HOMO SAPIENS DISEASES - VIRIDIPLANTAE GROUP
(see also Physiology of Viridiplantae and Antimicrobials for Eukaryal organisms sections)
 

Chlorophyta

• Trebouxiophyceae
• Chlorellales
• Chlorellaceae

=> chlorellosis
• Prototheca, a genus of ubiquitous achlorophyllic algae. It is a unicellular organism that reproduces asexually by internal septation and cleavage, to form sporangia (6 to 26 mm in diameter) containing sporangiospores. Prototheca is a ubiquitous organism that lives saprophytically on decaying organic matter. It has been recovered from fresh and marine water, fish tanks, swimming pools, waste stabilization ponds, vegetables, and meat products such as beef, pork, crabs, and clams

=> prototechosis : 90 cases mostly in immunocompromised patients, mostly due to systemic or topical steroids
• Prototheca wickerhamii

Epidemiology : the first case of multiorgan systemic protothecal infection was described by Cox et al. in 1974. The patient was a 29-year-old man who had involvement of the liver, peritoneum, lymph nodes, skin, and blood. A similar case of visceral protothecosis, in a 39-year-old man, was later described; the infection mimicked sclerosing cholangitis. A third case of visceral protothecosis, in a 13-year-old Japanese boy, was described in 1992. In this patient, the liver, spleen, small intestine, lymph nodes, and central nervous system were involved. The other cases of systemic protothecosis consisted of an AIDS patient with protothecal meningitis, a Hickman catheter-related algaemia in a 7-year-old child on chemotherapy for Hodgkin’s disease, and two cases of non-catheter-related protothecal sepsis in patients with a lung transplant and leukemia, respectively. In all but one, the species involved was P. wickerhamii. From the lung transplant patient, P. zopfii was isolated. Systemic algaemia, with recovery of Prototheca species from the blood, occurred in only 5 cases, one associated with myasthenia gravis (papulonodular eruption on his right hand, from which P. wickerhamii was subsequently isolated. According to his wife, the patient had a persistent rash on his right hand for approximately 6 to 8 weeks prior to admission. It is possible that this initial rash was a localized mild infection due to P. wickerhamii, which then disseminated as a systemic algaemia, when the patient suffered an acute exacerbation of his myasthenia gravis. The role of the prior plasmapheresis in the progression of his protothecal disease is unknown. Alternatively, the cutaneous eruption could have resulted from hematogenous seeding of a preceding algaemia. Prototheca species have previously been isolated from stools, urine, and sputum. For our patient, urine and sputum cultures were negative for Prototheca species; a stool specimen was not cultured for Prototheca. Cultures of 4 additional intravenous catheter tips were negative. The source of infection, in this patient, remains undetermined.^ref)
• chronic cutaneous and/or subcutaneous protothecosis (38%) : non-tender, pyoderma-like or diffusely infiltrating erythematous papules and plaques on the extensor side of the extremities (elbow and foot ) or face. Infections of immunosuppressed patients tend to be more florid
• systemic protothecosis (usually oligosymptomatic)
• disseminated disease (23%)
• algaemia (23%)
• pulmonary infection (8%)
• synovitis of olecranon bursa (olecranon bursitis) or other fibrous tissue (8%)

Therapy : surgical excision
• protothecosis of the urinary tract
• intestinal protothecosis in a patient with chronic mucocutaneous candidiasis : gastroenteritis
• Prototheca zopfii (3 biotypes)

The first case of human P. zopfii infection was described by Davis et al. in 1964. The patient was a rice farmer in Sierra Leone with a localized chronic skin lesion.
Therapy : local infiltration of fluconazole 3 ml (2 mg/ml)/week x 4.
Epidemiology : worldwide
Transmission : milk as well as dairy products from infected Bos taurus, where severe protothecal mastitis is a result of adventitious infection from the environment
Laboratory examinations : typical endospores with morula-like structures in skin biopsy specimens, PAS⁺, Gomori's methenamine silver⁺, and Gridley fungus stain⁺. Prototheca species may be confused with yeasts such as Candida and Cryptococcus species on Gram stains.
Therapy :
• i.v. amphotericin B > 5-fluorocytosine in cases of disseminated disease and in patients with severe underlying illness or with immunosuppression or immunocompromise
• azole antifungals and surgery should be reserved for patients with more localized disease. Itraconazole appears to be the most effective agent of this drug class, and it should be administered at 200 mg/day for 2 months.

---

Copyright © 2001-2005 Daniele Focosi. All rights reserved  |  Terms of use  | Legal notices
About this site  |  Site map  |  Acknowledgements | Open forum  |  Tell a friend about this site  |  Current link partners
 Abbreviations and acronyms  |  Medical terminology  |  Add a link  |  Translate this site into your favourite language  |  Softwares

---

---

Search EntrezNCBI Web Site-------------PubMedGeneLocusLinkTaxonomyProteinNucleotideStructureGenomeBooksCancerChromosomesConserved Domains3D DomainsGEO ProfilesGEO DatasetsHomoloGeneJournalsMeSHNLM CatalogOMIMPMCPopSetPubChem BioAssayPubChem CompoundPubChem SubstanceSNPUniGeneUniSTS for

Search AboutAltaVistaAsk JeevesDictionaryDirectHitExciteFindWhatGoogleGoogle GroupsHotBotLookSmartLycosMetacrawlerMetaLocateNorthern LightOpen DirectorySnapThesaurusWebcrawlerYahoo for

Search Medical Dictionary  for