Title: Protothecosis

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| name            = Protothecosis
| image           = Prototheca zopfii.jpg
| caption         = [[Histology|Histologic]] stain of a ''Prototheca zopfii'' infection in a dog
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'''Protothecosis,''' otherwise known as [[Algaemia]], is a disease found in [[dog]]s, [[cat]]s, [[cattle]], and humans caused by a type of [[green alga]] known as ''[[Prototheca]]'' that lacks [[chlorophyll]] and enters the human or animal bloodstream. It and its close relative ''[[Helicosporidium]]'' are unusual in that they are actually green algae that have become parasites.&lt;ref name=Tartar&gt;{{cite journal |vauthors=Tartar A, Boucias DG, Adams BJ, Becnel JJ |title=Phylogenetic analysis identifies the invertebrate pathogen Helicosporidium sp as a green alga (Chlorophyta) |journal=Int J Syst Evol Microbiol |volume=52 |pages=273–9 |year=2002 |pmid=11837312 |issue=Pt 1 |doi=10.1099/00207713-52-1-273|doi-access=free }}&lt;/ref&gt;  The two most common species are ''[[Prototheca wickerhamii]]'' and ''[[Prototheca zopfii]]''. Both are known to cause disease in dogs, while most human cases are caused by ''P. wickerhami''.&lt;ref name=Leimann&gt;{{cite journal |vauthors=Leimann B, Monteiro P, Lazéra M, Candanoza E, Wanke B |title=Protothecosis |journal=Med Mycol |volume=42 |issue=2 |pages=95–106 |year=2004 |pmid=15124862 |doi=10.1080/13695780310001653653}}&lt;/ref&gt; ''Prototheca'' is found worldwide in [[sewage]] and [[soil]]. Infection is rare despite high exposure, and may be related to a defective [[immune system]].&lt;ref name=Hosaka&gt;{{cite journal |vauthors=Hosaka S, Hosaka M |title=A case report of canine protothecosis |journal=J Vet Med Sci |volume=66 |issue=5 |pages=593–7 |year=2004 |pmid=15187378 |doi=10.1292/jvms.66.593|doi-access=free }}&lt;/ref&gt;  In dogs, female [[Collie]]s are most commonly affected.&lt;ref name=Ettinger_1995&gt;{{cite book|author1=Ettinger, Stephen J. |author2=Feldman, Edward C. |title=Textbook of Veterinary Internal Medicine|edition=4th|publisher=W.B. Saunders Company|year=1995|isbn=978-0-7216-6795-9}}&lt;/ref&gt;

The first human case was identified in 1964 in [[Sierra Leone]].&lt;ref&gt;{{cite journal |vauthors=Lass-Flörl C, Fille M, Gunsilius E, Gastl G, Nachbaur D |title=Disseminated infection with Prototheca zopfii after unrelated stem cell transplantation for leukemia |journal=J. Clin. Microbiol. |volume=42 |issue=10 |pages=4907–8 |year=2004 |pmid=15472379 |doi=10.1128/JCM.42.10.4907-4908.2004 |pmc=522359}}&lt;/ref&gt;

==Cause==
[[File:Prototheca wickerhamii.hematoxylin eosin stain.jpg|thumb|left|Photomicrograph of Prototheca wickerhamii infection in a human. Note the floret-like arrangements. Hematoxylin and eosin stain.]]
[[File:Prototheca wickerhamii.GMS.jpg|thumb|Photomicrograph of Prototheca wickerhamii infection in a human. Note the floret-like arrangements. Gomori methenamine silver(GMS) stain.]]
[[File:Prototheca wickerhamii.PAS.jpg|thumb|Photomicrograph of Prototheca wickerhamii infection in a human. Note the floret-like arrangements. Periodic acid-Schiff(PAS) stain.]]
''Prototheca'' has been thought to be a mutant of ''[[Chlorella]]'', a type of single-celled green alga. However, while ''Chlorella'' contains [[galactose]] and [[galactosamine]] in the cell wall, ''Prototheca'' lacks these. Also, ''Chlorella'' obtains its energy through [[photosynthesis]], while ''Prototheca'' is [[saprotroph]]ic, feeding on dead and decaying organic matter.  When ''Prototheca'' was first isolated from [[slime flux]] of trees in 1894, it was thought to be a type of [[fungus]].&lt;ref name=VCNA&gt;{{cite journal |author=Hollingsworth S |title=Canine protothecosis |journal=Vet Clin North Am Small Anim Pract |volume=30 |issue=5 |pages=1091–101 |year=2000 |pmid=11033876|doi=10.1016/S0195-5616(00)05008-7 }}&lt;/ref&gt; Its size varies from 2 to 15 [[micrometre]]s.&lt;ref&gt;{{cite journal |vauthors=Lee W, Lagios M, Leonards R |title=Wound infection by Prototheca wickerhamii, a saprophytic alga pathogenic for man |journal=J Clin Microbiol |volume=2 |issue=1 |pages=62–6 |year=1975 |doi=10.1128/jcm.2.1.62-66.1975 |pmid=1225929 |pmc=274126}}&lt;/ref&gt;

