Mycology/Parasitology Questions
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
Diphyllobothrium latum and Paragonimus westermani
The adult tapeworm of Echinococcus granulosus is found in the intestine of: A. Dogs B. Sheep C. Humans D. Cattle
Dogs
Parasitic organisms that are most often transmitted sexually include: A. Entamoeba gingivalis B. Dientamoeba fragilis C. Trichomonas vaginalis D. Diphyllobothrium latum
Trichomonas vaginalis
Arthroconidia production is used to differentiate which two yeast isolates? A. Candida albicans and Candida dubliniensis B. Trichosporon cutaneum and Cryptococcus neoformans C. Candida albicans and Candida tropicalis D. Saccharomyces cerevisiae and Candida glabrata
Trichosporon cutaneum and Cryptococcus neoformans
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's stain
Trichrome-stained smear
All of the following are examples of appropriate specimens for the recovery of fungi except: A. Tissue biopsy B. CSF C. Aspirate of exudate D. Swab
Swab
The Hair Baiting Test is used to differentiate which two species of Trichophyton that produce red colonies on Sabouraud agar plates? A. T. mentagrophytes and T. rubrum B. T. tonsurans and T. schoenleinii C. T. tonsurans and T. violaceum D. T. verrucosum and T. rubrum
T. mentagrophytes and T. rubrum
Which Trichophyton species causes the favus type of tinea capitis seen in the Scandinavian countries and in the Appalachian region of the United States? A. T. verrucosum B. T. violaceum C. T. tonsurans D. T. schoenleinii
T. schoenleinii
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
Cryptosporidium spp.
Patients with severe diarrhea should use "enteric precautions" to prevent nosocomial infections with: A. Giardia lamblia B. Ascaris lumbricoides C. Cryptosporidium spp. D. Cystoisospora belli
Cryptosporidium spp.
The term internal autoinfection can be associated with the following parasites: A. Cryptosporidium spp. and Giardia lamblia B. Cystoisospora belli and Strongyloides stercoralis C. Cryptosporidium spp. and Strongyloides stercoralis D. Giardia lamblia and Cystoisospora belli
Cryptosporidium spp. and Strongyloides stercoralis
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, and Cystoisospora belli B. Giardia lamblia, microsporidia, and Endolimax nana C. Taenia solium and Endolimax nana D. Cryptosporidium spp. and microsporidia
Cryptosporidium spp. and microsporidia
Parasite stages that are immediately infective for humans on passage from the gastrointestinal tract include: A. Schistosoma spp. eggs B. Toxoplasma gondii bradyzoites C. Giardia lamblia trophozoites D. Cryptosporidium spp. oocysts
Cryptosporidium spp. oocysts
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
Cyclospora cayetanensis
Autofluorescence requires no stain and is recommended for the identification of: A. Entamoeba histolytica cysts B. Toxoplasma gondii tachyzoites C. Dientamoeba fragilis trophozoites D. Cyclospora cayetanensis oocysts
Cyclospora cayetanensis oocysts
In a condition resulting from the accidental ingestion of eggs, the human becomes the intermediate rather than the definitive host. The correct answer is: A. Trichinosis B. Cysticercosis C. Ascariasis D. Strongyloidiasis
Cysticercosis
A Gram stain 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/E. dispar C. Entamoeba gingivalis D. Entamoeba polecki
Entamoeba gingivalis
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
Enterobiasis—dysentery
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
Enterobius vermicularis, the pinworm
Confirmation of an infection with microsporidia can be achieved by seeing: A. The oocyst wall B. Sporozoites within the spore C. Evidence of the polar tubule D. Organisms stained with modified acid-fast stains
Evidence of the polar tubule
Plasmodium vivax and Plasmodium ovale are similar because they: A. Exhibit Schüffner's 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
Exhibit Schüffner's dots and have a true relapse in the life cycle
A hyaline mold recovered from a patient with AIDS produced rose-colored colonies with lavender centers on Sabouraud dextrose agar. Microscopic examination showed multiseptate macroconidia appearing as sickles or canoes. What is the most likely identification? A. Fusarium spp. B. Wangiella spp. C. Exophiala spp. D. Phialophora spp.
