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*Microbiology Extern > 8.1 Parasitology > Flashcards

8.1 Parasitology Flashcards

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1
Q

The incorrect match between organism and the appropriate diagnostic procedure is:
A. Onchocerca volvulus—examination of skin snips
B. Cryptosporidium spp.—modified acid-fast stain
C. Enterobius vermicularis—routine ova and parasite examination
D. Schistosoma haematobium—examination of urine sediment

A

C. Enterobius vermicularis—routine ova and parasite examination

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2
Q

In a patient with diarrhea, occasionally Entamoeba histolytica/E. dispar (four nucleated cysts, no chromatoidal bars) are identified as being present; however, these cells, which are misdiagnosed as protozoa, are really:
A. Macrophages
B. Polymorphonuclear leukocytes (PMNs)
C. Epithelial cells
D. Eosinophils

A

B. Polymorphonuclear leukocytes (PMNs)

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3
Q

Charcot-Leyden crystals in stool may be associated with an immune response and are thought to be formed from the breakdown products of:
A. Neutrophils
B. Eosinophils
C. Monocytes
D. Lymphocytes

A

B. Eosinophils

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4
Q

Parasitic organisms that may be transmitted sexually do not include:
A. Entamoeba gingivalis
B. Dientamoeba fragilis
C. Trichomonas vaginalis
D. Diphyllobothrium latum

A

D. Diphyllobothrium latum

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5
Q

The incorrect match between the organism and one method of acquiring the infection is:
A. Trypanosoma brucei rhodesiense—bite of sand fleas
B. Giardia lamblia (G. intestinalis, G. duodenalis)—ingestion of water contaminated with cysts
C. Hookworm—skin penetration of larvae from soil
D. Toxoplasma gondii—ingestion of infected raw or rare meats

A

A. Trypanosoma brucei rhodesiense—bite of sand fleas

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6
Q

Upon examination of stool material for Cystoisospora belli, one would expect to see:
A. Cysts containing sporozoites
B. Precysts containing chromatoidal bars
C. Oocysts that are modified acid-fast positive
D. Sporozoites that are hematoxylin positive

A

C. Oocysts that are modified acid-fast positive

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7
Q

Which specimen is the least likely to provide recovery of Trichomonas vaginalis?
A. Urine
B. Urethral discharge
C. Vaginal discharge
D. Feces

A

D. Feces

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8
Q

Which of the following is the best technique to identify Dientamoeba fragilis in stool?
A. Formalin concentrate
B. Trichrome-stained smear
C. Modified acid fast–stained smear
D. Giemsa stain

A

B. Trichrome-stained smear

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9
Q

One of the following protozoan organisms has been implicated in waterborne and foodborne outbreaks within the United States. The suspect organism is:
A. Pentatrichomonas hominis
B. Dientamoeba fragilis
C. Giardia lamblia (G. intestinalis, G. duodenalis)
D. Balantidium coli

A

C. Giardia lamblia (G. intestinalis, G. duodenalis)

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10
Q

Gram staining of a sample from a gum lesion showed what appeared to be amoebae. A trichrome smear showed amoebae with a single nucleus and partially digested PMNs. The correct identification is:
A. Trichomonas tenax
B. Entamoeba histolytica/Entamoeba dispar
C. Entamoeba gingivalis
D. Entamoeba polecki

A

C. Entamoeba gingivalis

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11
Q

An E. histolytica (true pathogen) trophozoite has the following characteristics:
A. Compact karyosome in the nucleus, ingested RBCs, and clear pseudopodia
B. Ingested RBCs, clear pseudopodia, and uneven chromatin on the nuclear membrane
C. Ingested RBCs, clear pseudopodia, and large glycogen vacuoles in cytoplasm
D. Large, blotlike karyosome, ingested white blood cells (WBCs), and granular pseudopods

A

A. Compact karyosome in the nucleus, ingested RBCs, and clear pseudopodia

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12
Q

A 12-year-old girl is brought to the emergency room with meningitis and a history of swimming in a warm-water spring. Motile amoebae that measure 10 μm in size are seen in CSF and are most likely:
A. Iodamoeba bütschlii trophozoites
B. Endolimax nana trophozoites
C. Dientamoeba fragilis trophozoites
D. Naegleria fowleri trophozoites

A

D. Naegleria fowleri trophozoites

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13
Q

Characteristics of the rhabditiform (noninfective) larvae of Strongyloides stercoralis include a:
A. Short buccal capsule and large genital primordium
B. Long buccal capsule and pointed tail
C. Short buccal capsule and small genital primordium
D. Small genital primordium and notch in tail

