Final Part 1 Micro

In the dormant cyst form, Giardia is protected from the environment by a shell composed of __________.

chitin

A housefly can transmit diseases as a (biological/fomite/mechanical) vector.

mechanical

What tools would the doctor use to diagnose this disease?

identification of the budding yeast in KOH-prepared samples of skin scrapings or sputum from the patient

In cestodes, gravid proglottids are found __________.

in the middle and at the end of the strobila

What was the source of the infection?

inhalation of spores from the bat guano

Which of the following is NOT a means of preventing leishmaniasis?

keeping dogs as pets in human homes

Label the morphological characteristics of the tapeworm. Drag the appropriate labels to their respective targets.

pic on my phone

Enterobius vermicularis are commonly known as (pinworms/hookworms/tapeworms) because of the shape of the female's tail.

pinworms

An intestinal parasite that is an emerging disease in North America, (Cryptosporidium/Cyclospora/Entamoeba) causes a watery diarrhea with fever.

Cyclospora

What is the vector for this disease?

sand flies

Giardiasis is one of the more common GI diseases in the United States. Both animals and humans are at risk for developing this disease. In which of these cases would a human be most likely to become infected by this pathogen?

A family hiking in the woods allows its dog to drink from a nearby stream. When they return home, the dog becomes sick with diarrhea in the house and family members must clean up the mess.

90-95% of the population of the Ohio River Valley has been exposed to Histoplasma capsulatum, but relatively few individuals are diagnosed with histoplasmosis. Why is this so?

A healthy immune system clears the infection before signs and symptoms can appear in these individuals.

Which of the following organisms can cause water-borne diarrheal disease?

Entamoeba histolytica Vibrio cholerae Cryptosporidium enteritis

A patient at a clinic complains of diarrhea that is occasionally bloody and has persisted for several days. A microscopic examination of a stool sample reveals the presence of very round cysts. These signs are consistent with infection by

Entamoeba histolytica.

Which of the following is the most common parasitic worm in the United States?

Enterobius vermicularis

All tapeworms are intestinal parasites that completely lack digestive systems.

True

Anemia is a common consequence of hookworm infestation.

True

Leishmania species cause systemic disease as well as superficial diseases.

True

Look carefully at the peripheral blood smear. What parasite is present in the blood?

Trypanosoma brucei

When does the dormant cyst excyst in the human body?

Upon entry into the intestines.

Examine the photomicrograph and then drag the organism classification to correctly complete the sentence. The organism appears to be an

amoeba.

The parasites classified as Nematodes

are known as roundworms.

Opportunistic fungi

are normal microbiota for many individuals.

The most common nematode infection worldwide is (ascariasis/filariasis/pinworms).

ascariasis

After an initial infection with Naegleria, what body system will be invaded by the parasite next?

central nervous system

Which of the following organisms can colonize the nasal cavity and enter the brain to cause meningoencephalitis?

Naegleria

Which of the following fungal infections was extremely rare prior to the AIDS epidemic?

Pneumocystis pneumonia

Based on the clinical history and presentation, what disease is this soldier most likely to have?

cutaneous leishmaniasis

The infectious stage of a beef tapeworm for humans is the

cysticerci in beef.

Infections with (dermatophytes/pathogens/opportunists) are commonly acquired by person-to-person direct contact.

dermatophytes

The cell membranes of fungi contain (cholesterol/ergosterol/fatty acid) which is a target of some antifungal treatments.

ergosterol

Aspergillus causes both mycoses and mycotoxicosis. .

f

Fungi that cause systemic mycoses are uniformly acquired by ingesting contaminated food.

f

The most severe form of malaria, called "blackwater fever" is caused by Plasmodium (falciparum/malariae/ovale/vivax).

falciparum

A large number of antifungal agents are available for treating fungal infections.

false

A person who shares a hairbrush with other family members is most likely to be at risk for which of the following mycoses?

favus

Trypanosoma cruzi is introduced into the body by

feces containing trypomastigotes contaminating a bite wound.

