Microbiology Homework chapter 5.1

Label the image to examine the life and transmission cycle of Plasmodium.

1)Asexual phase: Blood is inoculated with sporozoites. 2)Pre-erythrocytic development: Schizogony occurs in liver cells generating numerous merozoites. 3)Erythrocytic phase: Merozoites in the bloodstream invade RBCs and convert to trophozoites, microgametocytes, and macrogametocytes. 4)Sexual phase: Fertilization of gametes occurs leading to the development of sporozoites.

It is thought that up to _____ of humans carry the protozoan, suggesting that it could be considered part of our ______. Studies have shown that persistent infection with T. gondii may negatively affect our mental health.

50%, microbiome

Choose the term that best describes the role of protozoan cysts.

Protozoan cysts are a survival form that allows them to survive adverse environmental conditions between hosts.

What locomotor structures might you see if you were observing a motile protozoan under an electron microscope?

Pseudopods, Flagella, Cilia

What term describes the transfer of helminth eggs from on host to another, such as between children sharing toys at daycare?

Cross-infection

The identification of which structures produced by the pathogen, in the stool specimen aided in the patient's diagnosis?

Cysts

The RN advises the student to cover skin and utilize insect protection measures. She also informs the importance of taking an anti-malarial drug. Which of the following drugs does the RN anticipate to be ordered prophylactically?

Quinine

Which of the following drugs will be useful in the treatment of this disease?

Antiprotozoal drugs

As depicted in this schematic, humans can become infected with Toxoplasma through what means? Check all that apply.

Consuming food or water contaminated with cat feces, Eating undercooked meats, Blood transfusions.

The RN anticipates the child will be worked up for pinworm infection. What is the causative organism?

Enterobius vermicularis

Giardia lamblia is a prokaryotic organism.

False

The gram stain would show red cells in clinical specimens from a patient infected with a protozoan

False

Toxoplasmosis is very uncommon in the United States.

False

How does this pathogenic protozoan leave the cat host?

Feces

What time of day would the RN advise the patient's mother to perform the test to assess for the presence of eggs produced by this organism?

First thing in the morning

What means of locomotion is used by Trypanosoma?

Flagella

Two different kinds of appendages may be found on eukaryotic cells that enable them to move. ______ are long slender locomotor appendages that are usually single and few in number, whereas _____ are appendages which are numerous and short.

Flagella, cilia

Which protozoan listed here also uses that same means of locomotion?

Giardia

Select all of the statements that apply to the pathogenesis of malaria to test your understanding of this disease.

Hypoglycemia is a symptom due to parasite metabolism of glucose. The liver and spleen become enlarged. RBCs adhere to blood vessels in the brain.

What insect is responsible for the transmission of malaria from on host to the next?

Mosquito

Toxoplasmosis is a TORCH infection. What does this mean?

It can be transmitted from mother to fetus.

Malaria is caused by protozoans in the genus ____, with five species largely responsible for the disease in humnas. The life cycle of the parasite can be divided into two stages; the ____ phase that takes place in humans and the ____ phase, which takes place in the ______.

Plasmodium, asexual, sexual, mosquito

The greatest increase in the number of reported cases of giardiasis occurred between which two months?

September and October

The causative agent of malaria belongs to which group of protozoa?

Sporozoa

What simple test may be performed to detect the eggs produced by this organism?

Tape test

Choose the most accurate description of a typical helminth lifestyle.

The helminth reproduces sexually and spends most of its life in either a single animal host or a series of animal hosts.

What would be the best hypothesis to explain why the highest incidence of giardiasis occurred in the summer and early fall?

These are the months when sunlight exposure is at its minimum.

The total number of cases in November exceed that of July and September combined.

True

The two major types of helminths based on body type are the ___, which include the tapeworms, and the ___, which are also known as nematodes.

flatworms; roundworms

The Plasmodium life cycle cannot continue in the human, and the _______ pass back into the mosquito when it feeds on infected blood.

gametocytes

Individuals with a healthy immune system may experience little or no symptoms if infected, but ________ patients will experience brain lesions and fatal heart and lung damage. Pregnant females are at great risk of passing the parasite to the ____, running the risk of _____, liver failure, or hydrocephalus.

immunosuppressed, fetus, stillbirth

The infection cycle between cats and other hosts (rodents and birds)involves _______ the pathogenic protozoan for transmission between hosts.

ingestion of

Protozoans would likely be ____ bacteria under the brightfield microscope.

larger than

Bacteria, archaea, and eukaryotes are believed to have evolved from a different kind of cell, known as the _____

last common ancestor

Cats are the only host in which Toxoplasma cna sexually reproduce. Therefore, cats are the _____ host for this protozoan.

definitive

Symptoms of malaria infection include all of the following, except ____

difficulty breathing (muscle aches, leathargy, headache)

During the life cycle, infective ____ are excreted in cat feces. They may infect humans that are in contact with cat litter boxes, or following ingestion of meat products from _______ that ingested the oocysts while grazing in infected areas.

oocysts, herbivorse

Which of these groups causes the most casualties on an annual basis globally?

protozoa

<The life cycle of Toxoplasma gondii and the toxoplasmosis.> Toxoplasma gondii is a flagellated _____ that is an obligate intracellular parasite. Its natural host is the ____ but it has little host specificity so it can infect over 200 species of birds and _____.

protozoan, feline, mammals

The asexual phase begins when the human is bitten by an Anopheles mosquito, injecting the ____ into the capillaries along with an anticoagulant. The cells circulate and enter the liver where they undergo _____; a form of asexual division producing numerous ______ within the hepatocytes.

sporozoites, schizogony, merozoites

When the liver cell ruptures, thousands of merozoites enter the circulation where they infect erythrocytes and convert to ______. Lysis of erythrocytes releases more merozoites, and this _______ phase is responsible for the synchronous symptoms seen in the infected host.

trophozoites, erythrocytic

Select characteristics exhibited by most protozoans.

unicellular, motile by means of flagella, cilia, or pseudopodia, Heterotrophic, 3~300 micrometer size range