Microbiology - Parasitology

1. Microscopic examination of peripheral blood may be diagnostic for infection with each of the following parasites EXCEPT:

A. Plasmodium vivax
B. Trypanosoma cruzi
C. Trichinella spiralis
D. Wuchereria bancrofti

C

2. In hookworm cases where progressive anemia is present, what additional test procedure should be performed to determine infection in stool specimens?

A. Permanently stained smear
B. Modified acid-fast stain
C. Concentration technique
D. Wet mount preparation

C

3. All of the organisms are listed with a common site of recovery for that parasite, EXCEPT:

A. Giardia lamblia - duodenal contents
B. Trichuris trichuria - stool
C. Plasmodium falciperum - ocular secretions
D. Paragonimus westermanni - sputum

C

4. The specimen of choice for the recovery of Entamoeba hartmanni is:

A. CSF
B. Genital discharge
C. Stool
D. Urine

C

5. Which of the following is the correct order when performing a permanent stained smear of a stool specimen?

A. 100% ethanol; 70% ethanol/D'Antoni's iodine; 70% ethanol; Trichrome stain; 90% ethanol; Xylene
B. 90% ethanol; 70% ethanol/D'Antoni's iodine; 70% ethanol; Trichrome stain; 100% ethanol; Xylene
C. 70% ethanol/D'Antoni's iodine; 70% ethanol; Trichrome stain; 90% ethanol;100% ethanol; Xylene
D. 70% ethanol/D'Antoni's iodine; 100% ethanol; 90% ethanol; Trichrome stain; 70% ethanol; Xylene

C

6. Stool is the specimen of choice for the recovery of which of the following parasites?

A. Trichinella spiralis
B. Diphyllobothrium latum
C. Plasmodium falciparum
D. Schistosoma haematobium

B

7. Which of the following adult parasites are found in the lungs and the eggs are most commonly recovered in sputum samples?

A. Fasciola spp.
B. Clonorchis sinensis
C. Opisthorchis spp.
D. Paragonimus spp.

D

8. At an outpatient clinic, a patient comes in with an order for stool ova and parasites (O & P). How should this specimen be collected and transported for best test results?

A. The specimen should be collected in a sterile container and transported to the laboratory by the end of the shift.
B. A small sample of the specimen should be applied to the two small windows of the Guaiac smear test card and sent to the laboratory immediately.
C. The specimen should be immediately placed in recipients containing polyvinyl alcohol (PVA) or formalin and transported to the laboratory.
D. A rectal swab sent immediately to the laboratory will produce the most reliable test results.

C

9. The ideal stool sample for parasitic examination is one that is freshly collected and submitted to the laboratory at:

A. Refrigerator temperature (2° C)
B. Incubation temperature (37° C)
C. A temperature of -70° C
D. Room temperature (approximately 22° C)

D

10. What is the optimal specimen type to diagnose a Naegleria fowleri infection?

A. Whole blood sample
B. Water sample
C. Stool sample
D. Cerebrospinal fluid(CSF) sample

D

11. Which parasite can be recovered from the eye?

A. Entamoeba histolytica
B. Paragonimus spp.
C. Trichinella spp.
D. Toxoplasma gondii

D

12. A stool specimen has been left at room temperature overnight. The next day, many motile larvae with a short buccal cavity are seen upon microscopic exam, but there are no ova observed. What is the most likely identification and life stage of this parasite?

A. Necator americanus - rhabditiform larvae
B. Strongyloides stercoralis - adult
C. Ancylostoma duodenale - filariform larvae
D. Strongyloides stercoralis - rhabditiform larvae

D

13. Whipworm infection may be diagnosed in stool specimens by microscopic observation of adult worms or barrel-shaped eggs with polar plugs. Which species is known as the whipworm?

A. Trichuris trichiura
B. Ascaris lumbricoides
C. Necator americanus
D. Enterobius vermicularis

A

14. How long after hospitalization would stool samples be rejected for testing for parasitic infections?

A. No set time
B. Greater than 24 hours
C. Greater than 48 hours
D. Greater than 72 hours

D

15. Which of the following is the rigid, nonmotile diagnostic stage of the amebae which is generally found in the formed stool?