Elephantiasis is caused by

filarial roundworms.

Most mycoses are difficult to treat because

fungal cells provide few targets for selective toxicity.

Severe frothy diarrhea with a "rotten-egg" smell accompanied by abdominal pain, bloating, and fever are signs and symptoms consistent with

giardiasis.

Nematodes such as Ascaris infect the __________ by way of the __________.

intestinal tract; lungs

Histoplasma capsulatum

is an intracellular parasite.

The pathogen, Giardia intestinalis, is diplomonad meaning __________.

it has 2 nuclei

What medication should this man receive to treat this disease?

melarsoprol

All of the true pathogen fungi discussed in this chapter are

members of the Ascomycota and are dimorphic.

The ________ spreads more parasitic diseases to humans than any other vector.

mosquito

Peanut butter was prepared using peanut on which Aspergillus had grown. Several people who ate it suffered from (mycetismus/mycetoma/Aspergillus causes both mycoses and mycotoxicosis. ).

mycotoxicosis

Eating undercooked (fish/pork/snails/vegetables) can result in infestation with Taenia solium.

pork

Which of the following contributes to infection with Trichomonas vaginalis?

preexisting disease (chlamydia, for example)

Greasy, frothy diarrhea with the smell of __________ may indicate giardiasis.

rotten eggs

Most fungi exist as (parasites/saprobes/autotrophs) and function as the major decomposers of organic material.

saprobes

Blastomyces dermatitidis occurs in the (southeastern/central/southwestern/western) part of North America.

southeastern

Which of the following poses the greatest risk of contracting schistosomiasis?

swimming in contaminated water

The definitive host of a parasite is

where the mature form of the parasite occurs.

Ringworm is caused by

worms infected with fungi invading the skin.

What is the vector for African sleeping sickness?

tsetse flies

What is the mortality rate for untreated cases of African sleeping sickness?

100

What is the treatment for cutaneous leishmaniasis?

application of topical insecticides

Identify the genera of parasites in the photographs. Drag the appropriate labels to their respective targets.

1) fecal: Gridia intestinalis. It causes Griadiasis. 2) anal : Enterobious vermicularis. It causes itching in the anal.It is a pinworm infection. 3) blood: Plasmodium falciparum 4) fecal: Schistosoma mansoni 5) vaginal: Trypanosoma vaginalis causes trichomoniosis 6) Blood: Trypanosoma cruzi 7) Entamoeba histolytica 8) Cryptosporidium parvum

A contact lens wearer and cat owner begins to experience problems with her eye. The eye is inflamed and painful, and examination of the eye reveals that the conjunctiva is ulcerating. Which of the following parasites is most likely responsible?

Acanthamoeba

What is the name of the disease this man is suffering from?

African sleeping sickness

The tsetse fly is responsible for the spread of

African sleeping sickness.

Antibody tests are commonly used for rapid diagnosis of many types of infection. However, they are NOT particularly useful for diagnosis of histoplasmosis. Why is this so?

Antibody tests are not useful because in endemic areas over 95% of the population has been infected without contracting the disease.

An avid gardener in eastern North America begins to have a fever and cough. A sample from her lungs contains yeast cells and pus. She may be infected with

Blastomyces dermatitidis.

Which of the following is an opportunistic pathogenic fungus in humans?

Candida albicans

A patient infected with a protozoan parasite who also exhibits congestive heart failure is most likely in the final stages of which of the following diseases?

Chagas' disease

Triatoma, commonly called "kissing bugs," are vectors of

Chagas' disease.

Which of the following can mimic tuberculosis by causing the formation of large cavities in the lungs when the infection becomes chronic?

Coccidioides

Humans are the only reservoir for (Balantidium/Entamoeba/Giardia), an intestinal parasite that causes diarrhea.

Entamoeba

Histoplasma and Coccidioides produce tuberculosis-like damage to the lungs that can be seen on X-ray images.

Histoplasma and Coccidioides produce tuberculosis-like damage to the lungs that can be seen on X-ray images.

