Med Micro: MasteringMicrobiology CH 22 & 23
KOH preparations dissolve which of the following?
keratin
In cestodes, gravid proglottids are found __________.
nearest the end of the strobila
Which of the following diseases caused by Histoplasma capsulatum is due in part to an immune response?
ocular histoplasmosis
The symptoms and mode of transmission to the correct zygomycoses.
Cutaneous Zygomycota: contact, skin lesions
The salivary glands of a tsetse fly will contain which of the following forms of Trypanosoma brucei?
trypomastigotes
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.
Which of the following pieces of equipment could be used to make a product that would transmit Zygomycota spores via inhalation?
A nasal spray bottling machine
Would a person living in Canada be able to contract malaria from a mosquito bite?
A person living in Canada would not be likely to contract malaria from a mosquito bite because Plasmodium falciparum cannot complete its life cycle at a temperature below 20 degrees C.
Which of the following represents the MOST LIKELY route of transmission for Michael's infection?
Foodborne - Eating undercooked, unwashed, or otherwise contaminated food that contained parasitic propagules
The symptoms and mode of transmission to the correct zygomycoses.
Gastrointestinal Zygomycota: abdominal pain, vomiting, ingestion
Drag the symptoms and mode of transmission to the correct organism.
Entamoeba histolytica: fecal-oral, dysentery
Which of the following species of mushrooms produces hallucinogens?
Amanita muscaria
Which of the following organisms can cause water-borne diarrheal disease?
Vibrio cholerae Cryptosporidium enteritis Entamoeba histolytica
Based on its patterns of disease, which of the following would you expect to be the most common type of treatment for aspergillosis?
allergy medications
Changes in farming practices are most useful in the control of which of the following diseases?
amebiasis
Which of the following groups of protozoan parasites is typically nonmotile?
apicomplexans
After an initial infection with Naegleria, what body system will be invaded by the parasite next?
central nervous system
A patient with cryptococcal infection begins complaining of headache, dizziness, nausea, and neck stiffness. Which of the following specimens would be most useful in diagnosis of this patient's condition?
cerebrospinal fluid
To diagnose giardiasis, microscopic evaluation is required and it is often hard to diagnose. Why do you think this is so?
Multiple stool samples are required to diagnose giardiasis because the cysts and trophozoites are shed only intermittently.
Drag the symptoms and mode of transmission to the correct organism.
Naegleria: meningoencephalitis, inhalation
Episodes of fever in a patient with malaria coincide with which of the following events?
erythrocyte lysis
A person who shares a hairbrush with other family members is most likely to be at risk for which of the following mycoses?
favus
Examine the image seen through the microscope and select the best answer.
fungi
The number of cases of schistosomiasis has decreased over the past few decades due to which of the following?
improvement in water systems
Exposure to which of the following is the LEAST likely means of contracting a mycosis?
infected people
Nematodes such as Ascaris infect the __________ by way of the __________.
intestinal tract; lungs
Mycetismus is another name for __________.
mushroom poisoning
Which of the following structures associated with Toxoplasma is directly responsible for the migration of the pathogen from rodents to cats?
pseudocysts
Which of the following types of disease is the most common manifestation of coccidioidomycosis?
pulmonary
A patient shows signs of Malassezia infection. Which of the following would NOT be a suitable treatment for this infection?
shaving hair
Which of the following poses the greatest risk of contracting schistosomiasis?
swimming in contaminated water
Which of the following forms of aspergillosis would most likely be observed in an AIDS patient?
systemic aspergillosis
Which of the following phases of malaria occurs in humans?
the erythrocytic cycle
Which of the following is a predisposing factor for the formation of noninvasive aspergillomas?
tuberculosis
Which of the following is necessary for successful xenodiagnosis of Chagas' disease?
uninfected vectors
What method is the LEAST effective for controlling malaria?
vaccination against P. falciparum
Which type of leishmaniasis is most likely fatal?
visceral leishmaniasis
A South American patient who makes his living as a farm worker sees a physician concerning painful ulcerated lesions of the gums, tongue, and lips. A history reveals that the patient has been experiencing tiredness, coughing, and weight loss for the past several weeks. Which of the following would you expect to find upon microscopic examination of KOH-treated specimens from this patient?
yeast cells with buds in a "steering wheel" formation
A laboratory technician grows a clinical specimen of Blastomyces dermatitidis at 37 degrees Celsius in the laboratory. Which of the following will be visible when a sample of this culture is viewed under the microscope?
yeasts
What is the correct sequence of events for the life cycle of the pork tapeworm, T. solium?
