• Parasites, Hosts and Diseases
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• 제52권4호
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• pp.435-438
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• 2014

The disinfectant effects (DEs) of 10 types of chemicals, defined by their ability to destroy or inhibit oocysts and consequently prevent sporulation of Eimeria tenella field isolate, were evaluated in vitro. Correct species assignments and sample purities were confirmed by the singular internal transcribed spacer (ITS)-PCR analysis. A total of 18 treatments were performed, and the disinfection suppression levels were 75.9% for 39% benzene + 22% xylene (1:10 dilution), 85.5% for 30% cresol soup (1:1 dilution), and 91.7% for 99.9% acetic acid (1:2 dilution) group. The results indicate that acetic acid, cresol soup, and benzene+xylene are good candidates for suppression of E. tenella oocyst sporulation.

• Parasites, Hosts and Diseases
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• 제47권2호
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• pp.171-174
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• 2009

The antigen location of Cryptosporidium parvum, which stimulates antibody formation in humans and animals, was investigated using infected human sera. Immuno-electron microscopy revealed that antigenicity-inducing humoral immunity was located at various developmental stages of parasites, including asexual, sexual stages, and oocysts. The amount of antigen-stimulating IgG antibodies was particularly high on the oocyst wall. The sporozoite surface was shown to give stimulation on IgG and IgM antibody formation. Trophozoites implicated the lowest antigenicity to humoral immunity, both IgG and IgM, by showing the least amount of gold labeling. Immunogold labeling also provided clues that antigens were presented to the host-cell cytoplasm via feeder organelles and host-parasite junctions.

• 한국가금학회지
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• 제48권4호
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• pp.297-318
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• 2021

Coccidiosis is a major parasitic disease in the poultry industry, with great economic implications worldwide. It is a ubiquitous protozoan infection caused by several species of the genus Eimeria (host-specific) that colonize and reproduce in the intestine of birds, ultimately altering the health and performance of the flock. At present, several methods are used to diagnose coccidiosis in poultry, including field and laboratory techniques (intestinal lesion scoring, oocyst counting in feces, and biochemical and molecular diagnosis). Traditionally, diagnosed flocks have been treated either by vaccination to improve the active immunity of the birds against coccidiosis or supplementation of prophylactic anticoccidials to ameliorate the deleterious effects of coccidiosis. However, these methods has certain drawbacks such as vaccine-induced coccidiosis, drug resistance, and residual drug accumulation in the host. Consequently, alternative safe anti-coccidial agents, including the use of phytogenic compounds, have been explored for preventing coccidiosis. Here, we provide a simple overview of the literature on poultry coccidiosis by focusing on the etiology, diagnostic practices, and preventive measures.

• Parasites, Hosts and Diseases
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• 제28권1호
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• pp.31-38
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• 1990

실험용 마우스(ICR)에 프레드니솔론을 주어 인공적으로 면역억제시키면서 Cryptosporidium 발현 여부를 7주 동안 관찰한 바 다음과 같은 결과를 얻었다. 면역 억제 1주 후부터 마우스 대변에서 Cryptosporidium의 Oocyst (크기 440 ㎛)가 검출되었고 2주 후부터 마우스가 사망하기 시작하였다. 대변에서 oocyst가 검출된 마우스의 소장 절편을 H&E 염색하여 광학현미경으로 관찰한 결과 Cryptosporisium은 공장 하부에서 호발하였으며 장 융모의 점막 상피세포 표면에 점같이 붙은 모습으로 무수히 발견되었고 호염기성이었으며 크기는 직경 2∼4 ㎛정도 되었다. 이들의 여러 발육 단계에 대해 주사 전자현미경 및 투과 전자현미경으로 입체구조를 관찰하였으며 그 결과 충체의 종은 C. Parvum으로 동정하였다. 항균제(tetracycline, trimethoprim-sulfamethoxazole)를 면역억제제와 함께 투여한 실험군에서도 Cryptosporidium이 발현되었으나 면역 억제제만을 투여한 실험군의 마우스보다 수명을 다소 연장시킬 수 있었다. 이 실험 결과 우리 나라에도 Cryptosporidium(C. Parvum)이 존재하고 있음을 확인하였으며 인체 감염례가 있을 가능성을 짐작할 수 있었다.