This disease is also known as Spelunker's Disease and Cave Disease. What is the most likely cause of Nate's illness?

Histoplasma capsulatum

Why are subcutaneous mycoses uncommon?

Injury is necessary to introduce the fungus into the tissue.

Which of the following statements about Candida is FALSE?

It is easily treated with topical antifungals in immunocompromised patients.

How serious cases of giardiasis currently treated in the United States?

Metronidazole

There are four species of Plasmodium that cause the disease malaria, of which P. falciparum is the most virulent. P. falciparum is transmitted by a mosquito vector to a human host. Can all mosquitoes transmit malaria? Why or why not?

Only male Anopheles mosquitoes can transmit the malarial parasite to the human hosts because they take a blood meal in order to be fertile.

Patty returns later and says she found amoeba trophozoites and cysts. Since amoebae are not uncommon in fresh water and they are not generally pathogenic, she has done a serological test using antibodies and, unfortunately, has discovered that the organism is Entamoeba histolytica. Which of the following should be employed to avoid further problems with the Entamoeba histolytica?

Post warning that the water should be filtered before drinking. Advise doctors to prescribe iodoquinol to people who have been drinking the lake water and now have diarrhea. Advise people that have been drinking the lake water, but do not have symptoms, to visit their doctor and ask about a prescription for paromomycin.

A person reports to a clinic complaining of fever and abdominal pain. The abdomen is swollen, and blood tests indicate liver damage. A stool sample is examined under a microscope and found to contain eggs with a spine projecting from its surface. The indications are consistent with infection with

Schistosoma mansoni.

Why is snail fever a common name for infections with Schistosoma?

Snails are the intermediate host.

A human fecal sample is examined and found to contain a few strobila. The person is probably infected with

Taenia.

What is the best way to prevent disease caused by Aspergillus species?

The best way to prevent disease caused by Aspergillus species is to take steps to maintain a healthy immune system.

A child with a pinworm infection is successfully treated, but later suffers a relapse. Which of the following best explains the relapse?

The child's clothing and bedding were not properly laundered.

In the life cycle of Giardia intestinalis, the small intestine plays a pivotal role. What is the importance of the small intestine in the development of giardiasis?

The small intestine is where the Giardia cyst releases the trophozoite and it can adhere to the epithelial cells and begin to multiply.

Which of the following regarding all of the tapeworms that infect humans is TRUE?

They all have non-human intermediate hosts.

Pathogenically, how does Giardia produce symptoms in humans?

They consume blood from the intestinal walls.

The parasite (Leishmania/Toxoplasma/Trichomonas) is an obligate parasite that is incapable of surviving long outside the human host and is transmitted almost exclusively via sexual activity.

Trichomonas

Which of the following is the most common parasitic disease in industrialized nations?

Trichomonas infection

The presence of active motile multiflagellated trophozoites in vaginal or urethral secretion is indicative of infection with

Trichomonas vaginalis.

Which of the following nematodes can be transmitted by mosquitoes?

Wuchereria bancrofti

Drag the symptoms and mode of transmission to the correct organism.

__Entamoeba histolytica dysenteryfecal-oral ___Acanthamoeba keratitis ---Naegleria meningoencephalitisinhalation

To prevent infection with giardiasis, one should __________ when drinking from a possible contaminated water source.

heat the water for 5 minutes

The number of cases of schistosomiasis has decreased over the past few decades due to which of the following?

improvement in water systems

What is the name of the antifungal drug that Nate is taking? How likely is it that other scouts were infected during the caving camp out?

ketoconazole It is highly likely that 90% or more of the scouts will show evidence of infection (antibody formation). Only a small percentage of these will get sick.

Amoebae are a group of protozoa that move and feed using __________.

lobe-shaped pseudopods

Which of the following types of fungal disease is primarily the result of ingestion?

toxicosis

The (cestodes/nematodes/trematodes) are helminths with an incomplete digestive system.

trematodes

Dermatophytes, which live on the surface of the skin, are always pathogenic.

true