1. Eggs are produced by adult tapeworms living in the definitive host 2. Eggs are released into the environment in the feces 3. Pigs eat grass contamined, or fertilized, with human feces 4. Inside the intermediate host, the eggs mature into larvae and encyst in the hosts muscles 5. The definitive host ingests the larvae and becomes infected
The diseases caused by Aspergillus species are considered opportunistic. Which of the groups listed here would be most likely to become infected with Aspergillus?
AIDS patients
Corneal replacement is sometimes necessary as a result of which of the following diseases?
Acanthamoeba keratitis
Drag the symptoms and mode of transmission to the correct organism.
Acanthamoeba: keratitis
Which of the following should be employed to avoid further problems with the Entamoeba histolytica?
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. Advise doctors to prescribe iodoquinol to people who have been drinking the lake water and now have diarrhea. Post warning that the water should be filtered before drinking.
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.
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
Which of the following sources of fungal intoxications can play a beneficial role as pharmaceuticals?
Claviceps purpurea
Which of the following can mimic tuberculosis by causing the formation of large cavities in the lungs when the infection becomes chronic?
Coccidioides
Why does Dr. Clark request stool samples for examination?
He will have the laboratory prepare the samples for an ova and parasite (O&P) exam. Fresh or preserved stool samples can be observed microscopically for the presence of parasites or their eggs/cysts. Tapeworms are pathogens of the gastrointestinal tract; as a natural progression of digestion some of the tapeworm pieces will be expelled along with fecal matter.
Why do we see an increase in the levels of IgE antibody in Michael's serum?
IgE is the class of antibodies involved in hypersensitivities such as allergies and parasitic infections.
What is unusual about the treatment for Pneumocystis pneumonia?
It involves the use of antiprotozoan drugs.
Label the morphological characteristics of the tapeworm.
Look in textbook
Label the stages of the Plasmodium life cycle as well as the form of the parasite in each stage
Look in textbook
Which of the following is the most important arthropod vector of human diseases?
Mosquitoes
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 female Anopheles mosquitoes can transmit the malarial parasite to a human host because they are the only ones who take a blood meal from the host.
What is the treatment that Dr. Clark will most likely recommend?
Praziquantel or albendazole, drugs that target eukaryotic parasites with minimal side effects in the host.
The symptoms and mode of transmission to the correct zygomycoses.
Rhinocerebral Zygomycota: fever, sinus pain, nasal discharge, inhalation of spores
Drag the appropriate label to the figure. Not all labels will be used.
Sporangiophore (stem), Sporangiospores (around the bulb thing), Sporangium (the bulb thing), Aseptate hypha (the transverse stem thing)
Which of the following organisms is most likely the causative agent of Michael's tapeworm infection?
Taenia solium
Compare the anatomy of the tapeworm (Image C) to the anatomy of the roundworm (Image D). Given that both are parasitic worms, which of the following reasons best explains why the tapeworm is flat?
Tapeworms utilize diffusion to absorb nutrients from the host's digestive 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.
The main symptoms of malaria are cycles of fever, anemia, and fatigue. During which stage of malaria would these symptoms be most apparent?
The erythrocytic phase of the life cycle is most likely to cause these symptoms.
Examine the photomicrograph and then drag the organism classification to correctly complete the sentence.
The organism appears to be an amoeba
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.
Canines that are household pets are at very low risk for Echinococcus infection for which of the following reasons?
Their diet is usually carefully monitored.
Which of the following genera is the most contagious?
Trichophyton
Why was Dr. Clark worried about tapeworm infection in other body sites?
When tapeworm larvae escape the stomach, they can travel to other parts of the body such as muscles, the liver, the eye, and even the brain to form cysticerci. The presence of T. solium in the brain can result in neurocysticercosis, a serious condition which has symptoms resembling those of brain tumors or epilepsy.
Characterizing the fungal groups. Based on the microscopic image in Part B, the organism appears to belong to the division __________.
Zygomycota
All of the following diseases can be diagnosed from stool samples EXCEPT__________.
leishmaniasis
Which of the following arthropod vectors may spend its entire lifetime in association with a single individual?
lice
Amoebae are a group of protozoa that move and feed using __________.
lobe-shaped pseudopods
A physician wants to use amphotericin B in the treatment of a patient with blastomycosis, but he is concerned about possible toxicity of the drug. If itraconazole is used instead, which of the following adjustments to the treatment plan will be necessary?
longer administration of the drug
Which of the following is an INCORRECT association?
tinea capitis: groin