関: E. histolytica、Entamoeba histolytica

WordNet

penetrate or assault, in a harmful or injurious way; "The cancer had invaded her lungs"
march aggressively into anothers territory by military force for the purposes of conquest and occupation; "Hitler invaded Poland on September 1, 1939" (同)occupy
occupy in large numbers or live on a host; "the Kudzu plant infests much of the South and is spreading to the North" (同)overrun, infest

PrepTutorEJDIC

〈敵が〉…‘に'『侵入する』 / 〈人が〉…‘に'『押し寄せる』 / 〈権利など〉‘を'『侵害する』(violate) / 〈病気などが〉…‘を'おかす

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/04/13 19:22:04」(JST)

wiki en

Entamoeba invadens is a protozoan parasite of reptiles, within the genus Entamoeba. It is closely related to the human parasite Entamoeba histolytica, causing similar invasive disease in reptiles,^[1] in addition to a similar morphology and lifecycle.^[2]

Disease and lifecycle

E. invadens is a causative agent of amoebiasis in reptiles, such as snakes and lizards. Reptile amoebiasis can be treated with metronidazole, an amoebicide drug.^[3]

E. invadens is primarily transmitted via the ingestion of contaminated faeces, also known as the faecal-oral route. It has two distinct lifecycle stages. The first is a resistant cyst stage, which is transmitted outside of a host, and is also known as the infectious stage. The second is the motile trophozoite stage, which is released from the cyst following introduction into the host environment, and is the disease-causing (pathogenic) stage.^[3]

While there is no specialised intermediate vector stage, contaminated faeces can be transmitted to food sources by some arthropods (e.g. flies and cockroaches), where E. invadens may be ingested. Symptomless carriers of E. invadens, such as crocodilians, may act as a reservoir of infection, particularly in captivity.^[3]

Use in research

E. invadens has been used as a model system for studying development, and encystation in vitro, particularly due to difficulties associated with studying encystation in the closely related human parasite E. histolytica.^[1]

Genome

The genome of E. invadens, sequenced in 2013, was approximately 40 MB in size, and predicted to contain 11,549 genes. Overall, the genome was considered to be highly repetitive. Many genes occurred in large, multi-gene families.^[1]

References

^ ^a ^b ^c Ehrenkaufer et al. (26 July 2013). "The genome and transcriptome of the enteric parasite Entamoeba invadens, a model for encystation". Genome Biology 14. doi:10.1186/gb-2013-14-7-r77. Retrieved 19 December 2014.
^ Sanchez et al. (September 1994). "Identification of a developmentally regulated transcript expressed during encystation of Entamoeba invadens". Molecular and Biochemical Parasitology 67. doi:10.1016/0166-6851(94)90102-3. Retrieved 22 December 2014.
^ ^a ^b ^c Chia et al. (July 2009). "Entamoeba invadens Myositis in a Common Water Monitor Lizard (Varanus salvator)". Veterinary Pathology 46. doi:10.1354/vp.08-VP-0224-P-CR. Retrieved 22 December 2014.

External links

Genbank Genome Sequencing Data

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 非病原性腸内原虫 nonpathogenic enteric protozoa
2. 赤痢アメーバによる腸菅アメーバ症 intestinal entamoeba histolytica amebiasis
3. 赤痢アメーバによる腸菅外アメーバ症 extraintestinal entamoeba histolytica amebiasis
4. 先進国における急性下痢の疫学および原因 epidemiology and causes of acute diarrhea in developed countries
5. 脳膿瘍の病因、臨床症状、および診断 pathogenesis clinical manifestations and diagnosis of brain abscess

English Journal

Molecular epidemiology and genetic diversity of Entamoeba species in a chelonian collection.

