The Eukaryotes of Microbiology

Practice flashcards covering the general characteristics, classification, and diseases associated with protozoans, parasitic helminths, and fungi based on the lecture material.

Protozoans

Unicellular eukaryotic parasites that lack tissues and share similarities in cell structure, nutrition, life cycle, and biochemistry.

Trophozoite

The motile feeding stage of a protozoan that requires ample food and moisture to stay active.

Cyst

A dormant resting stage of some protozoans that is resistant to heat, drying, and chemicals, and is an important factor in the spread of disease.

Schizogony

Asexual reproduction by multiple fission, occurring in all protozoans.

Conjugation

The process of sexual reproduction in many protozoans.

Entamoeba histolytica

A protozoan that moves through pseudopods and causes amoebic dysentery.

Naegleria fowleri

A protozoan that causes a fatal infection of the brain, often identified from the CSF of patients with PAM.

Plasmodium

A genus of nonmotile intracellular parasites that cause malaria and are spread by the bite of the Anopheles mosquito.

Malarial paroxysm

Cycles of feeling very hot and very cold associated with malaria infection.

Cryptosporidium

A nonmotile protozoan transmitted through contaminated water or food that causes watery diarrhea.

Toxoplasma gondii

A nonmotile protozoan spread by cats (feces) or raw beef that is dangerous to pregnant women as it can damage or kill a fetus.

Balantidium coli

A protozoan motile through cilia that causes an intestinal infection (dysentery) and is transmitted by pigs.

Giardia lamblia

A flagellated protozoan that causes intestinal infection and malabsorption syndrome, an issue in fat uptake after infection.

Trichomonas vaginalis

A flagellated protozoan that causes a sexually transmitted infection and exists only in the trophozoite form.

Trypanosoma brucei

A flagellated protozoan spread by the tsetse fly that causes African sleeping sickness.

Trypanosoma cruzi

A flagellated protozoan spread by the triatomine (kissing) bug that causes Chagas disease in South America.

Monoecious

A term describing helminths that have both male and female sex organs on the same worm.

Dioecious

A term describing helminths where the sexes are separate.

Intermediate host

The host in which larval development of a parasitic helminth occurs.

Definitive host

The host in which the adulthood and mating of a parasitic helminth occur.

Nematodes

Roundworms characterized by a complete digestive tract, a protective surface cuticle, and spines/hooks on the mouth.

Enterobius vermicularis

Also known as the pinworm, it is the most common helminthic infection in the US.

Necator americanus

Known as the hookworm, it is transmitted through soil contaminated with human feces and causes anemia.

Trichinella

The causative agent of trichinellosis, contracted by consuming undercooked pork or bear meat where larvae encyst in muscle tissue.

Dracunculus

Known as the Guinea worm, it creates a hole in the skin with a burning sensation that causes the host to release larvae into water.

Trematodes

Also known as flukes, these are nonsegmented, flattened flatworms with sucking mouthparts.

Cestodes

Also known as tapeworms, these are segmented flatworms.

Clonorchis

The liver fluke found in parts of Asia, spread by eating undercooked fish.

Paragonimus

The lung fluke spread by coughing up sputum into water and eating undercooked crustaceans.

Schistosoma

The blood fluke whose larvae penetrate the skin from contaminated water to infect blood vessels.

Scolex

The head of a tapeworm (Taenia or Diphyllobothrium) that features hooks and/or suckers.

Proglottids

Regenerative segments of a tapeworm that contain an ovary and testes producing fertilized eggs.

Mycosis

A general term for an illness caused by fungi.

Dimorphic

The ability of some fungi to exist as either yeast or molds depending on growth conditions, such as temperature.

Chitin

The material found in fungal cell walls, distinct from the cellulose found in plant cell walls.

Ergosterols

Sterols found in fungal cell membranes that serve as targets for antifungal drugs, unlike cholesterol in animal membranes.

Hyphae

Long filaments that make up multicellular fungi (molds).

Mycelium

A mass of hyphae that gives molds a cottony, hairy, or velvety texture.

Septate hyphae

Fungal hyphae that are divided into sections by cross walls.

Coenocytic hyphae

Fungal hyphae that are not divided by cross walls; also known as nonseptate hyphae.

Budding

The asexual reproduction process in yeasts where cells may produce chains called pseudohyphae.

Saprobes

Fungi that live off dead plants and animals; most fungi belong to this group.

Mucor

A mold typically found indoors that can cause respiratory infections, primarily in immunocompromised individuals.

Aspergillus

A common mold in soil that can form fungal balls in the lungs of immunocompromised patients.

Tinea

Cutaneous mycoses of the skin caused by Microsporum and Epidermophyton, including ringworm and athlete's foot.

Histoplasma

A dimorphic fungus that turns into a yeast at $37\,^{\circ}\text{C}$ in the body after inhalation of spores from bird or bat feces.

Candida

A yeast that is part of the normal microbiota but can cause candidiasis, vaginal yeast infections, and thrush.

Cryptococcus

A yeast that causes meningitis or pulmonary infections and is identified by encapsulated cells in India ink stains of CSF.

Aflatoxin

A potentially lethal poison produced by the fungus Aspergillus flavus in contaminated grain.