Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/12/24 04:41:40」(JST)

wiki en

Cryptosporidium parvum is one of several protozoal species that cause cryptosporidiosis, a parasitic disease of the mammalian intestinal tract.

Primary symptoms of C. parvum infection are acute, watery, and non-bloody diarrhea. C. parvum infection is of particular concern in immunocompromised patients, where diarrhea can reach 10–15L per day. Other symptoms may include anorexia, nausea/vomiting and abdominal pain. Extra-intestinal sites include the lung, liver and gall bladder where it causes respiratory cryptosporidosis, hepatitis and cholecystitis.^[1]^{[not in citation given]}

Infection is caused by ingestion of sporulated oocysts transmitted by the faecal-oral route. In healthy human hosts, the median infective dose is 132 oocysts.^[2] The general C. parvum life cycle is shared by other members of the genus. Invasion of the apical tip of ileal enterocytes by sporozoites and merozoites causes pathology seen in the disease.

Infection is generally self-limiting in immunocompetent people. In immunocompromised patients, such as those with AIDS or those undergoing immunosuppressive therapy, infection may not be self-limiting, leading to dehydration and, in severe cases, death.

Detection

Cryptosporidium parvum oocysts are very difficult to detect and therefore diagnose. The oocysts in fecal samples would indicate if the parasite is present in the body but they have a very small size and so detection is made very difficult. Doing a fecal ELISA method to detect the presence of the parasite would eliminate the difficulty due to the small size and many other methods are unable to distinguish between past and present infections; something serological ELISA would not allow to distinguish.^[3]

C. parvum is considered to be the most important waterborne pathogen in developed countries. The protozoa also caused the largest waterborne-disease outbreak ever documented in the United States, making 403,000 people ill in Milwaukee, Wisconsin in 1993.^[4] It is resistant to all practical levels of chlorination, surviving for 24hrs at 1000 mg/L free chlorine. It is an obligate intracellular pathogen.^[5]

Prevention

The most effective way to prevent the spread of Cryptosporidium parvum is to avoid the contact of feces that are contaminated. Avoiding this contact, especially with young children is important, as they are more likely to come into oral contact and have the parasite transferred into the body. These ideas of hygiene are the most effective way to combat this difficult to prevent parasite.^[6]

Oocyst Stage

The Cryptosporidium parvum oocysts are incredibly durable and this can cause extended problems when attempting to control the spread of the parasite. The oocyst stage can tolerate a vast number of environmental pressures that allows it to be more likely to survive. The oocyst can tolerate temperatures as low as -22C and for long periods of time which means fecal contamination is possible even after going through those environmental extremes. The oocysts can also tolerate shifts in pH that are found in some water treatment process and careful attention to detail must be done to prevent the possibility of infection. The oocysts that are in fecal material are immediately infective and have the potential to find a new host if contamination occurs.^[3]^[6]

Genome

The genome of C. parvum (sequenced in 2004^[7]) have a relatively small size and simple organization of 9.1 Mb, which is composed of eight chromosomes ranging from 1.04 to 1.5 Mb. The genome is very compact, and is one of the few organisms without transposable elements. Unlike other apicomplexans, C. parvum has no genes in its plastids or mitochondria.^[7]

Treatment

Supportive therapy such as IV fluids is the primary for C. parvum infection. Paromomycin and Nitazoxanide may alleviate some of the diarrhoeal symptoms, however the latter is contraindicated for AIDS patients. Continuing antiretroviral drugs to boost the immune system may also control infection. Research into other potential drugs and therapeutics targets, as well as vaccine candidates, is ongoing. Spiramycin for immunosuppressed patients.

Important C. parvum proteins and drug targets

Lipid metabolism

C. parvum is incapable of de novo lipid synthesis, making its lipid trafficking machinery an important potential therapeutic target. C. parvum possesses multiple oxysterol-binding proteins (OSBPs), and oxysterol related proteins (OSRPs). Only OSBPs are capable of lipid binding, while both contain Pleckstrin homology domains, which function in cell signalling pathways.

Surface glycoproteins

C. parvum possesses numerous surface glycoproteins thought to play a role in pathogenesis. An immunodominant >900kDa protein, known as GP900, localizes to the apical end of sporozoites and in micronemes of merozoites. Its high molecular mass is most likely due to heavy post-translational glycosylation. Indeed, the structure of GP900 is similar to that of a family of glycoproteins known as mucins. GP900 is thought to mediate attachment and invasion to host cells. GP900 may also play a role in C. parvum’s resistance to proteolysis by the numerous proteases found in the mammalian gut.