Fusarium spp.
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
Ingestion of raw freshwater fish
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
Ingestion, inhalation, and direct contamination
The incorrect match between method and method objective is: A. Direct wet examination—detection of organism motility B. Knott's concentration—the recovery of operculated helminth eggs C. Baermann's concentration—the recovery of Strongyloides D. Permanent stained fecal smear—confirmation of protozoa
Knott's concentration—the recovery of operculated helminth eggs
Microsporidial infections can be confirmed using: A. Light microscopy and modified trichrome stains B. Phase contrast microscopy and routine trichrome stains C. Electron microscopy and modified acid-fast stains D. Fluorescence microscopy and hematoxylin stains
Light microscopy and modified trichrome stains
A transplant patient on immunosuppressive drugs developed increasing diarrhea. The most likely combination of disease and diagnostic procedure is: A. Trichinosis and trichrome stain B. Microsporidiosis and modified trichrome stain C. Toxoplasmosis and Gram stain D. Paragonimiasis and wet preparation
Microsporidiosis and modified trichrome stain
Which Microsporum species causes an epidemic form of tinea capitis in children? A. Microsporum canis B. Microsporum audouinii C. Microsporum gypseum D. All of these options
Microsporum audouinii
The yeast form of which dimorphic mold shows a large parent yeast cell surrounded by smaller budding yeast cells? A. Paracoccidioides brasiliensis B. Sporothrix schenckii C. Coccidioides immitis D. Histoplasma capsulatum
Paracoccidioides brasiliensis
Which of the following yeast enzymes is detected using birdseed (niger seed) agar? A. Phenol oxidase B. Catalase C. Urease D. Nitrate reductase
Phenol oxidase
Early ring stages of the fifth human malaria, Plasmodium knowlesi, resemble those of: A. Plasmodium malariae B. Plasmodium ovale C. Plasmodium falciparum D. Plasmodium vivax
Plasmodium falciparum
Older developing stages (trophs, schizonts) of the fifth human malaria, Plasmodium knowlesi, resemble those of: A. Plasmodium malariae B. Plasmodium ovale C. Plasmodium falciparum D. Plasmodium vivax
Plasmodium malariae
Material from a fungus-ball infection produced colonies with a green surface on Sabouraud agar in 5 days at 30°C. Microscopic examination showed club-shaped vesicles with sporulation only from the top half of the vesicle. This hyaline mold is most probably which Aspergillus spp.? A. A. niger B. A. fumigatus C. A. flavus D. A. terreus
A. fumigatus
An isolate from CSF growing on cornmeal agar produces the following structures: Blastoconidia = + Pseudohyphae = Neg Chlamydospores = Neg Arthroconidia= Neg Which tests should be performed next? A. Birdseed agar and urease B. Germ tube and glucose C. India ink and germ tube D. All of these options
Birdseed agar and urease
There are few procedures considered STAT in parasitology. The most obvious situation would be: A. Ova and parasite examination for giardiasis B. Baermann's concentration for strongyloidiasis C. Blood films for malaria D. Culture of amoebic keratitis
Blood films for malaria
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. Neither A nor B D. Both A and B
Both A and B
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
Schistosoma haematobium eggs
Which of the following is a key characteristic of the thick blood film? 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
The necessity to lake the RBCs during or prior to staining
Ingestion of which of the following eggs will result in infection? A. Strongyloides stercoralis B. Schistosoma japonicum C. Toxocara canis D. Opisthorchis sinensis
Toxocara canis
Visceral larva migrans is associated with which of the following organisms? A. Toxocara—serology B. Onchocerca—skin snips C. Dracunculus—skin biopsy D. Angiostrongylus—CSF examination
Toxocara—serology
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
Protozoan cysts and helminth eggs
A bone marrow sample obtained from an immunocompromised patient revealed small intracellular cells using a Wright's stain preparation. Growth on Sabouraud-dextrose agar plates of a mold phase at 25°C and a yeast phase at 37°C designates the organism as dimorphic. The mold phase produced thick, spherical tuberculated macroconidia. What is the most likely identification? A. Histoplasma capsulatum B. Sepedonium spp. C. Sporothrix schenckii D. Coccidioides immitis
Histoplasma capsulatum