García G1, Ramos F, Pérez RG, Yañez J, Estrada MS, Mendoza LH, Martinez-Hernandez F, Gaytán P.Author information 1Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Av. Universidad 3000, Colonia Copilco Universidad, Delegación Coyoacan, México DF, CP 04510, México.AbstractVeterinary medicine has focused recently on reptiles, due to the existence of captive collections in zoos and an increase in the acquisition of reptiles as pets. The protozoan parasite, Entamoeba can cause amoebiasis in various animal species and humans. Although amoebiasis disease is remarkably rare in most species of chelonians and crocodiles, these species may serve as Entamoeba species carriers that transmit parasites to susceptible reptile species, such as snakes and lizards, which can become sick and die. In this study, we identified the Entamoeba species in a population of healthy (disease-free) chelonians, and evaluated their diversity through the amplification and sequencing of a small subunit rDNA region. Using this procedure, three Entamoeba species were identified: Entamoeba invadens in 4.76 % of chelonians, Entamoeba moshkovskii in 3.96 % and Entamoeba terrapinae in 50 %. We did not detect mixed Entamoeba infections. Comparative analysis of the amplified region allowed us to determine the intra-species variations. The E. invadens and E. moshkovskii strains isolated in this study did not exhibit marked differences with respect to the sequences reported in GenBank. The analysis of the E. terrapinae isolates revealed three different subgroups (A, B and C). Although subgroups A and C were very similar, subgroup B showed a relatively marked difference with respect to subgroups A and C (Fst = 0.984 and Fst = 1.000, respectively; 10-14 % nucleotide variation, as determined by blast) and with respect to the sequences reported in GenBank. These results suggested that E. terrapinae subgroup B may be either in a process of speciation or belong to a different lineage. However, additional research is necessary to support this statement conclusively.
Journal of medical microbiology.J Med Microbiol.2014 Feb;63(Pt 2):271-83. doi: 10.1099/jmm.0.061820-0. Epub 2013 Nov 5.
Veterinary medicine has focused recently on reptiles, due to the existence of captive collections in zoos and an increase in the acquisition of reptiles as pets. The protozoan parasite, Entamoeba can cause amoebiasis in various animal species and humans. Although amoebiasis disease is remarkably rar
PMID 24194557

Strategies to discover the structural components of cyst and oocyst walls.

Samuelson J1, Bushkin GG, Chatterjee A, Robbins PW.Author information 1Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, USA.AbstractCysts of Giardia lamblia and Entamoeba histolytica and oocysts of Toxoplasma gondii and Cryptosporidium parvum are the infectious and sometimes diagnostic forms of these parasites. To discover the structural components of cyst and oocyst walls, we have developed strategies based upon a few simple assumptions. Briefly, the most abundant wall proteins are identified by monoclonal antibodies or mass spectrometry. Structural components include a sugar polysaccharide (chitin for Entamoeba, β-1,3-linked glucose for Toxoplasma, and β-1,3-linked GalNAc for Giardia) and/or acid-fast lipids (Toxoplasma and Cryptosporidium). Because Entamoeba cysts and Toxoplasma oocysts are difficult to obtain, studies of walls of nonhuman pathogens (E. invadens and Eimeria, respectively) accelerate discovery. Biochemical methods to dissect fungal walls work well for cyst and oocyst walls, although the results are often unexpected. For example, echinocandins, which inhibit glucan synthases and kill fungi, arrest the development of oocyst walls and block their release into the intestinal lumen. Candida walls are coated with mannans, while Entamoeba cysts are coated in a dextran-like glucose polymer. Models for cyst and oocyst walls derive from their structural components and organization within the wall. Cyst walls are composed of chitin fibrils and lectins that bind chitin (Entamoeba) or fibrils of the β-1,3-GalNAc polymer and lectins that bind the polymer (Giardia). Oocyst walls of Toxoplasma have two distinct layers that resemble those of fungi (β-1,3-glucan in the inner layer) or mycobacteria (acid-fast lipids in the outer layer). Oocyst walls of Cryptosporidium have a rigid bilayer of acid-fast lipids and inner layer of oocyst wall proteins.
Eukaryotic cell.Eukaryot Cell.2013 Dec;12(12):1578-87. doi: 10.1128/EC.00213-13. Epub 2013 Oct 4.
Cysts of Giardia lamblia and Entamoeba histolytica and oocysts of Toxoplasma gondii and Cryptosporidium parvum are the infectious and sometimes diagnostic forms of these parasites. To discover the structural components of cyst and oocyst walls, we have developed strategies based upon a few simple as
PMID 24096907

The ribosomal RNA transcription unit of Entamoeba invadens: Accumulation of unprocessed pre-rRNA and a long non coding RNA during encystation.

