Protothecosis
| Protothecosis | |
|---|---|
 | |
| Histologicstain of aPrototheca zopfiiinfection in a dog | |
| Specialty | Infectious diseases |
Protothecosis,otherwise known asAlgaemia,is a disease found indogs,cats,cattle,and humans caused by a type ofgreen algaknown asProtothecathat lackschlorophylland enters the human or animal bloodstream. It and its close relativeHelicosporidiumare unusual in that they are actually green algae that have become parasites.[1]The two most common species arePrototheca wickerhamiiandPrototheca zopfii.Both are known to cause disease in dogs, while most human cases are caused byP. wickerhami.[2]Protothecais found worldwide insewageandsoil.Infection is rare despite high exposure, and can be related to a defectiveimmune system.[3]In dogs, females andColliesare most commonly affected.[4]
The first human case was identified in 1964 inSierra Leone.[5]
Cause
[edit]
Protothecahas been thought to be a mutant ofChlorella,a type of single-celled green alga. However, whileChlorellacontainsgalactoseandgalactosaminein the cell wall,Protothecalacks these. Also,Chlorellaobtains its energy throughphotosynthesis,whileProtothecaissaprotrophic,feeding on dead and decaying organic matter. WhenProtothecawas first isolated fromslime fluxof trees in 1894, it was thought to be a type offungus.[6]Its size varies from 2 to 15micrometres.[7]
Treatment
[edit]Treatment withamphotericin Bhas been reported.[8]
In cattle
[edit]Cattle can be affected by protothecalenteritisandmastitis.[9]Protothecal mastitis isendemicworldwide, although most cases of infected herds have been reported inGermany,theUnited States,andBrazil.[10]
In dogs
[edit]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 includediarrhea,weight loss, weakness, inflammation of the eye (uveitis),retinal detachment,ataxia,andseizures.[11]
Dogs with acute blindness and diarrhea that developexudativeretinal detachmentshould be assessed for protothecosis.[6]Diagnosis is throughcultureor finding the organism in abiopsy,cerebrospinal fluid,vitreous humour,or urine. Treatment of the disseminated form in dogs is very difficult, although use ofantifungalmedication has been successful in a few cases.[4]Prognosisfor 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.[3]
See also
[edit]References
[edit]- ^Tartar A, Boucias DG, Adams BJ, Becnel JJ (2002)."Phylogenetic analysis identifies the invertebrate pathogen Helicosporidium sp as a green alga (Chlorophyta)".Int J Syst Evol Microbiol.52(Pt 1): 273–9.doi:10.1099/00207713-52-1-273.PMID11837312.
- ^Leimann B, Monteiro P, Lazéra M, Candanoza E, Wanke B (2004). "Protothecosis".Med Mycol.42(2): 95–106.doi:10.1080/13695780310001653653.PMID15124862.
- ^abHosaka S, Hosaka M (2004)."A case report of canine protothecosis".J Vet Med Sci.66(5): 593–7.doi:10.1292/jvms.66.593.PMID15187378.
- ^abEttinger, Stephen J., Feldman, Edward C. (1995).Textbook of Veterinary Internal Medicine(4th ed.). W.B. Saunders Company.ISBN978-0-7216-6795-9.
- ^Lass-Flörl C, Fille M, Gunsilius E, Gastl G, Nachbaur D (2004)."Disseminated infection with Prototheca zopfii after unrelated stem cell transplantation for leukemia".J. Clin. Microbiol.42(10): 4907–8.doi:10.1128/JCM.42.10.4907-4908.2004.PMC522359.PMID15472379.
- ^abHollingsworth S (2000). "Canine protothecosis".Vet Clin North Am Small Anim Pract.30(5): 1091–101.doi:10.1016/S0195-5616(00)05008-7.PMID11033876.
- ^Lee W, Lagios M, Leonards R (1975)."Wound infection by Prototheca wickerhamii, a saprophytic alga pathogenic for man".J Clin Microbiol.2(1): 62–6.doi:10.1128/jcm.2.1.62-66.1975.PMC274126.PMID1225929.
- ^Mohabeer AJ, Kaplan PJ, Southern Jr PM, Gander RM (1997)."Algaemia due to Prototheca wickerhamii in a patient with myasthenia gravis".Journal of Clinical Microbiology.35(12): 3305–3307.doi:10.1128/jcm.35.12.3305-3307.1997.PMC230169.PMID9399541.
- ^Osterstock J, Mansell J, Roussel A (2005)."Protothecal enteritis as a cause of protein-losing enteropathy in a bull".J Am Vet Med Assoc.227(9): 1476–9, 1418.doi:10.2460/javma.2005.227.1476.PMID16279394.
- ^Roesler U, Hensel A (2003)."Longitudinal analysis of Prototheca zopfii-specific immune responses: correlation with disease progression and carriage in dairy cows".J Clin Microbiol.41(3): 1181–6.doi:10.1128/JCM.41.3.1181-1186.2003.PMC150299.PMID12624049.
- ^Gionfriddo JR (March 2007). "An unusual cause of blindness in a Siberian husky".Veterinary Medicine.102(3): 172–178.