In vitro, hyperimmune sera as well as antibodies directed at specific epitopes on the GP900 protein inhibit the invasion of C. parvum sporozoites into MDCK cell monolayers. Additionally, competitive inhibition using native GP900 or purified GP900 fragments reduces cell invasion.^[8]

Further experiments have confirmed the importance of the mucin-like glycosylations. Lectins directed at GP900 carbohydrate moieties (alpha-N-galactosamine) were able to block adhesion and prevent C. parvum invasion.^[9]

C. parvum glycoproteins have the characteristics of attractive vaccine candidates. Many are immunodominant, and antibodies against select domains block invasion of host cells.

References

^ ”Cryptosporidiosis.” Laboratory Identification of Parasites of Public Health Concern. CDC. 5 Sept 2007. <http://www.dpd.cdc.gov/dpdx/HTML/Cryptosporidiosis.htm>
^ DuPont HL, Chappell CL, Sterling CR, Okhuysen PC, Rose JB, Jakubowski W (March 1995). "The infectivity of Cryptosporidium parvum in healthy volunteers". N. Engl. J. Med. 332 (13): 855–9. doi:10.1056/NEJM199503303321304. PMID 7870140.
^ ^a ^b DuPont et al "The Infectivivty of Cryptosporidium parvum in healthy Volunteers" http://www.nejm.org/doi/pdf/10.1056/NEJM199503303321304
^ ”Surveillance for Waterborne-Disease Outbreaks -- United States, 1993-1994” CDC. 1996. <http://www.cdc.gov/mmwr/preview/mmwrhtml/00040818.htm>
^ Deng, M.; Lancto, C. A.; Abrahamsen, M. S. (2004). "Cryptosporidium parvum regulation of human epithelial cell gene expression". International Journal for Parasitology 34 (1): 73–82. doi:10.1016/j.ijpara.2003.10.001. PMID 14711592.
^ ^a ^b Robertson et al "Survival of Cryposporidium parvum oocysts under various environmental pressures" http://aem.asm.org/content/58/11/3494.full.pdf+html
^ ^a ^b Abrahamsen MS, Templeton TJ; et al. (2004). "Complete genome sequence of the apicomplexan, Cryptosporidium parvum". Science 304 (5669): 441–5. doi:10.1126/science.1094786. PMID 15044751. Retrieved 2008-05-25. (subscription required)
^ Barnes DA, Bonnin A, Huang JX; et al. (October 1998). "A novel multi-domain mucin-like glycoprotein of Cryptosporidium parvum mediates invasion". Mol. Biochem. Parasitol. 96 (1–2): 93–110. doi:10.1016/S0166-6851(98)00119-4. PMID 9851610.
^ Cevallos AM, Bhat N, Verdon R; et al. (September 2000). "Mediation of Cryptosporidium parvum Infection In Vitro by Mucin-Like Glycoproteins Defined by a Neutralizing Monoclonal Antibody". Infect. Immun. 68 (9): 5167–75. doi:10.1128/IAI.68.9.5167-5175.2000. PMC 101770. PMID 10948140.

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. クリプトスポリジウム症の治療および予防 treatment and prevention of cryptosporidiosis
2. クリプトスポリジウム症の疫学、臨床症状、および診断 epidemiology clinical manifestations and diagnosis of cryptosporidiosis
3. イソスポーラ感染患者の臨床的マネージメント clinical management of patients with cystoisospora infection
4. 急性期および早期のHIV感染：臨床症状および診断 acute and early hiv infection clinical manifestations and diagnosis
5. 高IgM症候群 hyperimmunoglobulin m syndromes

English Journal

Selective and Potent Urea Inhibitors of Cryptosporidium parvum Inosine 5'-Monophosphate Dehydrogenase.

Gorla SK, Kavitha M, Zhang M, Liu X, Sharling L, Gollapalli DR, Striepen B, Hedstrom L, Cuny GD.SourceDepartments of Biology and ∥Chemistry, Brandeis University , 415 South Street, Waltham, Massachusetts 02454, United States.
Journal of medicinal chemistry.J Med Chem.2012 Sep 5. [Epub ahead of print]
Cryptosporidium parvum and related species are zoonotic intracellular parasites of the intestine. Cryptosporidium is a leading cause of diarrhea in small children around the world. Infection can cause severe pathology in children and immunocompromised patients. This waterborne parasite is resista
PMID 22950983

Deposition of Cryptosporidium parvum Oocysts in Porous Media: A Synthesis of Attachment Efficiencies Measured under Varying Environmental Conditions.