A

A. Short buccal capsule and large genital primordium

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14
Q

Visceral larva migrans is associated with which of the following organisms and diagnostic method?
A. Toxocara—serology
B. Onchocerca—skin snips
C. Dracunculus—skin biopsy
D. Angiostrongylus—CSF examination

A

A. Toxocara—serology

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15
Q

The following organisms are linked with specific, relevant information. The incorrect combination is:
A. Strongyloides stercoralis—internal autoinfection
B. Echinococcus granulosus—hydatid examination
C. Toxoplasma gondii—serology
D. Balantidium coli—common in the United States

A

D. Balantidium coli—common in the United States

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16
Q

Examination of 24-hour unpreserved urine specimen is sometimes helpful in the recovery of:
A. Trichomonas vaginalis trophozoites
B. Schistosoma haematobium eggs
C. Enterobius vermicularis eggs
D. Strongyloides stercoralis larvae

A

B. Schistosoma haematobium eggs

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17
Q

The examination of sputum may be necessary to diagnose infection with:
A. Paragonimus westermani
B. Trichinella spiralis
C. Wuchereria bancrofti
D. Fasciola hepatica

A

A. Paragonimus westermani

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18
Q

Two helminth eggs that may resemble one another are:
A. Diphyllobothrium latum and Paragonimus westermani
B. Opisthorchis sinensis and Fasciolopsis buski
C. Taenia saginata and Hymenolepis nana
D. Ascaris lumbricoides and Trichostrongylus

A

A. Diphyllobothrium latum and Paragonimus westermani

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19
Q

Eating poorly cooked infected pork can lead to an infection with:
A. Taenia solium and Trichinella spiralis
B. Taenia saginata and Hymenolepis nana
C. Trichuris trichiura and Hymenolepis diminuta
D. Diphyllobothrium latum and Ascaris lumbricoides

A

A. Taenia solium and Trichinella spiralis

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20
Q

An operculated cestode egg that can be recovered from human feces is:
A. Clonorchis sinensis
B. Diphyllobothrium latum
C. Paragonimus westermani
D. Dipylidium caninum

A

B. Diphyllobothrium latum

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21
Q

The adult tapeworm of Echinococcus granulosus is found in the intestine of:
A. Dogs
B. Sheep
C. Humans
D. Cattle

A

A. Dogs

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22
Q

In infections with Taenia solium, humans can serve as the:
A. Definitive host
B. Intermediate host
C. Either the definitive or the intermediate host
D. None of the above

A

C. Either the definitive or the intermediate host

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23
Q

Humans acquire infections with Diphyllobothrium latum adult worms by:
A. Ingestion of freshwater crabs
B. Skin penetration of cercariae
C. Ingestion of water chestnuts
D. Ingestion of raw freshwater fish

A

D. Ingestion of raw freshwater fish

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24
Q

Humans can serve as both the intermediate and definitive host in infections caused by:
A. Enterobius vermicularis
B. Hymenolepis nana
C. Schistosoma japonicum
D. Ascaris lumbricoides

A

B. Hymenolepis nana

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25
Q

Babesia is an organism that has been implicated in disease from both splenectomized and nonsplenectomized patients. Morphologically, the parasites resemble:
A. Plasmodium falciparum rings
B. Leishmania donovani amastigotes
C. Trypanosoma cruzi trypomastigotes
D. Microsporidian spores

A

A. Plasmodium falciparum rings

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26
Q

Organisms (and infections) that under normal conditions cannot be transmitted in the laboratory are:
A. Cryptosporidium—cryptosporidiosis
B. Taenia solium—cysticercosis
C. Ascaris lumbricoides—ascariasis
D. Enterobius vermicularis—pinworm infections

A

C. Ascaris lumbricoides—ascariasis

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27
Q

Toxoplasma gondii is characterized by:
A. Possible congenital infection and ingestion of oocysts
B. Cosmopolitan distribution and possible difficulties with interpretation of serological results
C. None of the above
D. Both A and B

A

D. Both A and B

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28
Q

Oocysts of Cryptosporidium spp. can be detected in stool specimens by using:
A. Modified acid-fast stain
B. Gram stain
C. Methenamine silver stain
D. Trichrome stain

A

A. Modified acid-fast stain

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29
Q

Which microfilariae are usually not found circulating in peripheral blood?
A. Brugia malayi
B. Wuchereria bancrofti
C. Onchocerca volvulus
D. Loa loa

