Protozoa

Amoebae

Protozoa are single-celled eukaryotic organisms, some of which are pathogenic to humans. Amoebae move and feed by means of pseudopodia.

• Naegleria fowleri: Known as the 'brain-eating amoeba', causes primary amoebic meningoencephalitis.

Flagellates

Flagellates are protozoa that move using one or more whip-like flagella.

• Trichomonas vaginalis: Causes trichomoniasis, a sexually transmitted infection.

• Giardia intestinalis: Causes giardiasis, a diarrheal disease.

• Trypanosoma brucei gambiense: Causes African sleeping sickness.

• Trypanosoma cruzi: Causes Chagas disease.

Apicomplexans

Apicomplexans are obligate intracellular parasites with complex life cycles.

• Plasmodium falciparum: Causes malaria.

• Toxoplasma gondii: Causes toxoplasmosis.

• Cryptosporidium parvum: Causes cryptosporidiosis, a diarrheal disease.

Helminths

Helminths are parasitic worms, classified as cestodes (tapeworms), trematodes (flukes), and nematodes (roundworms).

Cestodes (Tapeworms)

• Taenia solium: Pork tapeworm, causes taeniasis and neurocysticercosis.

Trematodes (Flukes)

• Schistosoma japonicum: Causes schistosomiasis, a disease of the blood vessels.

Nematodes (Roundworms)

• Ascaris lumbricoides: Causes ascariasis, an intestinal infection.

• Enterobius vermicularis: Pinworm, causes enterobiasis.

• Necator americanus: Hookworm, causes anemia and malnutrition.

• Wuchereria bancrofti: Causes lymphatic filariasis (elephantiasis).

Fungi

Fungi are eukaryotic organisms that can be pathogenic, opportunistic, or dermatophytic.

True Pathogens

• Histoplasma capsulatum: Causes histoplasmosis, a respiratory disease.

• Blastomyces dermatitidis: Causes blastomycosis.

• Coccidioides immitis: Causes coccidioidomycosis (Valley fever).

Opportunistic Pathogens

• Candida albicans: Causes candidiasis (yeast infection).

• Aspergillus fumigatus: Causes aspergillosis, especially in immunocompromised hosts.

Dermatophytes

• Trichophyton tonsurans: Causes tinea capitis (scalp ringworm).

Pathology, Transmission, and Diagnosis

General Pathology

• Protozoa and helminths cause disease by damaging host tissues, inducing inflammation, or obstructing organs.

• Fungi can cause superficial, subcutaneous, or systemic infections.

Transmission

• Protozoa: Often transmitted via contaminated water, food, or insect vectors.

• Helminths: Transmission can occur via ingestion of eggs/larvae, skin penetration, or insect vectors.

• Fungi: Inhalation of spores, direct contact, or overgrowth in immunocompromised hosts.

Diagnosis

• Microscopy: Identification of eggs, larvae, cysts, or adult organisms in clinical samples.

• Serology: Detection of antibodies or antigens.

• Molecular methods: PCR for DNA detection.

Key Medical Terms

• Hepatosplenomegaly: Enlargement of the liver and spleen.

• Granuloma: Localized area of inflammation.

• Contagion: Spread of disease from one individual to another.

• Encephalitis: Inflammation of the brain.

Summary Table: Major Pathogenic Eukaryotes

Additional info:

• Some details, such as specific life cycles, intermediate hosts, and advanced diagnostic methods, were inferred from standard microbiology knowledge to provide a complete study guide.

• For each organism, knowing the life cycle, transmission, and clinical presentation is crucial for diagnosis and treatment.