Ojha S1, Singh N2, Bhattacharya A3, Bhattacharya S4.Author information 1School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India. Electronic address: sandy.mbt@gmail.com.2School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India. Electronic address: nishant900@gmail.com.3School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India. Electronic address: alok.bhattacharya@gmail.com.4School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India. Electronic address: sbjnu110@gmail.com.AbstractThe ribosomal RNA genes in Entamoeba spp. are located on extrachromosomal circular molecules. Unlike model organisms where rRNA transcription stops during growth stress, Entamoeba histolytica continues transcription; but unprocessed pre-rRNA accumulates during stress, along with a novel class of circular transcripts from the 5'-external transcribed spacer (ETS). To determine the fate of rRNA transcription during stage conversion between trophozoite to cyst we analyzed Entamoeba invadens, a model system for differentiation studies in Entamoeba. We characterized the complete rDNA transcription unit by mapping the ends of pre-rRNA and mature rRNAs. The 3' end of mature 28S rRNA was located 321nt downstream of the end predicted by sequence homology with E. histolytica. The major processing sites were mapped in external and internal transcribed spacers. The promoter located within 146nt upstream of 5' ETS was used to transcribe the pre-rRNA. On the other hand, a second promoter located at the 3' end of 28S rDNA was used to transcribe almost the entire intergenic spacer into a long non coding (nc) RNA (>10kb). Interestingly we found that the levels of pre-rRNA and long ncRNA, measured by northern hybridization, decreased initially in cells shifted to encystation medium, after which they began to increase and reached high levels by 72h when mature cysts were formed. Unlike E. histolytica, no circular transcripts were found in E. invadens. E. histolytica and E. invadens express fundamentally different ncRNAs from the rDNA locus, which may reflect their adaptation to different hosts (human and reptiles, respectively). This is the first description of rDNA organization and transcription in E. invadens, and provides the framework for further studies on regulation of rRNA synthesis during cyst formation.
Molecular and biochemical parasitology.Mol Biochem Parasitol.2013 Nov-Dec;192(1-2):30-8. doi: 10.1016/j.molbiopara.2013.10.002. Epub 2013 Nov 5.
The ribosomal RNA genes in Entamoeba spp. are located on extrachromosomal circular molecules. Unlike model organisms where rRNA transcription stops during growth stress, Entamoeba histolytica continues transcription; but unprocessed pre-rRNA accumulates during stress, along with a novel class of cir
PMID 24200639

Japanese Journal

ボールニシキヘビPython reginus4例にみられた爬虫類アメーバ症(短報)(病理学)

柑本敦子,内田和幸,堀井洋一郎,奥村純代,山口良二,立山晉
The journal of veterinary medical science 63(12), 1365-1368, 2001-12-25
… て死亡した.剖検では, 全例に重度の出血性大腸炎が認められた.組織学的には, 全例で重度のアメーバ様原虫をともなう壊死性出血性大腸炎が認められた.原虫はマクロファージ様形状, あるい肥厚した細胞壁を有する原虫シストの形態を示していた.これらの原虫は大腸壁全層に分布していた.以上の所見より, アメーバ原虫感染症, 特に爬虫類アメーバ症に最も代表的なEntamoeba invadensの感染が疑われた. …
NAID 110003920808

P85 Entamoeba invadens の増殖、シスト形成および細胞骨格に及ぼすアクチン重合促進・安定化剤 Jasplakinolide の効果

牧岡朝夫,熊谷正広,大友弘士,小林正規,竹内勤
衞生動物 52(Supplement), 99, 2001-04-04
NAID 110003822123

Related Pictures

★リンクテーブル★

リンク元	「E. histolytica」
関連記事	「invade」「Entamoeba」

「E. histolytica」

Entamoeba invadens
Scientific classification
Domain:	Eukaryota
Phylum:	Amoebozoa
Class:	Archamoebae
Order:	Amoebida
Genus:	Entamoeba
Species:	E. invadens
Binomial name
	Entamoeba invadens;