A

C. Onchocerca volvulus

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30
Q

Massive hemolysis, blackwater fever, and central nervous system involvement are most common with:
A. Plasmodium vivax
B. Plasmodium falciparum
C. Plasmodium ovale
D. Plasmodium malariae

A

D. Plasmodium malariae

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31
Q

Organisms that should be considered in a nursery school outbreak of diarrhea include:
A. Endolimax nana, Giardia lamblia (G. intestinalis, G. duodenalis), and Entamoeba coli
B. Giardia lamblia (G. intestinalis, G. duodenalis), Dientamoeba fragilis, and Cryptosporidium parvum
C. Cryptosporidium spp., Trichomonas vaginalis, and Entamoeba coli
D. Trichomonas hominis, Dientamoeba fragilis, and Endolimax nana

A

B. Giardia lamblia (G. intestinalis, G. duodenalis), Dientamoeba fragilis, and Cryptosporidium parvum

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32
Q

The incorrect match between disease and symptoms is:
A. Paragonimiasis—hemoptysis
B. Cryptosporidiosis—watery diarrhea
C. Toxoplasmosis in compromised host—central nervous system symptoms
D. Enterobiasis—dysentery

A

D. Enterobiasis—dysentery

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33
Q

The formalin-ether (ethyl acetate) concentration procedure for feces is used to demonstrate:
A. Motility of helminth larvae
B. Protozoan cysts and helminth eggs
C. Formation of amoebic pseudopods
D. Trophozoites

A

B. Protozoan cysts and helminth eggs

34
Q

Cysts of Iodamoeba bütschlii typically have:
A. Chromatoidal bars with rounded ends
B. A heavily vacuolated cytoplasm
C. A large glycogen vacuole
D. Many ingested bacteria and yeast cells

A

C. A large glycogen vacuole

35
Q

The miracidial hatching test helps to demonstrate the viability of eggs of:
A. Taenia species
B. Schistosoma species
C. Hookworm species
D. Opisthorchis species

A

B. Schistosoma species

36
Q

Organisms that should be considered in a waterborne outbreak of diarrheal disease include:
A. Giardia lamblia (G. intestinalis, G. duodenalis) and Cryptosporidium spp.
B. Endolimax nana and Entamoeba histolytica
C. Blastocystis spp. and Trichomonas vaginalis
D. Toxoplasma gondii and Schistosoma mansoni

A

A. Giardia lamblia (G. intestinalis, G. duodenalis) and Cryptosporidium spp.

37
Q

Fecal immunoassays have become more commonly used to diagnose infections with:
A. Endolimax nana and Blastocystis spp.
B. Giardia lamblia (G. intestinalis, G. duodenalis) and Cryptosporidium spp.
C. Ascaris lumbricoides and Trichuris trichiura
D. Strongyloides stercoralis and Trichomonas vaginalis

A

B. Giardia lamblia (G. intestinalis, G. duodenalis) and Cryptosporidium spp.

38
Q

The most common infections with the microsporidia often originate in:
A. The lung
B. The nervous system
C. The gastrointestinal tract
D. Mucocutaneous lesions

A

C. The gastrointestinal tract

39
Q

Eye infections with Acanthamoeba spp. have most commonly been traced to:
A. Use of soft contact lenses
B. Use of hard contact lenses
C. Use of contaminated lens care solutions
D. Failure to remove lenses while swimming

A

C. Use of contaminated lens care solutions

40
Q

Select the most sensitive recovery method for Acanthamoeba spp. from lens care solutions or corneal biopsies.
A. The trichrome staining method
B. The use of monoclonal reagents for the detection of antibody
C. The use of non-nutrient agar cultures seeded with Escherichia coli
D. The Giemsa stain method

A

C. The use of non-nutrient agar cultures seeded with Escherichia coli

41
Q

The microsporidia are organisms (now classified with the fungi) that have been implicated in human disease primarily in:
A. Immunocompromised patients
B. Pediatric patients under age 5 years
C. Adult patients with congenital immunodeficiencies
D. Patients who have been traveling in the tropics

A

A. Immunocompromised patients

42
Q

When staining Cystoisospora belli oocysts with modified acid-fast stains, the important difference between these methods and the acid-fast stains used for acid-fast bacilli (AFB) is:
A. The staining time is much longer with regular AFB acid-fast stains.
B. The decolorizer is much weaker than acid alcohol used for AFB decolorizing.
C. A counterstain must be used for the modified methods.
D. The stain is more concentrated when staining for AFB.

