• Parasites, Hosts and Diseases
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• 제54권4호
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• pp.439-446
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• 2016

Toxoplasmosis is a protozoan disease that is caused by Toxoplasma gondii in livestock and humans. Due to its medical and veterinary importance, it is essential to study the seroprevalence of T. gondii infection among humans and animals in various parts of the world. The major objective of this study was to determine the seroprevalence and spatial distribution of toxoplasmosis in small ruminants (sheep and goats) of north-eastern region, Pakistan. A total of 1,000 animals comprising of sheep (n=470) and goats (n=530) were examined for T. gondii infection by using ELISA. An epidemiological data was collected in the form of questionnaire. A surface has been generated by using method of interpolation in Arc GIS with the help of IDW (inverse distance weight). The results showed higher seroprevalence of T. gondii in goats (42.8%) as compared to sheep (26.2%). The seroprevalence was higher in females as compared to males in all examined ruminants. Similarly, there is a wide variation in the seroprevalence of T. gondii in different breeds of sheep and goats showing higher seroprevalence in Teddy (52.8%) and Damani breed (34.5%) of goat and sheep's, respectively. The geographical and spatial distribution of T. gondii shows that it is widely distributed in different parts of the north-eastern region of Pakistan. Our results suggest widespread environmental contamination with T. gondii oocysts and that small ruminants could be a potentially important source of T. gondii infection if their infected meat is consumed undercooked.

• Parasites, Hosts and Diseases
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• 제51권2호
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• pp.147-154
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• 2013

To control coccidiosis without using prophylactic medications, a DNA vaccine targeting the gametophyte antigen Gam56 from Eimeria maxima in chickens was constructed, and the immunogenicity and protective effects were evaluated. The ORF of Gam56 gene was cloned into an eukaryotic expression vector pcDNA3.1(zeo)+. Expression of Gam56 protein in COS-7 cells transfected with recombinant plasmid pcDNA-Gam56 was confirmed by indirect immunofluorescence assay. The DNA vaccine was injected intramuscularly to yellow feathered broilers of 1-week old at 3 dosages (25, 50, and $100{\mu}g/chick$). Injection was repeated once 1 week later. One week after the second injection, birds were challenged orally with $5{\times}10^4$ sporulated oocysts of E. maxima, then weighed and killed at day 8 post challenge. Blood samples were collected and examined for specific peripheral blood lymphocyte proliferation activity and serum antibody levels. Compared with control groups, the administration of pcDNA-Gam56 vaccine markedly increased the lymphocyte proliferation activity (P<0.05) at day 7 and 14 after the first immunization. The level of lymphocyte proliferation started to decrease on day 21 after the first immunization. A similar trend was seen in specific antibody levels. Among the 3 pcDNA-Gam56 immunized groups, the median dosage group displayed the highest lymphocyte proliferation and antibody levels (P<0.05). The median dosage group had the greatest relative body weight gain (89.7%), and the greatest oocyst shedding reduction (53.7%). These results indicate that median dosage of DNA vaccine had good immunogenicity and immune protection effects, and may be used in field applications for coccidiosis control.

• Parasites, Hosts and Diseases
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• 제36권4호
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• pp.281-284
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• 1998

닭와포자충에 감염된 닭에서 다른 병원체의 이차 침입에 대한 면역억제능을 입증하기 위하여 2일령 SPF 병아리에 $2{\times}10^6$의 닭와포자충 난포낭을 한 번에 경구투여한 다음 14일 후에 $1{\times}10^9$의 Brucella abortus strain 1119-3 부유액 0.3 ml를 근육주사하였다. 그 다음 3-6일 간격으로 36일간에 걸쳐 채혈한 후 평판응집반응으로 이 세균에 대한 면역반응을 관찰하였다. 전반적으로 감염군과 비감염군 모두 3일 후까지는 이 세균에 대한 혈청응집반응이 전혀 일어나지 않았으나 그 후 혈청응집역가는 비감염군에 비하여 감염군이 의의있게 낮았다 (P＜0.05). 세균 접종 15일 후 감염군과 비감염군에 있어서 최고 역가는 매우 의의있는 차이를 보였다 (P=0.0001). 한편, 진정대조군은 전 실험기간을 통하여 이 세균에 대한 혈청응집반응을 보이지 않았다. 이 연구결과 닭와포자충에 감염된 닭에서 미생물의 침입에 대한 면역반응이 억제됨을 확인하였다.

