• Parasites, Hosts and Diseases
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• 제34권1호
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• pp.15-20
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• 1996

이 실아메바(Entamoeba histoIytica)와 동형 아메바(Entamoebc dispar. 동형아메바)의 포낭은 형태학적으로 구분이 안되어 종 감별에 관하여 논란이 있어 왔다. 최근에 이 둘이 별종이며 특히 이질아메바는 병원성이고 동형아메바는 비병윈성입이 확인퇴어 그 감별이 중요한 의미를 갖게 피었나 이 연구에서는 우리 나라의 아메바 분리체를 중합효소 반응과 제한효소 반응을 이용하여 두 종으로 감별하였다. 1994-1995년에 대변을 통강의 방법으로 검색하여 포낭이나 영양형이 발견된 검체를 로빈슨 배지에서 배양하고 배양된 영양형에서 DNA를 분리하였다. PI 유전자 염기서열 중에서 시발페(primer)를 만득어 중합효소 반응으로 482 bp 크기의 산물을 얹고 이를 제한효소(Tuq I, Xmn I, Acc I)로 처리하였다. 또한 Xmn I과 Acc I 제한 효소의 특이 염기서열온 고함하는 시발체를 제작하여 따로 중합효소 반응을 시행하였다. 그 결과 13개 분리체 중에서 S9, S12, YS-6, YS-27의 482 bp 산물은 Taq I과 Xmn I 의하여 그 외의 분리체 산물은 Acc I에 의하여 절단되었다. 이 결과는 특이 염기서열 시발체의 중합효소 반응에서 얻은 산물과 일치하였다, 이 결과에 의하여 분리체 S9, S12, YS-6는 대장염 창자에서. YS-27은 간농양 환자에서 분리한 병원성의 이질아메바(E. histolytica)이고 분리체 S1, S3, S11, S15, S16, S17, S20, YS-17, YS-44는 부증상의 포낭배출자에서 얻은 비병원성의 동형아메바(E. nispur)로 구별할 수 있었다. S1은 설사 환자에서 얻은 분리체 이지탄 동형아메바임을 확인하였고 따라서 이 환자의 설사는 다른 원인에 의한 것으로 판단 된다. 이로써 비병원성인 동형아메바가 우리 나라에서도 병원성 이질아메바보다 더 흔하게 존재한다는 것을 처음으로 기록하며 E. dispar의 우리 말 이름을 동형아메바로 제안한다.

• Parasites, Hosts and Diseases
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• 제51권2호
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• pp.231-236
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• 2013

The present study was conducted to investigate the clinical outcomes of Entamoeba histolytica infection in symptomatic and asymptomatic Orang Asli (aborigine) communities in Malaysia. Examination was performed on 500 stool samples obtained from Orang Asli communities in 3 different states using formalin-ether concentration, trichrome staining, and single-round PCR techniques. Out of 500 stool samples, single infection of E. histolytica, Entamoeba dispar, and Entamoeba moshkovskii was identified in 3.2%, 13.4%, and 1%, respectively. In addition, 10 samples had mixed infections with E. histolytica and E. dispar. Six samples containing E. dispar were also positive for E. moshkovskii, and only 2 samples had E. histolytica in association with E. dispar and E. moshkovskii. Seventeen E. histolytica-positive samples were from symptomatic subjects, whereas the remaining 11 samples came from asymptomatic subjects. These findings suggest a predominant distribution of pathogenic potential of E. histolytica strains in this community. Therefore, further studies on genotyping of E. histolytica is required, to find out association between E. histolytica genotype and the outcome of the infection.

• Parasites, Hosts and Diseases
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• 제51권5호
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• pp.519-524
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• 2013

This study investigated the effect of breast-feeding in protection against protozoan infection in infants with persistent diarrhea. Infants were classified into 2 groups; 161 breast-fed infants and the same number of non-breast-fed infants. Microscopic examinations of stool were done for detection of parasites and measuring the intensity of infection. Moreover, serum levels of IgE and TNF-${\alpha}$ were measured by ELISA. Cryptosporidium spp., Entamoeba histolytica/Entamoeba dispar, Giardia lamblia, and Blastocystis sp. were demonstrated in infants with persistent diarrhea. The percentage of protozoan infections was significantly lower in breast-fed infants than that in the non-breast-fed infants. The levels of IgE and TNF-${\alpha}$ were significantly lower in the breast-fed group than in the non-breast-fed group. There were significant positive associations between the serum levels of IgE and TNF-${\alpha}$ and the intensity of parasite infection in the breast-fed group. It is suggested that breast-feeding has an attenuating effect on the rate and intensity of parasite infection.