A

B. The decolorizer is much weaker than acid alcohol used for AFB decolorizing.

43
Q

The incorrect match between symptoms and disease is:
A. Dysentery and amebiasis
B. Malabsorption syndrome and giardiasis
C. Cardiac involvement and chronic Chagas disease
D. Myalgias and trichuriasis

A

D. Myalgias and trichuriasis

44
Q

The incorrect match between organism and characteristic is:
A. Chilomastix mesnili and Shepherd’s crook and lemon shape
B. Plasmodium malariae and “band trophozoite”
C. Hymenolepis nana and striated shell
D. Wuchereria bancrofti and sheathed microfilariae

A

C. Hymenolepis nana and striated shell

45
Q

The incorrect match between method and method objective is:
A. Direct wet examination and detection of organism motility
B. Knott concentration and the recovery of operculated helminth eggs
C. Baermann concentration and the recovery of Strongyloides
D. Permanent stained fecal smear and confirmation of protozoa

A

B. Knott concentration and the recovery of operculated helminth eggs

46
Q

The incorrect match between organism and characteristic/diagnostic method is:
A. Dientamoeba fragilis and tetrad karyosome in the nucleus
B. Toxoplasma gondii and diagnostic serology
C. Echinococcus granulosus and daughter cysts
D. Schistosoma mansoni and egg with terminal spine

A

D. Schistosoma mansoni and egg with terminal spine

47
Q

There are few procedures considered STAT in parasitology. The most obvious situation would be:
A. Ova and parasite examination for giardiasis
B. Baermann concentration for strongyloidiasis
C. Blood films for malaria
D. Culture of amebic keratitis

A

C. Blood films for malaria

48
Q

An immunosuppressed man has several episodes of pneumonia, intestinal pain, sepsis with gram-negative rods, and a history of military service in Southeast Asia 20 years earlier. The most likely cause is infection with:
A. Trypanosoma cruzi
B. Strongyloides stercoralis
C. Naegleria fowleri
D. Paragonimus westermani

A

B. Strongyloides stercoralis

49
Q

In a pediatric patient, the recommended clinical specimens for recovery of Enterobius vermicularis are the:
A. Stool specimens
B. Sigmoidoscopy scrapings
C. Duodenal aspirates
D. Series of cellophane tape preparations

A

D. Series of cellophane tape preparations

50
Q

Eosinophilic meningoencephalitis is a form of larva migrans, causing fever, headache, stiff neck, and increased cells in the spinal fluid. It is caused by:
A. Necator americanus
B. Angiostrongylus cantonensis
C. Ancylostoma braziliense
D. Strongyloides stercoralis

A

B. Angiostrongylus cantonensis

51
Q

“Cultures of parasites are different from bacterial cultures; no quality control is needed.” This statement is:
A. True, if two tubes of media are set up for each patient
B. True, if the media are checked every 24 hours
C. False, unless two different types of media are used
D. False, and organism and media controls need to be set up

A

D. False, and organism and media controls need to be set up

52
Q

Protozoan cysts were seen in a concentration sediment and tentatively identified as Entamoeba coli. However, the organisms were barely visible on the permanent stained smear because:
A. The organisms were actually not present in the concentration sediment
B. There were too few cysts to allow identification on the stained smear
C. Entamoeba coli cysts were present but poorly fixed due to the thick cyst wall
D. The concentrate and permanent stained smear were not from the same patient

A

C. Entamoeba coli cysts were present but poorly fixed due to the thick cyst wall

53
Q

When humans have hydatid disease, the causative agent and host classification are:
A. Echinococcus granulosus—accidental intermediate host
B. Echinococcus granulosus—definitive host
C. Taenia solium—accidental intermediate host
D. Taenia solium—definitive host

A

A. Echinococcus granulosus—accidental intermediate host

54
Q

A 45-year-old hunter developed fever, myalgia, and periorbital edema. He has a history of bear meat consumption. The most likely causative agent is:
A. Toxoplasma gondii
B. Taenia solium
C. Hymenolepis nana
D. Trichinella spiralis

A

D. Trichinella spiralis

55
Q

In a condition resulting from the accidental ingestion of eggs, the human becomes the intermediate host, rather than the definitive host. The correct answer is:
A. Trichinosis
B. Cysticercosis
C. Ascariasis
D. Strongyloidiasis