• 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.

• 대한수의학회지
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• 제35권2호
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• pp.317-326
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• 1995

The purpose of this study was to establish a method for in vitro culture of C parvum isolated in Korea by determination of suitable cell model to complete development of this parasite. The result obtained were summerized as follows: 1. To determine the most suitable cell line, six types of cell line were examined by microscopy. All cell lines were infected with C parvum and showed the highest infection score in HmLu cells. 2. The staining methods including DMSO-modified acid-fast(A-F) stain, hematoxylin-eosin(H & E) stain and immunofluorescence antibody(IFA) stain were applied to examine the infection of C parvum in cell culture. These staining methods were possible to examine the infection of C parvum in cell culture. The most sensitive one was IFA staining technique. 3. Developmental stages of C parvum in HmLu cell were observed. After the initial 8 hour incubation period, some trophozoites were observed. The meronts and gametes were appeared at 24-48 hour post inoculation(PI), and oocysts were observed firstly at 48-72 hour PI. 4. In H & E stain, the parasite appeared as basophilic within parasitophorous vacuole membrane(PVM) and lying in cytoplasm at near the nucleus of the host cells. It was able to distinguish the type I, type II meronts and gametes. 5. In DMSO-modified acid-fast stain, specific stained parasites were appeared firstly after 48 hour PI. The parasites were showed with different degrees of staining bright red color within PVM. 6. The endogenous stages of parasites in HmLu cell recovered at 48, 96, 120 and 144 hour after inoculation were reacted with rabbit immunized serum in immunofluorescence antibody and avidin-biotin complex peroxidase staining technique.

• Parasites, Hosts and Diseases
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• 제36권2호
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• pp.121-126
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• 1998

닭와포자충 감염이 다른 병원체에 대한 닭의 체액성 면역에 미치는 영향을 규명하기 위한 연구의 일환으로 2일령 SPF 병아리에 $5{\;}{\times}10^5$의 닭와포자충 오오시스트를 한 번에 경구투여한 다음 4일과 21일 두 번에 걸척 뉴캣슬병 불활화 (사독) 백신을 접종하였다. 오오시스트 접종 후 2주부터 1주 간격으로 13주까지 채혈하여 혈구응집억제반응으로 ND HI $log_2$ 역가를 경시적으로 측정하여 대조군과 비교, 검토하였다. 일반적으로 뉴캣슬병 바이러스에 대한 Hl가는 전 실험기간을 통하여 대조군에 비하여 실험군이 상당히 낮았으며 (p<0.01), 보다 빨리 음전하는 경향이었다. 백신의 보강주사 후 역가는 점점 높아져서 2주 ($5.00(\;}{\pm}{\;}0$; 비감염 대조군)와 4주 ($3.88{\;}{\pm}{\;}0.6658$; 감염 실험군)에 최고치에 이른 다음 점점 낮아졌다. 한편, 분변 내의 오오시스트 배설 양상은 통상적인 감염례와 같았다. 이로 미루어 보아 병아리가 닭와포자충에 감염되면 건강한 병아리에 비하여 뉴캣슬병 바이러스에 대한 면역억제 현상이 일어나 감수성이 증가할 수 있을 것으로 생각된다.

• Parasites, Hosts and Diseases
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• 제35권3호
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• pp.181-188
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• 1997

닭에 있어서 닭와포자충 갉염이 면역반응에 미치는 영향을 규명하기 위한 기초적 연구리 일환으로 파브리시우스낭의 병리조직학적 소견을 경시적으로 조사하고자 150마리의 2일령 SPF 병아리 (Drkalb-Warren, Sex-Sal-Link)에 닭와포자충의 오오시스트 $5{\;}{\times}{\;}10^5$를 한 번에 경구투여하였타. 분변 속의 오오시스트 배설양상은 정상적이었으며. 파브리시우스낭 지수는 전 실험기간에 걸쳐 거의 변동이 없얹다 많은 수의 원충체가 접종 후 4-16일에 이 낭상피의 미세융또 가장자리에서 관찰되었으며 많은 수의 비만세포가 출현한 다음 원충체가 급격하게 소실하염다. 원충체의 분포상황과 상피 및 인접점막 고유층의 위호산구 침윤은 일치하였다. 이 병소는 상피. 인접 점막고유층의 위호산구 침율과 점만상피 증식을 동반한 미만성 만성 표재성 화농성 파브리시우스낭영의 병리조직학적 소견이었다 이러한 파브리시우스낭염은 면역억제를 유발할 건으로 생각된다.