• 한국임상수의학회지
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• 제23권3호
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• pp.243-250
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• 2006

The chickens fed with the feeds supplemented with green tea(GT) and lactic acid bacteria(LB) were infected orally with 10,000 oocysts per chicken of E. maxima. The groups administered with the feeds supplemented with GT by 0.5% and 2.0% of feed showed the significant levels of decreasing in the number of oocysts shed for 5 days after E. maxima infection. The feeds supplemented with LB by 0.1% and 0.5% of feed were less effective in reducing the number of the fecal oocyst, compared with the groups administered with GT. To evaluate the immunoregulatory effects of the feed additives, the expression patterns of IL-2 and IFN-r in spleen cells were studied by RT-PCR and ELISA. The higher levels of IL-2 transcripts after E. maxima infection were observed in the groups with n, compared with the groups with LB and the mixture of GT and LB. The $IFN-\gamma$ mRNA bands were observed in the all of experimental groups except the uninfected control. The culture supernatants of Con A-stimulated spleen cells($5{\times}10^6cells/ml$) were measured for the concentration of IL-2 and $IFN-\gamma$ by ELISA. The levels of IL-2 and $IFN-\gamma$ on days 3 and 7 after E. maxima infection were significantly augmented in the groups with n. These results indicated that GT-supplemented feeds resulted in higher reduction of oocyst-shedding and more enhanced immune responses in the chicken infected with E. maxima, as compared with LB-supplemented feeds. According to the results, it was implicative that the supplements could be utilized for development of feed additives for anti-coccidiosis.

• Parasites, Hosts and Diseases
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• 제34권2호
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• pp.113-120
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• 1996

서울 및 전남 지역 주민의 작은와포자충(Cryptosporidium parvum) 감염 상황을 알아보기 위하여 1992년에 표본조사를 실시하였다. 한편, 높은 오시스트 양성률을 보인 전남 화순군 이양면에 대해서는 1995년에 재조사를 시행하였다. 구체적 대상 지역은 서울의 8개 동(동) 및 전라남도 도시지역 4개 동 및 농촌지역 7개 면으로 하였다. 총 3,146명을 무작위로 선정하여 분변을 채취하였고, 포르말린-에텔법으로 침전시킨 다음 침사로부터 도말표본을 1인 1매 제작하였다. 표본을 modified acid fast 법으로 염색한 후 작은와포자충의 오시스트 양성 여부를 조사하였다. 총 오시스트 양성률은 7.9%(248/3. 146)이었으나 서을 0.5%(4/853) 및 전라남도 10.6% (244/2.293)로서 지역별로 큰 차이를 보였다. 오시스트의 크기는 $4.8{\;}{\pm}{\;}0.5{\;}by{\;}4.2{\;}{\pm}{\;}0.5{\;}\mu\textrm{m}$로 C. parvum에 부합되었다. 전라남도의 경우 농촌 지역은 14.0%로 도시 지역의 3.7%보다 유의하게 양성률이 높았다. 특히 대표적인 농촌 지역의 하나인 화순군 이양면의 경우에는 40.0%(74/185)의 매우 높은 양성률을 나타내었다. 절체 조사 대상자에서 볼 때 51-70세 연령군 이 모든 연령군 중 가장 높은 양성률을 보였다. 화순군 이양면에 대한 제2차 조사(1995년)에서는 주민 125명 중 44(35.2%)명이. 소 15두 중 14두(93.3%)가 분변내 오시스트 양성이었다 이상의 결과로 전라남도 농촌 지역이 작은와포자충의 농후 유행지임을 알 수 있었고 중요한 감염원 (감염 방식)으로는 오염된 물이나 감염된 소와의 접촉일 것으로 추정되었다.