A

B. Cysticercosis

56
Q

transplant recipient on immunosuppressive drugs developed increasing diarrhea. The most likely combination of disease and diagnostic procedure is:
A. Trichinosis and trichrome staining
B. Microsporidiosis and modified trichrome staining
C. Toxoplasmosis and Gram staining
D. Paragonimiasis and wet preparation

A

B. Microsporidiosis and modified trichrome staining

57
Q

After returning from a 2-year stay in India, a patient has eosinophilia, an enlarged left spermatic cord, and bilateral inguinal lymphadenopathy. The most likely clinical specimen and organism match is:
A. Thin blood films and Leishmania
B. Urine and concentration for Trichomonas vaginalis
C. Thin blood films and Babesia
D. Thick blood films and microfilariae

A

D. Thick blood films and microfilariae

58
Q

Patients with severe diarrhea should use “enteric precautions” to prevent nosocomial infections with:
A. Giardia lamblia (G. intestinalis, G. duodenalis)
B. Ascaris lumbricoides
C. Cryptosporidium spp.
D. Cystoisospora belli

A

C. Cryptosporidium spp.

59
Q

A 60-year-old Brazilian patient with cardiac irregularities and congestive heart failure suddenly dies. Examination of the myocardium revealed numerous amastigotes, an indication that the cause of death was most likely:
A. Leishmaniasis with Leishmania donovani
B. Leishmaniasis with Leishmania braziliense
C. Trypanosomiasis with Trypanosoma gambiense
D. Trypanosomiasis with Trypanosoma cruzi

A

D. Trypanosomiasis with Trypanosoma cruzi

60
Q

When analysis of blood smears for malaria are requested, what patient information should be obtained?
A. Diet, age, gender
B. Age, antimalarial medication, gender
C. Travel history, antimalarial medication, date of return to United States
D. Fever patterns, travel history, diet

A

C. Travel history, antimalarial medication, date of return to United States

61
Q

In an outbreak of diarrheal disease traced to a municipal water supply, the most likely causative agent is:
A. Cryptosporidium spp.
B. Cystoisospora belli
C. Entamoeba histolytica
D. Dientamoeba fragilis

A

A. Cryptosporidium spp.

62
Q

Within the United States, sporadic mini-outbreaks of diarrheal disease have been associated with the ingestion of strawberries, raspberries, fresh basil, mesclun (baby lettuce leaves), and snow peas. The most likely causative agent is:
A. Dientamoeba fragilis
B. Cyclospora cayetanensis
C. Schistosoma mansoni
D. Cystoisospora belli

A

B. Cyclospora cayetanensis

63
Q

Which of the following statements is true regarding onchocerciasis?
A. The adult worm is present in blood
B. The microfilariae are in blood during the late evening hours
C. The diagnostic test of choice is the skin snip
D. The parasite resides in the deep lymphatics

A

C. The diagnostic test of choice is the skin snip

64
Q

The most prevalent helminth to infect humans is:
A. Enterobius vermicularis, the pinworm
B. Ascaris lumbricoides, the large intestinal roundworm
C. Taenia saginata, the beef tapeworm
D. Schistosoma mansoni, one of the blood flukes

A

A. Enterobius vermicularis, the pinworm

65
Q

A helminth egg is described as having terminal polar plugs. The most likely helminth is:
A. Hookworm
B. Trichuris trichiura
C. Fasciola hepatica
D. Diphyllobothrium latum

A

B. Trichuris trichiura

66
Q

Ingestion of which of the following eggs will result in infection?
A. Strongyloides stercoralis
B. Schistosoma japonicum
C. Toxocara canis
D. Opisthorchis sinensis

A

C. Toxocara canis

67
Q

Plasmodium vivax and Plasmodium ovale are similar because they:
A. Exhibit Schüffner dots and have a true relapse in the life cycle
B. Have no malarial pigment and multiple rings
C. Commonly have appliqué forms in the red cells
D. Have true stippling, do not have a relapse stage, and infect old red cells

A

A. Exhibit Schüffner dots and have a true relapse in the life cycle

68
Q

The term internal autoinfection can be associated with the following parasites:
A. Cryptosporidium spp. and Giardia lamblia (G. intestinalis, G. duodenalis)
B. Cystoisospora belli and Strongyloides stercoralis
C. Cryptosporidium spp. and Strongyloides stercoralis
D. Giardia lamblia (G. intestinalis, G. duodenalis) and Cystoisospora belli