A. Oocyst
B. Cyst
C. Trophozoite
D. Sporozoite

B

16. Which of the following substances, when present in a sample, may mask parasites?

A. Barium
B. Saline
C. Phosphasoda
D. Antimicrobials

A

17. Parasites which can be found in urinary sediment include all of the following EXCEPT:

A. Enterobius vermicularis
B. Trichomonas vaginalis
C. Plasmodium malariae
D. Schistosoma haematobium

C

18. Upon reviewing a fecal preparation for Ova and Parasites, a technologist thought they had just identified the egg of Taenia saginata. After a quick look, the microbiology supervisor reminded the technologist that T. saginata eggs are indistinguishable from which of the following?

A. Dipyllidium caninum
B. Echinococcus granulosus
C. Hymenolepis diminuta
D. Taenia solium

D

19. Methods of detecting and identifying intestinal parasites include all of the following except:

A. Molecular methods
B. Wet mounts
C. Permanent stained smears
D. Thin and thin Giemsa smear

D

20. Which malaria pathogen is associated with massive hemolysis, blackwater fever, and blockage of capillaries?

A. Plasmodium vivax
B. Plasmodium falciparum
C. Plasmodium ovale
D. Plasmodium malariae

B

21. All of the following are primary routes of transmission for intestinal amoebae, EXCEPT?

A. The ingestion of cysts in contaminated food
B. The bite of an insect
C. The ingestion of cysts in contaminated drink
D. Hand-to-mouth contamination

B

22. The trophozoite is the only morphologic form in the life cycle of:

A. Trypanosoma cruzi
B. Pentatrichomonas hominis
C. Chilomastix mesnili
D. Retortamonas intestinalis

B

23. Which parasite is transmitted via a mosquito bite?

A. Wuchereria bancrofti
B. Leishmania braziliensis
C. Loa loa
D. Babesia spp.

A

24. Which one of the following parasites gives birth to live larvae known as microfilariae?

A. Strongyloides stercoralis
B. Necator americanus
C. Diphyllobothrium latum
D. Onchocerca volvulus

D

25. Trypanosoma cruzi is the etiologic agent of:

A. African sleeping sickness
B. Relapsing fever
C. Filariasis
D. Chagas' disease

D

26. The common name of which parasite is the sheep liver fluke?

A. Fasciolopsis buski
B. Fasciola hepatica
C. Clonorchis sinensis
D. Paragonimus westermani

B

27. Which organism is considered free-living amoebae?

A. Entamoeba coli
B. Trichomonas vaginalis
C. Naegleria fowleri
D. Endolimax nana

C

28. What is the recommended treatment if the patient is passing both cysts and trophozoites with an Entamoeba histolytica infection?

A. Either a luminal amebicide or a tissue amebicide
B. Tissue amebicide followed by a luminal amebicide
C. Luminal amebicide
D. Tissue amebicide

B

29. Which of the following is the common name for Hymenolepis diminuta?

A. Pork tapeworm
B. Rat tapeworm
C. Dog tapeworm
D. Hydatid tapeworm

B

30. Each parasite listed below is correctly matched with its respective vector, EXCEPT:

A. Iodamoeba butschlii - pig
B. Trypanosoma cruzi - reduviid bug
C. Plasmodium vivax - mosquito
D. Loa loa - fly

A

31. All of the following parasites typically survive human stomach juices except:

A. Entamoeba gingivalis trophozoite
B. Endolimax nana cyst
C. Balantidium coli cyst
D. Entamoeba histolytica cyst

A

32. The episodes of fever and chills experienced by patients suffering from malaria are known as:

A. Parasitemias
B. Inflammations
C. Paroxysms
D. Relapses

C

33. The body of a cestode is known as its:

A. Proglottid
B. Scolex
C. Strobila
D. Rostellum

C

34. What term is defined as the presence of arthropods in or upon a human host:

A. Infection
B. Disease
C. Symbiosis
D. Infestation

D

35. Which of the following organisms is considered to be pathogenic?

A. Entamoeba histolytica
B. Entamoeba coli
C. Chilomastix mesnili
D. Trichomonas hominis

A

36. In the life cycle of the intestinal trematodes, Fasciolopsis/Fasciola and Heterophyes, which of the following is known to infect snails?