• Parasites, Hosts and Diseases
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• 제56권1호
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• pp.33-39
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• 2018

Intestinal parasitic infections remain a major public health problem in many parts of Thailand, particularly in rural areas. This study aimed to determine the prevalence of intestinal parasitic infections and associated risk factors among the people living in Huai Sai sub-district, Bang Khla district, Chachoengsao Province, central Thailand. A cross-sectional survey was carried out from June 2017 to August 2017 which included a total of 224 participants. Stool samples were examined using a simple direct smear and formalin ethyl acetate concentration technique. Association between risk factors and intestinal parasitic infections was assessed using multivariate logistic regression analysis. The overall prevalence of intestinal parasitic infections was 16.1%. Soil-transmitted helminth infections (14.3%) were more common than protozoan infections (1.8%). The most common intestinal parasites were hookworms (6.7%) followed by Strongyloides stercoralis, (5.0%), Ascaris lumbricoides (1.3%) and Trichuris trichiura (1.3%). Entamoeba histolytica/dispar (1.0%), Giardia intestinalis (0.4%), and Blastocystis hominis (0.4%) were the protozoans identified. A high prevalence of infections was found in male participants of ${\geq}40years$ who raised dogs in the households and did not wear boots while working fields. Multivariate analysis showed a significant association of intestinal parasitic infections with gender with the adjusted odds ratio (OR) of 2.4 and 95% confidence interval (CI) of 1.1-5.2 (P=0.020). The results showed a high prevalence of soil-transmitted helminth infections among adults in rural communities which were particularly apparent regarding the skin-penetrating species of nematodes. A greater focus on intervention is required by improving sanitation and personal hygiene to prevent the spread of intestinal parasitic infections.

• Parasites, Hosts and Diseases
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• 제34권4호
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• pp.247-254
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• 1996

임상증상 없이 검변을 통하여 검출된 이질아메바 포낭양성자를 어떻게 다루어야 할지 오랫동안 논란이 있었으나 이중에서 병원성이 강한 이질아메바(E. histolytica)만 치료하고 병원성이 없는 동형아메바(E. dispar)는 치료하지 않는 것으로 의견이 모아져 있다. 따라서 이 두 종을 감별하는 것이 실제적으로 중요하게 되었고 이를 위하여 동위효소 분석 유전자 분석. 혈청학적인 검사가 가능하다. 그러나 앞의 두 분석법은 원충을 배양하여야 가능하기 때문에 적용하기 어려운 경우가 많아 혈청학적인 감별이 실제적으로 유용하다. 이 연구는 우리 나라에서 무균배양에 성공한 이질 아메바 YS-27의 항원성을 확인된 아메바 감염자 혈청과 면역이적법으로 검증하고. 이를 이용하여 무증상 포낭배출자에서 두 종의 감염을 감별하고자 하였다. 시스테인계 단백질분해효소 억제제인 E64를 첨가한 이질아메바의 항원은 117. 110. 99. 68. 66. 60. 54. 52 46. 45 kDa 분획이 이질아메바 감염이 확인된 사람의 혈청내 IgG 항체와 반응하였고 동형아메바 대장아메바 Beastnystis 및 대조군의 혈청과는 117 kDa 분획이 미약하게 반응하였다. 포낭양성자의 혈청내 IgA 항체와 많은 분획이 반응하였으나 두 종 양성자간에 차이가 없었고 혈청내 IgM과 IgE 항체와 반응하는 분획이 없었다. 동형아메바의 항원은 두 종 양성자 혈청내 모든 군의 항체와의 반응에서 두종을 감별하지 못하였다. 따라서 이질아메바의 항원과 혈청내 IgG 항체 반응이 두 아메바 감염 을 감별할 수 있었다. 증상이 없는 포낭배출자 24명의 혈청을 면역이적 반응시킨 결과 2명에서 46 과 45 kDa 분획을 제외한 다른 모든 분획과 반응하여 이질아메바 감염자로 확인하였고 22명은 동 형아메바 양성자로 확인하였다. 이 자료를 토대로 하면 우리 냐라에서 검출되는 단순 포낭배출자 의 90% 이상은 이질아메바가 아니라 동형아메바 감염자이고. 이에 따라서 포낭양성자 중 환자가 많지 않은 사실을 설명할 수 있을 것이다. 이질아베바 조항원을 이용한 면역이적법은 증상이 없는 아메바 포낭배출자 중 치료를 꼭 필요로 하는 사람을 찾아내는 방법으로 유용함을 확인하였다.