A

C. Cryptosporidium spp. and Strongyloides stercoralis

69
Q

Microsporidia have been identified as causing severe diarrhea, disseminated disease in other body sites, and ocular infections. Routes of infection have been identified as:
A. Ingestion
B. Inhalation
C. Direct contamination from the environment
D. Ingestion, inhalation, and direct contamination from the environment

A

D. Ingestion, inhalation, and direct contamination from the environment

70
Q

An immunocompromised patient continues to have diarrhea after repeated ova and parasites (O&P) examinations (sedimentation concentration, trichrome permanent stained smear) were reported as negative; organisms that might be responsible for the diarrhea include:
A. Cryptosporidium spp., Giardia lamblia (G. intestinalis, G. duodenalis), and Cystoisospora belli
B. Giardia lamblia (G. intestinalis, G. duodenalis), microsporidia, and Endolimax nana
C. Taenia solium and Endolimax nana
D. Cryptosporidium spp. and microsporidia

A

D. Cryptosporidium spp. and microsporidia

71
Q

Confirmation of an infection with microsporidia can be achieved by seeing:
A. The oocyst wall
B. Sporozoites within the oocyst
C. Evidence of the polar tubule
D. Organisms stained with modified acid-fast stains

A
72
Q

Early ring forms of the fifth human malaria, Plasmodium knowlesi, resemble those of:
A. Plasmodium vivax
B. Plasmodium ovale
C. Plasmodium malariae
D. Plasmodium falciparum

A

D. Plasmodium falciparum

73
Q

Parasite stages that are immediately infective for humans on passage from the gastrointestinal tract include:
A. Schistosoma spp. eggs
B. Toxoplasma gondii bradyzoites
C. Ascaris lumbricoides eggs
D. Cryptosporidium spp. oocysts

A

D. Cryptosporidium spp. oocysts

74
Q

Older developing stages (trophozoites, schizonts) of the fifth human malaria, Plasmodium knowlesi, resemble those of:
A. Plasmodium vivax
B. Plasmodium ovale
C. Plasmodium malariae
D. Plasmodium falciparum

A

C. Plasmodium malariae

75
Q

Autofluorescence requires no stain and is recommended for the presumptive identification of:
A. Entamoeba histolytica cysts
B. Toxoplasma gondii tachyzoites
C. Dientamoeba fragilis trophozoites
D. Cyclospora cayetanensis oocysts

A

D. Cyclospora cayetanensis oocysts

76
Q

Key characteristics of infection with Plasmodium knowlesi include:
A. Rapid erythrocyte cycle (24 hours), will infect all ages of RBCs, and can cause serious disease
B. Erythrocytic cycle limited to young RBCs and causes a relatively benign disease
C. The possibility of a true relapse from the liver, infection in older RBCs, and causes serious disease
D. Extended life cycle (72 hours), will infect all ages of RBCs, and disease is similar to that caused by Plasmodium ovale.

A

A. Rapid erythrocyte cycle (24 hours), will infect all ages of RBCs, and can cause serious disease

77
Q

Microsporidial infections can be confirmed by using:
A. Light microscopy and modified trichrome staining
B. Phase contrast microscopy and routine trichrome staining
C. Electron microscopy and modified acid-fast staining
D. Fluorescence microscopy and hematoxylin staining

A

A. Light microscopy and modified trichrome staining

78
Q

Although the pathogenicity of Blastocystis spp. remains controversial, newer information suggests that:
A. Most organisms are misdiagnosed as artifacts
B. Approximately 10 subtypes/strains are included in the name, some of which are pathogenic and some are nonpathogenic
C. The immune status of the host is solely responsible for symptomatic infections
D. The number of organisms present determines pathogenicity

A

B. Approximately 10 subtypes/strains are included in the name, some of which are pathogenic and some are nonpathogenic

79
Q

Potential problems using EDTA anticoagulant and holding the blood too long prior to preparation of thick and thin blood films include:
A. Changes in parasite morphology, loss of organisms within several hours, and poor staining
B. Loss of Schüffner dots, poor adherence of the blood to the glass slide, and parasites beginning the vector cycle within the tube of blood
C. None of the above
D. All of the above

A

D. All of the above

80
Q

Key characteristics of the thick film include:
A. The ability to see the parasite within the RBCs
B. The ability to identify the parasites to the species level
C. The examination of less blood than the thin blood film
D. The necessity to lake the RBCs during or prior to staining

A

D. The necessity to lake the RBCs during or prior to staining

*Microbiology Extern (12 decks)

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