==Treatment==
Treatment with [[amphotericin B]] has been reported.&lt;ref&gt;{{Cite journal| pmid = 9399541| year = 1997| last1 = Mohabeer | first1 = A. J.| last2 = Kaplan|first2=P. J.| last3 = Southern Jr|first3=P. M.| last4 = Gander|first4=R. M.| title = Algaemia due to Prototheca wickerhamii in a patient with myasthenia gravis| volume = 35| issue = 12| pages = 3305–3307| journal = Journal of Clinical Microbiology| doi = 10.1128/jcm.35.12.3305-3307.1997| pmc = 230169}}&lt;/ref&gt;

==In cattle==
Cattle can be affected by protothecal [[enteritis]] and [[mastitis]].&lt;ref name=Osterstock&gt;{{cite journal |vauthors=Osterstock J, Mansell J, Roussel A |title=Protothecal enteritis as a cause of protein-losing enteropathy in a bull |journal=J Am Vet Med Assoc |volume=227 |issue=9 |pages=1476–9, 1418 |year=2005 |pmid=16279394 |doi=10.2460/javma.2005.227.1476|doi-access=free }}&lt;/ref&gt; Protothecal mastitis occurs worldwide, although most cases of have been reported from [[Germany]], the [[United States]], and [[Brazil]].&lt;ref name=Roesler&gt;{{cite journal |vauthors=Roesler U, Hensel A |title=Longitudinal analysis of Prototheca zopfii-specific immune responses: correlation with disease progression and carriage in dairy cows |journal=J Clin Microbiol |volume=41 |issue=3 |pages=1181–6 |year=2003 |pmid=12624049 |doi=10.1128/JCM.41.3.1181-1186.2003 |pmc=150299}}&lt;/ref&gt;

==In dogs==
Disseminated protothecosis is most commonly seen in dogs. The algae enters the body through the mouth or nose and causes infection in the intestines. From there it can spread to the eye, brain, and kidneys. Symptoms can include [[diarrhea]], weight loss, weakness, inflammation of the eye ([[uveitis]]), [[retinal detachment]], [[ataxia]], and [[seizure]]s.&lt;ref&gt;{{cite journal | last = Gionfriddo | first = Juliet R. | title = An unusual cause of blindness in a Siberian husky | journal = Veterinary Medicine | volume = 102 | issue = 3 | pages = 172–178 |date=March 2007 }}&lt;/ref&gt;

Dogs with acute blindness and diarrhea that develop [[exudate|exudative]] [[retinal detachment]] should be assessed for protothecosis.&lt;ref name=VCNA/&gt; Diagnosis is through [[microbiological culture|culture]] or finding the organism in a [[biopsy]], [[cerebrospinal fluid]], [[vitreous humour]], or urine. Treatment of the disseminated form in dogs is very difficult, although use of [[antifungal drug|antifungal]] medication has been successful in a few cases.&lt;ref name=Ettinger_1995/&gt; [[Prognosis]] for cutaneous protothecosis is guarded and depends on the surgical options. Prognosis for the disseminated form is grave. This may be due to delayed recognition and treatment.&lt;ref name=Hosaka/&gt;

== See also ==
* [[Progressive disseminated histoplasmosis]]
* [[List of cutaneous conditions]]
* [[Chlorellosis]]

== References ==
{{Reflist}}
== External links ==
{{Medical resources
| DiseasesDB      = 33989
| ICD11           = {{ICD11|1G60.2}}
| ICD10           = {{ICD10|B|88|8|b|85}} ([[ILDS]] B88.83)
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| OMIM            =
| MedlinePlus     =
| eMedicineSubj   = derm
| eMedicineTopic  = 348
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| SNOMED CT       = 240915002
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{{Chromalveolate diseases}}

[[Category:Dog diseases]]
[[Category:Cat diseases]]
[[Category:Bovine diseases]]
[[Category:Infectious diseases]]
[[Category:Protozoal diseases]]