A thermally dimorphic fungus shows a filamentous mold form with tuberculate macroconidia at room temperature, and a yeast form above 35°C. Which organism best fits this description? A. Histoplasma capsulatum B. Paracoccidioides brasiliensis C. Candida albicans D. Coccidioides immitis
Histoplasma capsulatum
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 large glycogen vacuole
A rapidly growing nonseptate mold produced colonies with a gray surface resembling cotton candy that covered the entire plate. Microscopic examination revealed sporangiophores arising between, not opposite, the rhizoids and producing pear-shaped sporangia. What is the most likely identification? A. Absidia spp. B. Penicillium spp. C. Rhizopus spp. D. Aspergillus spp.
Absidia spp.
Cornmeal agar with Tween 80 is used to identify which characteristic of an unknown yeast isolate? A. Hyphae (true and pseudo) B. Blastoconidia and arthroconidia C. Chlamydospores D. All of these options
All of these options
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's dots, poor adherence of the blood to the glass slide, and parasites beginning the vector cycle within the tube of blood C. Neither A nor B D. All of these options
All of these options
Which of the following structures is invaded by the genus Trichophyton? A. Hair B. Nails C. Skin D. All of these options
All of these options
A blood agar plate inoculated with sputum from a patient with diabetes mellitus grew very few bacterial flora and a predominance of yeast. Given the following results, what is the most likely identification of the yeast isolate? CORNMEAL TWEEN 80 AGAR Germ tube = Neg Pseudohyphae = + Arthroconidia = Neg Blastoconidia = + (arranged along pseudohyphae) Chlamydospores = Neg A. Candida tropicalis B. Candida kefyr (pseudotropicalis) C. Trichosporon cutaneum D. Geotrichum candidum
Candida tropicalis
An isolate produced a constriction that was interpreted as a positive germ tube, but Candida albicans was ruled out when confirmatory tests were performed. Which of the following fungi is the most likely identification? A. Candida tropicalis B. Cryptococcus neoformans C. Candida glabrata D. Rhodotorula rubra
Candida tropicalis
An Entamoeba histolytica trophozoite has the following characteristics: A. Central 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
Central karyosome in the nucleus, ingested RBCs, and clear pseudopodia
A mold that produces colonies with a dark brown, green-black, or black appearance of both the surface and reverse side is classified as a: A. Dematiaceous mold B. Dermatophyte C. Hyaline mold D. Dimorphic fungus
Dematiaceous mold
Cutaneous disease involving skin, hair, and nails usually indicates an infection with a: A. Dimorphic fungus B. Dermatophyte C. Zygomycetes D. Candida species
Dermatophyte
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 concentrate sediment B. There were too few cysts to allow identification on the stained smear C. E. coli cysts were present but poorly fixed D. The concentrate and permanent stained smear were not from the same patient
E. coli cysts were present but poorly fixed
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
Echinococcus granulosus—accidental intermediate host
"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
False, and organism and media controls need to be set up
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
Hymenolepis nana
A 12-year-old girl is brought to the emergency department with meningitis and a history of swimming in a warm-water spring. Motile amoebae that measure 10 μ in size are seen in the CSF and are most likely: A. Iodamoeba bütschlii trophozoites B. Endolimax nana trophozoites C. Dientamoeba fragilis trophozoites D. Naegleria fowleri trophozoites
Naegleria fowleri trophozoites
Although the pathogenicity of Blastocystis hominis remains controversial, newer information suggests that: A. Most organisms are misdiagnosed as artifacts B. Numerous strains/species 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
Numerous strains/species are included in the name, some of which are pathogenic and some are nonpathogenic
Key characteristics of infection with Plasmodium knowlesi include: A. Rapid erythrocytic cycle (24 hr), 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 hr), will infect all ages of RBCs, and disease is similar to that caused by P. ovale
Rapid erythrocytic cycle (24 hr), will infect all ages of RBCs, and can cause serious disease
What is the most common cause of mucormycosis infection in humans? A. Penicillium spp. B. Candida albicans C. Scopulariopsis spp. D. Rhizopus spp.
Rhizopus spp.
A germ tube-negative, pink yeast isolate was recovered from the respiratory secretions and urine of a patient with AIDS. Given the following results, what is the most likely identification? CORNMEAL TWEEN 80 AGAR Blastoconidia = + Pseudohyphae = Neg Arthroconidia= Neg Urease = + A. Candida albicans B. Rhodotorula spp. C. Cryptococcus spp. D. Trichosporon spp.
Rhodotorula spp.
Ascospores are formed by which yeast isolate? A. Saccharomyces cerevisiae B. Candida albicans C. Cryptococcus neoformans D. All of these options
Saccharomyces cerevisiae
The yeast form of which dimorphic fungus appears as oval or elongated cigar shapes? A. Coccidioides immitis B. Sporothrix schenckii C. Histoplasma capsulatum D. Blastomyces dermatitidis
Sporothrix schenckii
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
Strongyloides stercoralis
Which of the following statements is true regarding onchocerciasis? A. The adult worm is present in the blood B. The microfilariae are in the blood during the late evening hours C. The diagnostic test of choice is the skin snip D. The parasite resides in the deep lymphatics
The diagnostic test of choice is the skin snip
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's stain method
The use of non-nutrient agar cultures seeded with Escherichia coli
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—Leishmania B. Urine—concentration for Trichomonas vaginalis C. Thin blood films—Babesia D. Thick blood films—microfilariae
Thick blood films—microfilariae
When malaria smears are requested, what patient information should be obtained? A. Diet, age, sex B. Age, antimalarial medication, sex C. Travel history, antimalarial medication, date of return to United States D. Fever patterns, travel history, diet
Travel history, antimalarial medication, date of return to United States
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
Trichinella spiralis
An organism cultured from the skin produces colonies displaying a cherry-red color on Sabouraud dextrose agar after 3-4 weeks and teardrop-shaped microconidia along the sides of the hyphae. The most likely identification is: A. Trichophyton rubrum B. Trichophyton tonsurans C. Trichophyton schoenleinii D. Trichophyton violaceum
Trichophyton rubrum
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
Trichuris trichiura
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
Trypanosomiasis with Trypanosoma cruzi
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
Use of contaminated lens care solutions
Dimorphic molds are found in infected tissue in which form? A. Mold phase B. Yeast phase C. Encapsulated D. Latent
Yeast phase
Which group of molds can be ruled out when septate hyphae are observed in a culture? A. Dematiaceous B. Zygomycetes C. Dermatophytes D. Dimorphic molds
Zygomycetes
Which Aspergillus species, recovered from sputum or bronchial mucus, is the most common cause of pulmonary aspergillosis? A. A. niger B. A. flavus C. A. fumigatus D. All of these options
A. fumigatus
Which parasite causes eosinophilic meningoencephalitis, a form of larva migrans causing fever, headache, stiff neck, and increased cells in the spinal fluid? A. Necator americanus B. Angiostrongylus cantonensis C. Ancylostoma braziliense D. Strongyloides stercoralis
Angiostrongylus cantonensis
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
Ascaris lumbricoides—ascariasis
A rapidly growing hyaline mold began as a white colony but soon developed a black "pepper" effect on the agar surface. The older colony produced a black matte, making it resemble a dematiaceous mold. What is the most likely identification? A. Penicillium notatum B. Aspergillus niger C. Paecilomyces spp. D. Scopulariopsis spp
Aspergillus niger
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—serology D. Balantidium coli—common within the United States
Balantidium coli—common within the United States
Chlamydospore production is demonstrated by which Candida species? A. C. glabrata B. C. krusei C. C. albicans D. C. tropicalis
C. albicans
Which of the following yeasts is characteristically positive for germ tube production? A. Candida tropicalis B. Candida kefyr (pseudotropicalis) C. Cryptococcus neoformans D. Candida albicans
Candida albicans
SITUATION: After a vacation to the Southwestern United States, a midwesterner complained of flulike symptoms with fever, chills, nonproductive cough, and chest pain. Microscopic exam of sputum, cleared with KOH, revealed large, thick-walled spherules containing endospores. Upon culture, the mold phase showed septate hyphae and alternating barrel-shaped arthroconidia. Which organism is most likely the cause of this pneumonia? A. Coccidioides immitis B. Histoplasma capsulatum C. Paracoccidioides brasiliensis D. Penicillium marneffei
Coccidioides immitis
The mycelial form of which dimorphic mold produces thick-walled, rectangular, or barrel-shaped alternate arthroconidia? A. Coccidioides immitis B. Sporothrix schenckii C. Histoplasma capsulatum D. Blastomyces dermatitidis
Coccidioides immitis
Upon direct examination of a sputum specimen, several spherules were noted that contained endospores. Growth on Sabouraud-dextrose agar showed aerial mycelial elements. The septate hyphae produced barrel-shaped arthroconidia. What is the most likely identification? A. Penicillium marneffei B. Scopulariopsis spp. C. Cryptococcus neoformans D. Coccidioides immitis
Coccidioides immitis
An India ink test was performed on CSF from an HIV-infected male patient. Many encapsulated yeast cells were seen in the centrifuged sample. Further testing revealed a positive urease test and growth of brown colonies on niger-seed agar. The diagnosis of meningitis was caused by which yeast? A. Candida albicans B. Cryptococcus neoformans C. Cryptococcus laurentii D. Candida tropicalis
Cryptococcus neoformans
The urease test, niger seed agar test, and the germ tube test are all used for the presumptive identification of: A. Rhodotorula rubra B. Cryptococcus neoformans C. Trichosporon cutaneum D. Candida albicans
Cryptococcus neoformans
The India ink stain is used as a presumptive test for the presence of which organism? A. Aspergillus niger in blood B. Cryptococcus neoformans in CSF C. Histoplasma capsulatum in CSF D. Candida albicans in blood or body fluids
Cryptococcus neoformans in CSF
Which of the following yeasts produces only blastoconidia on cornmeal Tween 80 agar? A. Candida spp. B. Trichosporon spp. C. Geotrichum spp. D. Cryptococcus spp.
Cryptococcus spp.
An operculated cestode egg that can be recovered from human feces is: A. Clonorchis sinensis B. Diphyllobothrium latum C. Paragonimus westermani D. Dipylidium caninum
Diphyllobothrium latum
The incorrect match between organism and the appropriate diagnostic procedure is: A. Onchocerca volvulus—examination of skin snips B. Cryptosporidium—modified acid-fast stain C. Echinococcus granulosus—routine ova and parasite examination D. Schistosoma haematobium—examination of urine sediment
Echinococcus granulosus—routine ova and parasite examination
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 these options
Either the definitive or the intermediate host
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
Eosinophils
Microscopic examination of a fungus cultured from a patient with athlete's foot showed large, smooth-walled, club-shaped macroconidia appearing singly or in clusters of two to three from the tips of short conidiophores. The colonies did not produce microconidia. What is the most likely identification? A. Trichophyton spp. B. Alternaria spp. C. Epidermophyton spp. D. Microsporum spp.
Epidermophyton spp.
Which specimen is the least likely to provide recovery of Trichomonas vaginalis? A. Urine B. Urethral discharge C. Vaginal discharge D. Feces
Feces
Carbohydrate assimilation tests are used for the identification of yeast isolates by inoculating media: A. Free of carbohydrates B. Free of niger seed C. Containing carbohydrates D. Containing yeast extract
Free of carbohydrates
What is the first step to be performed in the identification of an unknown yeast isolate? A. Gram stain smear B. India ink stain C. Catalase test D. Germ tube test
Germ Tube Test
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 D. Balantidium coli
Giardia lamblia
Fecal immunoassays have become more commonly used to diagnose infections with: A. Endolimax nana and Blastocystis hominis B. Giardia lamblia and Cryptosporidium spp. C. Ascaris lumbricoides and Trichuris trichiura D. Strongyloides stercoralis and Trichomonas vaginalis
Giardia lamblia and Cryptosporidium spp.
Organisms that should be considered in a waterborne outbreak of diarrheal disease include: A. Giardia lamblia and Cryptosporidium spp. B. Endolimax nana and Entamoeba histolytica C. Blastocystis hominis and Trichomonas vaginalis D. Toxoplasma gondii and Schistosoma mansoni
Giardia lamblia and Cryptosporidium spp.
Organisms that should be considered in a nursery school outbreak of diarrhea include: A. Endolimax nana, Giardia lamblia, and Entamoeba coli B. Giardia lamblia, Dientamoeba fragilis, and Cryptosporidium spp. C. Cryptosporidium spp., Trichomonas vaginalis, and Entamoeba coli D. Pentatrichomonas hominis, Dientamoeba fragilis, and Endolimax nana
Giardia lamblia, Dientamoeba fragilis, and Cryptosporidium spp.
The incorrect match between organism and characteristic is: A. Chilomastix mesnili—Shepherd's crook and lemon shape B. Plasmodium malariae—"band troph" C. Hymenolepis nana—striated shell D. Wuchereria bancrofti—sheathed microfilariae
Hymenolepis nana—striated shell
The microsporidia are protozoans (now classified with the fungi) that have been implicated in human disease primarily in: A. Immunocompromised patients B. Pediatric patients under the age of 5 years C. Adult patients with congenital immunodeficiencies D. Patients who have been traveling in the tropics
Immunocompromised patients
What is the specimen of choice for the initial diagnosis of Pneumocystis jirovecii (carinii) in an immunocompromised patient, such as someone with AIDS? A. Induced sputum B. Open-thorax lung biopsy C. CSF D. Urine
Induced sputum
Tinea versicolor is a skin infection caused by: A. Malassezia furfur B. Trichophyton rubrum C. Trichophyton schoenleinii D. Microsporum gypseum
Malassezia furfur
Oocysts of Cryptosporidium spp. can be detected in stool specimens using: A. Modified Ziehl-Neelsen acid-fast stain B. Gram stain C. Methenamine silver stain D. Trichrome stain
Modified Ziehl-Neelsen acid-fast stain
The incorrect match between symptoms and disease is: A. Dysentery—amebiasis B. Malabsorption syndrome—giardiasis C. Cardiac involvement—chronic Chagas disease D. Myalgias—trichuriasis
Myalgias—trichuriasis
Yeast recovered from the urine of a catheterized patient receiving chemotherapy for cancer gave the following results: CORNMEAL TWEEN 80 AGAR Germ tube = + Blastoconidia = + Pseudohyphae = + Arthroconidia= Neg Chlamydospores= + What further testing is necessary? A. Carbohydrate assimilation and urease B. Urease and niger seed C. Nitrate reductase and carbohydrate fermentation D. No further testing is needed for identification
No further testing is needed for identification
Which microfilariae are usually not found circulating in the peripheral blood? A. Brugia malayi B. Wuchereria bancrofti C. Onchocerca volvulus D. Loa loa
Onchocerca volvulus
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 variable D. Sporozoites that are hematoxylin positive
Oocysts that are modified acid-fast variable
The examination of sputum may be necessary to diagnose infection with: A. Paragonimus westermani B. Trichinella spiralis C. Wuchereria bancrofti D. Fasciola hepatica
Paragonimus westermani
A bone marrow specimen was obtained from an immunocompromised patient who tested positive for HIV. The organism grew rapidly at 3 days showing a mold form (at 25°C), displaying conidiophores with four to five terminal metulae with each having four to six phialides. The conidia at the end of the phialides were oval and in short chains. They appear as a fan or broom when viewing under 10× and 40×. At 37°C, the yeast form grew more slowly, showing conidia that formed hyphal elements breaking at the septa to produce oval arthroconidia. This thermodimorphic mold is most likely: A. Paecilomyces spp. B. Penicillium marneffei C. Rhizomucor spp. D. Aspergillus fumigatus
Penicillium marneffei
Which dematiaceous mold forms flask-shaped phialides, each with a flask-shaped collarette? A. Phialophora spp. B. Exophiala spp. C. Wangiella spp. D. All of these options
Phialophora spp.
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
Plasmodium falciparum
Babesia 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. Microsporidial spores
Plasmodium falciparum rings
A lung biopsy obtained from an immunocompromised patient showed many "cup-shaped" cysts (gray to black) in a foamy exudate (green background) using Gomori methenamine silver (GMS) stain. The organism cannot be cultured because it does not grow on routine culture media for molds. The patient was diagnosed with pneumonia that resisted antibiotic treatment. The most likely identification is? A. Pneumocystis jirovecci (carinii) B. Histoplasma capsulatum C. Sporothrix schenckii D. Scopulariopsis spp.
Pneumocystis jirovecci (carinii)
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 C. Epithelial cells D. Eosinophils
Polymorphonuclear leukocytes
Blastoconidia are the beginning of which structures? A. Arthroconidia B. Germ tubes C. Pseudohyphae D. True hyphae
Pseudohyphae
The incorrect match between organism and characteristic is: A. Dientamoeba fragilis—tetrad karyosome in the nucleus B. Toxoplasma gondii—diagnostic serology C. Echinococcus granulosus—daughter cysts D. Schistosoma mansoni—egg with terminal spine
Schistosoma mansoni—egg with terminal spine
The miracidial hatching test helps to demonstrate the viability of eggs of: A. Taenia species B. Schistosoma species C. Hookworm species D. Opisthorchis species
Schistosoma species
The mycelial form of Histoplasma capsulatum seen on agar resembles: A. Sepedonium spp. B. Penicillium spp. C. Sporothrix spp. D. Coccidioides spp.
Sepedonium spp.
In a pediatric patient, the recommended clinical specimen for recovery of Enterobius vermicularis is the: A. Stool specimen B. Sigmoidoscopy scrapings C. Duodenal aspirates D. Series of Scotch tape preparations
Series of Scotch tape preparations
A transplant patient is suspected of having invasive aspergillosis on the basis of clinical and radiological findings. Which specimen is best for the initial identification of aspergillosis by soluble antigen testing? A. Blood culture B. Lung biopsy C. Serum or urine D. Sputum
Serum or urine
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
Short buccal capsule and large genital primordium
For which clinical specimens is the KOH direct mount technique for examination of fungal elements used? A. Skin B. CSF C. Blood D. Bone marrow
Skin
Eating poorly cooked 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
Taenia solium and Trichinella spiralis
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 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
The decolorizer is weaker than acid alcohol used for AFB decolorizing
Primary infections with the microsporidia may originate in: A. The lung B. The nervous system C. The gastrointestinal tract D. Mucocutaneous lesions
The gastrointestinal tract
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—ingestion of water contaminated with cysts C. Hookworm—skin penetration of larvae from soil D. Toxoplasma gondii—ingestion of raw or rare meats
Trypanosoma brucei rhodesiense—bite of sand fleas