A. Coracidium
B. Onchosphere
C. Miracidium
D. Rhabditiform

C

37. Adult forms of the following worms are all hermaphroditic, EXCEPT:

A. Hymenolepis
B. Taenia
C. Schistosoma
D. Clonorchis

C

38. The class of protozoa with no apparent organelles for locomotion is known as:

A. Mastigophora
B. Sporozoa
C. Ciliata
D. Sarcodina

B

39. Which malarial parasite is most likely present in a patient with a stained blood smear that reveals giant platelets, many reticulocytes containing Schuffner's dots, large ring forms, and schizonts with 12-24 merozoites?

A. Plasmodium falciparum
B. Plasmodium malariae
C. Plasmodium ovale
D. Plasmodium vivax

D

40. Human infection of the Schistosomes occurs following penetration of what morphologic form into the skin?

A. Eggs
B. Miracidia
C. Rediae
D. Cercariae

D

41. Which of the following amoebae has a flagellate form as part of its life cycle?

A. Trichomonas tenax
B. Pneumocystis jirovecii
C. Acanthamoeba spp.
D. Naegleria fowleri

D

42. Which of these parasites are hermaphroditic in their adult phase?

A. Clonorchis sinensis
B. Schistosoma haematobium
C. Wuchereria bancrofti
D. Trichuris trichiura

A

43. Which organism is considered nonpathogenic?

A. Dientamoeba fragilis
B. Balantidium coli
C. Blastocystis hominis
D. Chilomastix mesnii

D

44. Which Plasmodium morphologic form is considered most immature?

A. Trophozoite
B. Schizont
C. Microgametocyte
D. Macrogametocyte

A

45. The Echinococcus granulosus life cycle requires both an intermediate host (sheep) and definitive host (dogs), as humans are an accidental intermediate. While the eggs are ingested by humans and sheep, what structures need to be ingested by the definitive host, dogs, in order to complete the life cycle of Echnicoccus?

A. Eggs
B. Cysts
C. Proglottids
D. Adult worms

B

46. Of the protozoa listed below, which of the following can be routinely cultured?

A. Acanthamoeba species
B. Toxoplasma gondii
C. Chilomastix mesnili
D. Entamoeba histolytica

A

47. Enterobius vermicularis infection is acquired by:

A. Skin penetration of larvae
B. Insect bite
C. Ingestion or inhalation of egg
D. Ingestion of infected fish

C

48. Which of the following parasites migrate either to or through the lungs in their corresponding life cycle?

A. Fasciola species
B. Taenia solium
C. Entamoeba histolytica
D. Paragonimus westermanni

D

49. Houseflies are a possible transport host for which of these categories of parasites?

A. Sporozoa and amebae
B. Amebae and hemoflagellates
C. Hemoflagellates and flagellates
D. Flagellates and amebae

D

50. A specimen suspected of containing which organism may be cultured by placing it on an agar plate with an overlay growth of Escherichia coli?

A. Entamoeba coli
B. Schistosoma japonicum
C. Acanthamoeba species
D. Taenia species

C

51. This organism is found endemically on the New England seacoast. When seen in peripheral blood smears, it resembles a parasite of the genus Plasmodium. When an organism resembling malarial parasites is found in the peripheral blood, it is most probably:

A. Leishmania donovani
B. Trypanosoma cruzi
C. Babesia
D. Loa loa

C

52. Which type of Plasmodium infection has a 72-hour cycle, tends to infect old cells, and will have normal sized red blood cells?

A. Plasmodium vivax
B. Plasmodium ovale
C. Plasmodium malariae
D. Plasmodium falciparum

C

53. Consider the following matches of parasites with their common names. Each is a correct match EXCEPT:

A. Blood fluke = Schistosoma japonicum
B. Pork tapeworm =Taenia saginata
C. Chinese liver fluke = Clonorchis (Opisthorchis) sinensis
D. New World Hookworm = Necator americanus

B

54. Coccidia parasites are often acquired by fecal-oral routes by ingesting contaminated food or water. All of the following are coccidia parasites EXCEPT?

A. Sarcocystis species
B. Cryptosporidium parvum
C. Trypanosoma cruzi
D. Isospora belli

C

55. Which microscopic, intestinal parasite is the only ciliate that is pathogenic for humans?

A. Giardia duodenalis
B. Balantidium coli
C. Blastocystis hominis
D. Cystoisosospora belli

B

56. Multiple ring forms in one red blood cell are most frequently seen in which Plasmodium species infections?

A. P. falciparum
B. P. vivax
C. P. malariae
D. P. ovale

A

57. The first intermediate host in all of the fluke life cycles are the:

A. Copepods
B. Snails
C. Fish
D. Water plants

B

58. What is the largest protozoan known to infect humans?

A. Entamoeba coli
B. Balantidium coli
C. Entamoeba histolytica
D. Naegleria fowleri

B

59. Which parasitic infection may result from human ingestion of contaminated fish?

A. Dipylidium caninum
B. Taenia saginata
C. Taenia solium
D. Diphyllobothrium latum

D

60. Adult Ascaris lumbricoides worms reside in the:

A. Lungs
B. Liver
C. Small intestines
D. Large intestines

C

61. Which of the following parasites has a life cycle that most closely resembles that of Plasmodium species?

A. Dracunculus medinensis
B. Blastocystis hominis
C. Babesia microti
D. Toxoplasma gondii

C

62. Trichomonas, Giardia, and Chilomastix belong to the following parasitic group based on the type of motility:

A. Amoebae
B. Flagellates
C. Ciliates
D. Microsporidia

B

63. All of the following life stages of schistosome worms are appropriately matched with the host they are found in, EXCEPT:

A. Cercaria - cow
B. Sporocysts - snail
C. Adult worm - human
D. Egg - human

A

64. As one of the morphological families of parasites, a feature that characterizes various Nematode species is:

A. Disease cannot be transmitted via a fecal to oral route.
B. Filariform larvae may serve as an infective form for humans.
C. They are hermaphroditic.
D. Addition of proglottids is the method by which they mature.

B

65. Not all strains of Entamoeba histolytica appear to be pathogenic, and recent molecular studies indicated that there was a non-pathogenic variant of Entamoeba histolytica. What is this non-pathogenic variant?

A. Entamoeba hartmanni
B. Entamoeba moshkovkii
C. Entamoeba dispar
D. Entamoeba coli

C

66. The infective stage for the majority of all intestinal amebae is the:

A. Trophozoite
B. Cyst
C. Larva
D. Egg

B

67. Which of the following parasites has the longest undulating membrane?

A. Trichomonas vaginalis
B. Trichomonas tenax
C. Trichomonas hominis
D. Dientamoeba fragilis

C

68. Dracunculus medinensis belongs to this category of parasites?

A. Cestode
B. Nematode
C. Filaria
D. Trematode

B

69. All of the following parasites are correctly matched with its respective primary symptom, EXCEPT:

A. Enterobius vermicularis - perianal itching
B. Plasmodium falciparum - fever and chills
C. Trichomonas vaginalis - diarrhea
D. Endolimax nana - usually no symptoms

C

70. Which of the following organisms is an obligate intracellular parasite?

A. Proteus
B. Escherichia
C. Klebsiella
D. Rickettsia

D

71. Which of the following is matched correctly?

A. Enterobius vermicularis ova - ovoid in shape with one side flattened. The embryo is separated from the shell by a clear space.
B. Trichomonas vaginalis - is considered an important factor in the etiology of carcinoma of the bladder. The ova are elongated and are 60 X 160 microns. They are a yellowish color, slightly transparent, and possess a delicate terminal spine.
C. Schistosoma haematobium ova - have a characteristic oval body with a long thin tail and are 50 microns in length.
D. Sperm - is highly motile, measuring 8 - 15 microns with a characteristic pear shape. It has multiple anterior flagella and the nucleus is often apparent.

A

72. Which of the following parasites resembles Entamoeba histolytica, but lacks ingested red blood cells in the trophozoite form?