• Parasites, Hosts and Diseases
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• 제42권1호
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• pp.27-34
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• 2004

We investigated the optimal culture conditions for Cryptosporidium muris in a human stomach adenocarcinoma (AGS) cell line by determining the effects of medium pH and of selected supplements on the development of C. muris. The optimum pH of the culture medium required for the development of C. muris was determined to be 6.6. The number of parasites significantly increased during cultivation for 72 hr (p < 0.05) at this level. On the other hand, numbers decreased linearly after 24 hr of incubation at pH 7.5. When cultured in different concentrations of serum, C. muris in media containing 5% FBS induced 4-7 times more parasites than in 1% or 10% serum. Of the six medium supplements examined, only 1 mM pyruvate enhanced the number of C. muris in vitro. Transmission electron microscopic observation showed the developmental stages of C. muris in the cytoplasm of the cells, not in an extracytoplasmic location. The growth of C. muris in AGS cells provides a means of investigating its biological characteristics and of testing its response to therapeutic agents. However, a more optimized culture system is needed for the recovery of oocysts on a large scale in vitro.

• Parasites, Hosts and Diseases
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• 제47권2호
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• pp.131-138
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• 2009

The present study surveyed the prevalence of natural infection of the sheep esphagus muscle with sarcocysts of Sarcocystis ovicanis and examined induction of protective immunity using UV-attenuated sporocysts. The overall prevalence of natural infection of the sheep was 95%. Infectivity of the collected sarcocysts was confirmed by shedding of sporulated oocysts after feeding infected esophageal tissues to dogs. To induce protective immunity, lambs were immunized 3 times (once a week) with $1.5{\times}10^4$ sporocysts exposed to UV-light for 30min (UV-30 group) or 60 (UV-60 group) min and then challenged with $1.5{\times}10^4$ normal sporocysts at the 3rd week post the 1st vaccination. These lambs showed high survival and less clinical signs of sarcocystosis than normal infected lambs. The attenuated sporocysts produced abnormal cysts; small in size and detached from the muscle fiber. These abnormalities were more obvious in UV-60 group than UV-30 group. Also, the $IFN-{\gamma}$ level and lymphocyte percentage were increased while the total leukocyte count was decreased in the UV-60 group compared with other groups. The high level of $IFN-{\gamma}$ may be an evidence for the induction of Th1 responses which may have protective effect against a challenge infection.

• 대한수의학회지
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• 제33권3호
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• pp.471-478
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• 1993

Culicoides arakawae is a kind of the main blood sucking insects of domestic fowls and serves as a vector of Leukocytozoom caulleryi, the causative protozoon of chicken leukocytozoonosis. In this study, the complete life history of C arakawae was cycled by laboratory colonization. Adult midges were collected from various poultry farm by light trap. The laboratory colonization was performed under the conditions of constant temperature of $25{\pm}1^{\circ}C$ and relative humidity of 80% or above. The hatched larvae were cultured in larval medium consisted of rice field mud and activated charcoal powder. The surface of medium was continuously flowed with biologically conditioned water. The fine powder meal composed of pellet feed for mice and equal mount of yeast was supplied for feeding larvae at every 72 hours. The life cycle completed at $25^{\circ}C$ in 35~35 days ; the period of preoviposition, egg. larval and pupal stage was 2~3, 3~4, 28~30 and 3 days, respectively. The measurements of the eggs, the lst instar larvae, the 4th instar larvae and pupae was $36.28{\mu}m{\pm}1.95$, $13.58{\mu}m{\pm}0.72$, $4000{\mu}m{\pm}1.47$ and $219.95{\mu}m{\pm}6.25$ in $mean{\pm}S.D.$, respectively. In order to confirm experimental colonization of C arakawae in laboratory, the colonized adult midges were allowed to suck blood from chicken infected with L caulleryi. The oocysts and sporozoites could be identified in midguts and salivary grands of engorged midges at 72 hours after blood sucking.