Protozoa B50-B64

Protozoa (Greek: the "first animal") refers to a group of different unicellular, eukaryotic organisms (= living beings with cell nucleus and cell membrane). Protozoa, together with unicellular algae and fungi, form the lower realm of the protists. This includes all unicellular organisms with a real cell nucleus. Algae and fungi are assigned to the plant kingdom. Protozoa belong to the animal kingdom (animal unicellular organisms). Protozoa differ considerably in size and morphology. As heterotrophic organisms, they require substances that are built up by other organisms for their metabolism. A distinction is made between:

• commensal forms
• mutualistic forms
• parasitic forms.

The parasitic forms have an important role as pathogens in animals and humans. About 40 human pathogenic species are known.

Among the most important pathogens are:

• Trypanosomes (sleeping sickness; Chagas disease)
• Leishmania(Leishmaniasis)
• Trichomonas vaginalis ( trichomoniasis)
• Giardia intestinalis ( Lambliasis)
• Amoebae ( Amoebiasis)
• Toxoplasma gondii ( Toxoplasmosis)
• Isospora ( isosporiasis)
• Cryptosporidium (Cryptosporidiosis)
• Plasmodium ( Malaria)
• Microspora (microsporidosis)
• Pneumocystis carinii (pneumocystosis).

Some of these diseases partly show primary (see leishmaniasis) dermatological manifestations, partly cutaneous symptoms accompany the primary disease process (see Chagas disease); other diseases are listed here only as indications.

Profile:

• Definition: Group of different unicellular, eukaryotic organisms (= living beings with cell nucleus and cell membrane). Protozoa, together with unicellular algae and fungi, form the protist underclass. This includes all unicellular organisms with a real cell nucleus. Algae and fungi are assigned to the plant kingdom. Protozoa belong to the animal kingdom (animal unicellular organisms). Protozoa differ considerably in size and morphology. As heterotrophic organisms, they require substances that are built up by other organisms for their metabolism. A distinction is made between:
  • commensal forms
  • mutualistic forms
  • parasitic forms.

  • The parasitic forms have an important role as pathogens in animals and humans. About 40 human pathogenic species are known

• Pathogen: Among the most important pathogens are:
  • Trypanosomes (sleeping sickness; Chagas disease)
  • Leishmania(Leishmaniasis)
  • Trichomonas vaginalis(trichomoniasis)
  • Giardia intestinalis(Lambliasis)
  • Amoebae(Amoebiasis)
  • Toxoplasma gondii(Toxoplasmosis)
  • Isospora(isosporiasis)
  • Cryptosporidium (Cryptosporidiosis)
  • Plasmodium(malaria)
  • Microspora (microsporidosis)
  • Pneumocystis carinii (pneumocystosis).

• Note: Some of these diseases show primary (s. leishmaniasis) dermatological manifestations, some cutaneous symptoms accompany the primary disease process (s. Chagas disease); other diseases are listed here only as indications.