Park Y, Atwill ER, Hou L, Packman AI, Harter T.SourceLand, Air, and Water Resources, University of California , One Shields Ave., Davis, California 95616-8628, United States.
Environmental science & technology.Environ Sci Technol.2012 Sep 4;46(17):9491-500. Epub 2012 Aug 21.
An extensive set of column experiments was performed with freshly harvested Cryptosporidium parvum oocysts to evaluate the effects of solution chemistry, surface coatings, interactions with other suspended particles, and pore fluid velocity on the fate and transport of this widely occurring waterbor
PMID 22861686

Japanese Journal

大腸菌ワクチン投与後のホルスタイン母牛の初乳を給与された新生子牛におけるリンパ球動態とクリプトスポリジウム感染防御効果

青木美樹子,丹羽友一郎,小松司 [他]
産業動物臨床医学雑誌 2(1), 7-13, 2011-06
NAID 40018927401

Related Pictures

★リンクテーブル★

リンク元	「新興感染症」「クリプトスポリジウム症」「クリプトスポリジウム属」「クリプトスポリジウム・パルバム」「小形クリプトスポリジウム」
関連記事	「Cryptosporidium」「parvum」

「新興感染症」

Cryptosporidium parvum
	Immunofluorescence image of C. parvum oocysts.
Scientific classification
(unranked):	Sar
Phylum:	Apicomplexa
Class:	Conoidasida
Subclass:	Coccidiasina
Order:	Eucoccidiorida
Family:	Cryptosporidiidae
Genus:	Cryptosporidium
Species:	C. parvum
Binomial name
	Cryptosporidium parvum;

　　[★]

英: emerging infectious disease
関: 感染症、再興感染症

「これまで知られていなかったが、1973年以降に見いだされた病原体」
http://www.mext.go.jp/a_menu/shotou/clarinet/004/004/003.pdfより

新たにヒトでの感染が証明された疾患、あるいはそれまでその土地では存在しなかったが新たにそこでヒトの病気として現れてきたものなどとされています。原因が不明であった疾患のうち病原物質が明らかとなり、地域あるいは国際的に多くの人の健康に対して問題となるものも新興感染症の概念の中に含まれます。

一覧

年	病原微生物	種類	疾患
1973	Rotavirus	ウイルス	小児下痢症
1975	Parvovirus B19	ウイルス	伝染性紅班
1976	Cryptosporidium parvum	寄生虫	下痢症
1977	Eboravirus	ウイルス	エボラ出血熱
	Legionella pneumophila	細菌	レジオネラ症
	Hantaanvirus	ウイルス	腎症候性出血熱
	Campylobacter jejuni	細菌	下痢症
1980	Human T-lymphotropic virus-1	ウイルス	成人T細胞白血病
1980	Hepatitis D virus	ウイルス	D型ウイルス肝炎
1981	TSST-1-producing Staphylococcus aureus	細菌	毒素性ショック症候群
1982	Escherichia coli 0157:H7	細菌	腸管出血性大腸炎、溶血性尿毒症症候群
	Human T-lymphotropic virus-2⁽¹⁾	ウイルス	白血病
	Borrelia burgobrferi	細菌	ライム病
	Rickttsia japonica	細菌	日本紅斑熱
1983	Human immunodeficiency virus	ウイルス	後天性免疫不全症候群
1983	Helicobacter pylori	細菌	胃炎(胃潰瘍、十二指腸潰瘍、胃癌、MALTリンパ腫)
1985	Enterocytozoon bieneusi	寄生虫	持続性下痢症
1986	Cyclospora cayetanensis	寄生虫	持続性下痢症
1986	Prion⁽²⁾	プリオン	牛海綿状脳症
1988	Human herpesvirus-6	ウイルス	突発性発疹症
1988	Hepatitis E virus	ウイルス	E型肝炎
1989	Ehriichia chaffeensis	細菌	エールリキア症
	Hepatitis C virus	ウイルス	C型肝炎
	Clamydia pneumoniae	細菌	肺炎、気管支炎
1991	Guanarito virus	ウイルス	ベネズエラ出血熱
	Encephalitozoon heilem	寄生虫	結膜炎
	Newspecis of Babesia	寄生虫	非定型性バベシア症
1992	Vibrio choerae 0139	細菌	新型コレラ
1992	Bartoneiia henselae	細菌	猫ひっかき病
1993	Sin Nombre virus	ウイルス	ハンタウイルス肺症候群(成人呼吸窮迫症候群)
1993	Encephalitozoon cuniculi	真菌	ミクロスポリドーシス
1994	Sabia virus	ウイルス	ブラジル出血熱
1994	Hendra virus	ウイルス	ウイルス性脳炎
1995	Human herpesvirus-8	ウイルス	カポジ肉腫
1995	Hepatitis G virus	ウイルス	G型肝炎
1996	TSE causing agent	プリオン	新型クロイツフェルト・ヤコブ病
1996	Australian bat lyssavirus	ウイルス	ウイルス性脳炎
1997	Influenza A/H5N1	ウイルス	トリ型インフルエンザのヒト感染
1999	Nipa hvirus	ウイルス	急性脳炎
2003	SARS coronavirus	ウイルス	重症急性呼吸器症候群(SAR)