• Journal of Microbiology
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• 제41권2호
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• pp.148-151
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• 2003

Waterborne parasite infections are considered a reemerging threat. Most studies on the epidemiology of human cryptosporidiosis, giardiasis, and amebiasis have been carried out in developed countries, and there is little data on the occurrence of these infections in other areas. The objective of this study was to investigate the presence of waterborne parasites such as Cryptosporidium parvum, Giardia lamblia and Entamoeba histolytica in various water samples in Ankara, turkey. A total of 85 samples were examined, 43 from the municipal water supply, 34 from wells, 6 from the Ankara River, and 2 from two untreated dams; by conventional microscopy, immunologically and by polymerase chain reaction (PCR). Oocysts of C. parvum and cysts of G. lamblia were detected by using an indirect fluorescence (antigen) assay, whereas an enzyme linked immunosorbent assay was used to detect the cysts of E. histolytica and E. dispar. In addition, PCR was used for E. histolytica, E. dispar, C. parvum and G. lamblia detection. G. lamblia was found in 2 of the 34 well water samples, and parasites were found in 3 of the 6 Ankara River samples. The 1$\^$st/ contained E. histolytica cysts and Strongyloides stercoralis larvae. the 2$\^$nd/ E. histolytica cysts, and Trichuris trichiura eggs, and the 3$\^$rd/ C. parvum oocysts only. No parasite was observed in the municipal water samples and untreated dam water samples. These results extend our knowledge on waterborne parasites, such occurrence information on waterborne pathogens assists the management and treatment of municipal water.

• Parasites, Hosts and Diseases
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• 제52권2호
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• pp.215-220
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• 2014

We analyzed 320 clinical samples of parasitic infections submitted to the Department of Environmental Biology and Medical Parasitology, Hanyang University from January 2004 to June 2011. They consisted of 211 nematode infections, 64 trematode or cestode infections, 32 protozoan infections, and 13 infections with arthropods. The nematode infections included 67 cases of trichuriasis, 62 of anisakiasis (Anisakis sp. and Pseudoterranova decipiens), 40 of enterobiasis, and 24 of ascariasis, as well as other infections including strongyloidiasis, thelaziasis, loiasis, and hookworm infecions. Among the cestode or trematode infections, we observed 27 cases of diphyllobothriasis, 14 of sparganosis, 9 of clonorchiasis, and 5 of paragonimiasis together with a few cases of taeniasis saginata, cysticercosis cellulosae, hymenolepiasis, and echinostomiasis. The protozoan infections included 14 cases of malaria, 4 of cryptosporidiosis, and 3 of trichomoniasis, in addition to infections with Entamoeba histolytica, Entamoeba dispar, Entamoeba coli, Endolimax nana, Giardia lamblia, and Toxoplasma gondii. Among the arthropods, we detected 6 cases of Ixodes sp., 5 of Phthirus pubis, 1 of Sarcoptes scabiei, and 1 of fly larva. The results revealed that trichuriasis, anisakiasis, enterobiasis, and diphyllobothriasis were the most frequently found parasitosis among the clinical samples.

• Parasites, Hosts and Diseases
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• 제35권3호
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• pp.203-210
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• 1997

이질아메바 병원성 분리주에서 특이적으로 발현되는 mRNA를 동정하고자 differential display reverse transcription-polymerase chain reaction(DDRT-PCR)을 수행하여 병원성 특이 증폭산물을 확인하였다. 한국인에서 검출한 이질아메바 병원성 분리주 YS-27과 Entamoeba dispar분리주인 S 16으로부터 정제한 mRAN를 주형으로 11개의 arbitrary primer와 3개의 one base anchored $oligo-dT_{11}M$(M: A, C 또는 G)의 조합을 이용, DDRT-PCR을 실시한 결과 31개의 분획이 YS-27주에서만 증폭된 것으로 확인되었다. 이 331개 DNA 중 21개는 cysteine proteinase 유전자와 상동성을 나타내었다. YS-27주로부터 제작된 cDNA library를 나머지 DNA를 탐침으로 사용, 검색하여 최종 4개의 clone을 얻었다. 이 4개의 clone을 이용, immunoscreening을 수행한 결과, 이 clone들은 이질아메바 감염자 혈청과 양성반응을 나타내고 있었다.

• Parasites, Hosts and Diseases
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• 제55권5호
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• pp.523-532
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• 2017

A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor.