Exam 3 - Protozoans

Trophozoite

Motile active state of a protozoan.

Fission

Breaking into two parts.

Budding

Formation of a smaller daughter cell that eventually breaks off.

Schizogony (Multiple Fission)

The nucleus divides many times. Cytoplasm surrounds each nucleus and separation follows.

Cyst

Protective capsule formed by a protozoan.

Excavata

A superkingdom of protozoans that posses a feeding groove within the cytoskeleton.

Giardia lamblia

Protozoan of superkingdom Excavata. Anaerobic and lacks mitochondria. Causes “beaver fever” and can be contracted in contaminated water and poorly washed or undercooked food. Cysts are resistant to cold and chlorination.

Flagyl (Metronidazole)

Medication used to fight anaerobic / faculatative anaerobic microbes such as Giardia lamblia.

Hydrogen sulfide

This distinctive odor can often be detected in cases of Giardiasis.

String Test

Can be used to diagnoses infection of Giardia lamblia.

Lactose intolerance and Bloating

Hallmark signs of Giardia infection.

Trichomonas vaginalis

Has an undulating membrane, no mitochondria, no cyst stage and is anaerobic. It is found in the vagina and male urinary tract. Can be transmitted via sexual intercourse and occassionaly towels.

Strawberry Cervix

Inflammed cervix that can be caused by Trichomonas vaginalis.

Flagyl (Metronidazole)

Used to treat trichomoniasis. Given to both sex partners.

Wet Mount

Used to diagnosis trichomoniasis.

Euglenozoa

Contains pathogenic members that are hemoflagellates.

Hemoflagellate

Flagellated parasite found in the blood. Spread by bite of blood feeding insect. Usually has a long slender body and undulating membrane.

Trypanosoma brucei

Causes african sleeping sickness.

Tsetse Fly

Vector that transmits african sleeping sickness.

Trypanosoma cruzi

Causes Chagas’ disease. Multiplies through schizogony. Resevoir is wild animals such as rodents, opossums and armadillos. Can cause heart disease, megacolon and achalasia.

Triatomine Bug

Transmits chagas disease.

Achalasia

Condition in which lower sphincter muscle cannot relax. Can happen as a result of chagas disease.

Dysphagia

Difficulty swallowing.

Botox

Treatment used on man who acquired chagas disease in Panama.

Pseudopods

Blunt, lobe-like projections of the cytoplasm that assist in cell movement.

Amoebozoa

Phylum consisting of protozoans that move by use of pseudopods.

Entamoeba histolytica

Only pathogenic ameba found in the human intestine. Humans are the only host. It can be anaerobic or microaerophilic. It feeds on and disolves the intestinal wall. Infections identified by presence of cysts in feces — especially ones that have ingested erythrocytes.

Amebic Dysentary

Blood and mucus in the stool caused by invasive Entamoeba histolytica.

Flagyl (Metronidazole)

Drug used to treat amebiasis.

Hepatic Portal System

This system can spread E. histolytica from the GI tract to the liver.

Naegleria fowleri

Brain-eating ameba. Found fee-living in warm ponds and streams, it enters through the nose and travels directly to the brain in people with poor immunity.

Olfactory Nerve

Route through which Naegleria fowleri travels to the brain from nasal mucosa.

Neti Pots

When these are used with tap water, infection with Naegleria fowleri may follow.

Primary Amebic Meningoencephalitis

Inflammation of the entire head caused by the brain-eating ameba.

Apicomplexa

Group of obligate intracellular parasites that are named for the presence of speical organelles at their tips — these usually contain enzymes to penetrate host tissues. They are not motile in their mature form. They have complex life cycles that usually involve transmission between several hosts.

Plasmodium

The causative agent of malaria. This protozoan grows in human RBCs and in the liver through schizogony. Its development is regulated by host body temperature — meaning mature parasites are released during the night.

Malaria

Disease characterized by fever, vomiting and headache occuring every few days. It is spread by mosquitos.

Anopheles Mosquito

The vector that spreads malaria.

Blood Smear

Way in which malaria is diagnosed.

Chloroquine

A derivative of quinine that is given to people traveling to areas with a high risk of malaria.

Thrombocytopenia

A condition that may correlate with increased number of parasites, resulting in worse outcomes for patients with malaria. This can be caused by aspirin, which inactivates platlets.

Signet Ring

Plasmodium in red blood cells is recognizable because it has this shape.

Toxoplasma gondii

The causative agent of toxoplasmosis. Often associated the domestic cats, from which cysts can either be inhaled or swallowed. It is especially dangerous to pregnant women because it is teratogenic. It is diagnosed through presence of antibodies or tissue examination.

Teratogenic

Describes an agent that can cause damage to a developing embryo of fetus.

Schizophrenia

Risk of this condition appears to increase following infection by mumps, cytomegalovirus or Toxoplasma gondii.

Cryptosporidium

The causative agent of cryptosporidiosis. It causes cholera-like diarrhea for approximately two weeks in humans, rodents, dogs and cats. It occurs when cysts are ingested and invade epithelial cells of the intestine. Can be life threatening to immunodeficient individuals. Usually spread through water contaminated by animal waste. Infectious dose is low and it cannot be killed through chlorination.

Nitazoxanide

The drug recommended to treat cryptosporidiosis. It can also be used to treat giardiasis.