(1)1983年か？
(2)1982年か？

-感染症

「クリプトスポリジウム症」

　　[★]

英: cryptosporidiosis

病原体

原虫の一種

参考

1. wikipedia en

http://en.wikipedia.org/wiki/Cryptosporidiosis

「クリプトスポリジウム属」

　　[★]

ラ: Cryptosporidium
関: 原虫、胞子虫類

水道の浄水への混入が問題となる　→　Cryptosporidium parvum

「クリプトスポリジウム・パルバム」

　　[★]

ラ: Cryptosporidium parvum、C. parvum
関: 小形クリプトス・リジウム

「小形クリプトスポリジウム」

　　[★]

ラ: Cryptosporidium parvum
関: クリプトス・リジウム・パルバム

「Cryptosporidium」

　　[★]

クリプトス・リジウム、リプトス・リジウム属、Cryptosporidium属

関: cryptosporidial、Cryptosporidiidae

関: Cryptosporidiosi s

「parvum」

　　[★]

Cryptosporidium parvum

[1] ”Cryptosporidiosis.” Laboratory Identification of Parasites of Public Health Concern. CDC. 5 Sept 2007. <http://www.dpd.cdc.gov/dpdx/HTML/Cryptosporidiosis.htm>

[2] DuPont HL, Chappell CL, Sterling CR, Okhuysen PC, Rose JB, Jakubowski W (March 1995). "The infectivity of Cryptosporidium parvum in healthy volunteers". N. Engl. J. Med. 332 (13): 855–9. doi:10.1056/NEJM199503303321304. PMID 7870140.

[nejm.org-3] DuPont et al "The Infectivivty of Cryptosporidium parvum in healthy Volunteers" http://www.nejm.org/doi/pdf/10.1056/NEJM199503303321304

[4] ”Surveillance for Waterborne-Disease Outbreaks -- United States, 1993-1994” CDC. 1996. <http://www.cdc.gov/mmwr/preview/mmwrhtml/00040818.htm>

[5] Deng, M.; Lancto, C. A.; Abrahamsen, M. S. (2004). "Cryptosporidium parvum regulation of human epithelial cell gene expression". International Journal for Parasitology 34 (1): 73–82. doi:10.1016/j.ijpara.2003.10.001. PMID 14711592.

[aem.asm.org-6] Robertson et al "Survival of Cryposporidium parvum oocysts under various environmental pressures" http://aem.asm.org/content/58/11/3494.full.pdf+html

[Abrahamsen_2004-7] Abrahamsen MS, Templeton TJ; et al. (2004). "Complete genome sequence of the apicomplexan, Cryptosporidium parvum". Science 304 (5669): 441–5. doi:10.1126/science.1094786. PMID 15044751. Retrieved 2008-05-25. (subscription required)

[8] Barnes DA, Bonnin A, Huang JX; et al. (October 1998). "A novel multi-domain mucin-like glycoprotein of Cryptosporidium parvum mediates invasion". Mol. Biochem. Parasitol. 96 (1–2): 93–110. doi:10.1016/S0166-6851(98)00119-4. PMID 9851610.

[9] Cevallos AM, Bhat N, Verdon R; et al. (September 2000). "Mediation of Cryptosporidium parvum Infection In Vitro by Mucin-Like Glycoproteins Defined by a Neutralizing Monoclonal Antibody". Infect. Immun. 68 (9): 5167–75. doi:10.1128/IAI.68.9.5167-5175.2000. PMC 101770. PMID 10948140.

匿名

検索

案内

案内

Cryptosporidium parvum