 결과 점종 후 4일 째부터 분변 내에 오오시스트를 배출하였다. 오오시스트의 배설은 8일간 지속되었고, 그 수는 인충 점종 후 6일째에 가장 많았다(분변 gram당 4.9×105개 오오시스트). 감염된 송아지의 분변 내로 오오시스트가 배출되는 동안 분변의 성상은 정상이었다. 이상의 결과로 볼 때 국내 마우스에서 분리된 C. parvum은 송아지에게도 교차감염이 이루어져 숙주특이성이 없음을 알 수 있었다.

• Parasites, Hosts and Diseases
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• 제42권1호
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• pp.45-47
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• 2004

To investigate the infection status of pigs with Cryptosporidium parvum, 589 fecal samples were collected from pigs raised at farm in Chungcheongbuk-do and Chungcheongnam-do. Of the 589 pig fecal samples, 62 (10.5%) were positive for C. parvum. The area showing the highest positive rate was Dangjin-gun, Chungcheongnam-do (14.0%), and the lowest (0%) Salmi-myon, Chungcheongbuk-do. The positive rate of C. parvum in Judok-eup increased from 12.7% in the winter to 22.1 % in the summer. The results of this study suggest that the pigs may be a source of human C. parvum infection.

• Parasites, Hosts and Diseases
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• 제47권3호
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• pp.293-297
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• 2009

Improved methods for detection of Cryptosporidium oocysts in environmental and clinical samples are urgently needed to improve detection of cryptosporidiosis. We compared the sensitivity of 7 PCR primer sets for detection of Cryptosporidium parvum. Each target gene was amplified by PCR or nested PCR with serially diluted DNA extracted from purified C. parvum oocysts. The target genes included Cryptosporidium oocyst wall protein (COWP), small subunit ribosomal RNA (SSU rRNA), and random amplified polymorphic DNA. The detection limit of the PCR method ranged from $10^3$ to $10^4$ oocysts, and the nested PCR method was able to detect $10^0$ to $10^2$ oocysts. A second-round amplification of target genes showed that the nested primer set specific for the COWP gene proved to be the most sensitive one compared to the other primer sets tested in this study and would therefore be useful for the detection of C. parvum.

• Journal of Microbiology
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• 제34권4호
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• pp.379-383
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• 1996

Cryptosporidium parvum causes a life-threatening diarrhea in acquired immunodeficiency syndrome (AIDS) patients. THe sporozoite stage of C. parvum has been known to be a target in treating cryptosporidiosis in AIDS patients as it is an extracellular stage. A sporozoite was ultrastructurally observed. It has a creascent shape with a rounded posterior end and a tapering body. The compact nucleus was located at the posterior end. A monoclonal antibody was produced, which recognized a 43 kDa of sporozoite antigens in a western blot analysis and showed the surface labeling in immunofluorescence.

• Parasites, Hosts and Diseases
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• 제43권3호
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• pp.111-114
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• 2005

The present study investigated the prevalence rate of Cryptosporidium parvum as a cause of diarrhea. We examined 942 stools of unidentified reasons occurring in patients in whom no immunosuppression had been detected. We examined the stools for Cryptosporidium parvum via modified acid-fast staining. The clinical records of all of the positive patients were then analyzed. Nine ($1\%$) of the stools among the 942 diarrheal patients were positive for C. parvum. The positive rate in the males was $1.1\%$ (6/522) and the positive rate of the females was $0.7\%$ (3/420). Age distribution revealed that the highest positive rates were in patients in their sixties, with a positive rate of $2.5\%$ (4/158). In the clinical tests, levels of c-reactive protein, erythrocyte sedimentation rates, and neutrophil proportions were normally increased in the peripheral blood, whereas the lymphocyte proportion exhibited a tendency towards decrease. The pathological findings were compatible with an inflammatory reaction in the host.