• Parasites, Hosts and Diseases
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• 제35권4호
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• pp.245-250
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• 1997

마우스에 있어서 쥐와포자충 감염에 대한 면역기전을 해명하기 위하여 이 원충을 최초 및 도전 감염시켜 위점막 비만세포수의 동태를 관찰하였다. ICR계 SPF3주령 마우스에. 그리고 감염 내과 후 분변 내의 오오시스트 음전 후에 두 번에 걸쳐 각각 $2{\;}{\times}{\;}10^6$의 쥐와포자충 (MCR주) 오오시스트를 경구투여하였다 최초 감염 후 5일 및 도전 감염 후 10일 간격으로 희생시켜 위를 적출하여 pH 2.0으로 조정된 Camoy's solution에 5-6시간 고정한 다음 pH 0.3으로 조정된 l% alcian blue에서 2시간. pH 1.0의 0.5% sihnin에서 5분간 염색하여 위점막 비만세포수를 계수하였다. 위점막 비만세포수는 최초 감염 후 15일에서 25일까지 최고치에 이른 다음 30일에 감소하여 그 이후에는 정상으로 복귀하였으며. 도전 감염 후 20-30일에도 역시 증가하였다 최초 감염 후 이 세포의 증가 후에는 분변에 배설되는 오오시스트의 수도 감소하였으며. 도전 감염 후에는 분변에서 오오시스트를 거의 검출할 수 없었다 이러한 사실로 미루어 보아 이 세포는 최초 감염 흡충체 배출. 그리고 도전 감염의 방어기전과 관련이 있다고 생각한다.

• Parasites, Hosts and Diseases
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• 제60권4호
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• pp.241-246
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• 2022

Felids are the unique definitive host of Toxoplasma gondii. The intestine of felid is the only site for initiating Toxoplasma gondii sexual reproduction. T. gondii excretes millions of infectious oocysts from the intestine, which are the primary source of infection. There are many difficulties in developing vaccines and drugs to control oocyst excretion due to the lack of an appropriate experimental model. Here, we established an in vitro feline intestinal epithelial cell (IEC) infection system and an efficient animal model of T. gondii Chinese 1 genotype, Wh6 strain (TgCtwh6). The Kunming mice brain tissues containing TgCtwh6 cysts were harvested 42-day post-infection. The bradyzoites were co-cultured with cat IECs in vitro at a ratio of 1:10. Five 3-month-old domestic cats were orally inoculated with 600 cysts each. The oocysts were detected by daily observation of cat feces by microscopy and polymerase chain reaction. We found that the parasite adhered and invaded cat IECs in vitro, transformed into tachyzoites, and then divided to form rose-like structures. These parasites eventually destroyed host cells, escaped, and finished the asexual reproduction process. Schizonts associated with sexual reproduction have not been observed during development in vitro cultured cells. However, schizonts were detected in all infected cat intestinal epithelial cells, and oocysts were presented in all cat feces. Our study provides a feasible cell model and an efficient infection system for the following studies of T. gondii sexual reproduction, and also lays a foundation to develop drugs and vaccines for blocking excretion and transmission of oocysts.

• 대한수의학회지
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• 제28권1호
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• pp.169-174
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• 1988

To determine the prevalence and the morphological identification of two Eimeria species in fecal examinations, a total of 1092 fecal specimens collected during the period of March to December in 1987 was tested by means of flotation technique. The results obtained were summarized as follow: 1. The prevalence of two species was revealed as 1.83% and 0.92% in E. bukidnonensis and E. wyomingensis, respectively. 2. The oocysts of E. bukidnonensis measured in range of $41.3{\mu}m$ to $49.4{\mu}m(mean\;45.5{\pm}1.7){\times}28.8{\mu}m$ to $35.3{\mu}m(mean\;32.2{\pm}1.2)$, and E. wyomingensis $36.9{\mu}m$ to $44.5{\mu}m(mean\;39.8{\pm}1.7){\times}26.5{\mu}m$ to $29.9{\mu}m(mean\;28.2{\pm}0.9)$. 3. The oocysts of E. bukidnonensis appeared darker and more robust than those of E. wyomingensis. 4. The striations in the oocyst wall of E. bukidnonensis were more peculiar than in E. wyomingensis. 5. Among the morphological characteristic, the widths could be reliably taken as a differential point of view for two Eimeria species.

• 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.