A. Entamoeba hartmanni
B. Entamoeba coli
C. Entamoeba gingivalis
D. Endolimax nana

A

73. Trichuris trichiura belongs to which of the following helminth groups?

A. Filariae
B. Trematodes
C. Nematodes
D. Cestodes

C

74. In the hookworm life cycle, which of the following is considered the noninfective larval form?:

A. Rhabditiform
B. Filariform
C. Proglottids
D. Cercariae

A

75. Parasitized animals that may serve as a source of infection for humans are called:

A. Definitive hosts
B. Accidental hosts
C. Reservoir hosts
D. Intermediate hosts

C

76. Which of the following parasites is/are considered as atrial ameba(e)?

A. Naegleria fowleri
B. Trichomonas vaginalis
C. Chilomastix mesnili
D. Toxoplasma gondii

A

77. The term "hydatid sand" is used in reference to which of the following tapeworms?

A. Taenia saginata
B. Echinococcus species
C. Hymenolepis diminuta
D. Hymenolepis nana

B

78. Which of the following parasites causes both intestinal and extraintestinal amebiasis?

A. Entamoeba coli
B. Endolimax nana
C. Iodamoeba butschlii
D. Entamoeba histolytica

D

79. Consider the following characteristics of hookworm infection. Each is correct EXCEPT:

A. Filariform larvae penetrate human skin into the blood.
B. Larvae are carried in the blood to the bronchial tree where they mature in the lungs.
C. Larvae are swallowed and travel to the small intestine where they mature.
D. Gastrointestinal symptoms may include diarrhea, nausea and hemorrhage.

B

80. Which of the following helminths is a tissue nematode whose life cycle resides in a single host?

A. Trichinella spiralis
B. Taenia solium
C. Taenia saginata
D. Diphyllobothrium latum

A

81. Which of the following human parasite spreads its infection through ingestion of raw meat or from oocysts from cat feces?

A. Microsporidium
B. Toxoplasma gondii
C. Cryptosporidium spp.
D. Enterocytozoon bieneusi

B

82. Which of the following is considered the technique of choice for isolating the oocysts of Isospora belli and Cryptosporidium parvum?

A. Knott technique
B. Giemsa stain
C. Trichrome stain
D. Zinc sulfate flotation

D

83. Adult cestodes utilize which body part to attach to the human intestine?

A. Strobila
B. Tegument
C. Proglottids
D. Suckers

D

84. What is a human infection caused by flukes called?

A. Elephantiasis
B. Distomiasis
C. Zoonoses
D. Swimmer's itch

B

85. Which of the following organisms is considered a Helminth?

A. Trypanosoma brucei rhodesiense
B. Leishmania braziliensis
C. Entamoeba histolytica
D. Schistosoma mansoni

D

86. Although not always the most practical, animal inoculation may be used to identify all but which of the following conditions?

A. Malaria
B. Leishmaniasis
C. Toxoplasmosis
D. Trypanosomiasis

A

87. The diagnostic stage for helminths is:

A. Egg
B. Trophozoite
C. Oocyst
D. Microfilaria

A

88. A 32-year-old male was seen in the emergency room with gastrointestinal discomfort. Upon questioning the patient it was learned that he first began feeling ill after spending a day at the park where he swam and played volleyball barefooted. He first noticed a lesion on his foot. Later, he developed vague respiratory symptoms. Now his largest complaint is severe abdominal pain along with occasional vomiting. This patient is most likely suffering from a parasitic infection with:

A. Echinococcus granulosus
B. Necator americanus
C. Entamoeba histolytica
D. Trichuris trichuria

B

89. What is the anatomical feature of a tapeworm that possesses both male and female reproductive structures?

A. Brood capsule
B. Proglottid
C. Rostellum
D. Scolex

B

90. Which of the following groups correctly matches the parasite with its infective stage?

A. Entamoeba hartmanni : sporozoite
B. Plasmodium malariae : oocyst
C. Cryptosporidium species: cyst
D. Dientamoeba fragilis : trophozoite

D

91. Ingestion of viable larvae in improperly cooked pork could lead to human infestations with which organism?

A. Taenia saginata
B. Trichinella spiralis
C. Hymenolepis diminuta
D. Strongyloides stercoralis

B

92. The motile, feeding stage of the amoebas and flagellates is called:

A. Cysts
B. Trophozoites
C. Eggs
D. Larvae

B

93. Which of the following parasites has the egg as the infective stage of the parasite for humans?

A. Enterobius vermicularis
B. Taenia solium
C. Trypanosoma cruzi
D. Schistosoma mansoni

A

94. Which parasite corresponds with the sandfly as its insect vector?

A. Leishmania spp.
B. Plasmodium spp.
C. Loa loa
D. Trypanosoma cruzi

A

95. The stage of Ixodes tick most likely to transmit Lyme disease is:

A. Nymph
B. Larva
C. Adult
D. Egg

A

96. Which of the following parasites can cross the placenta and cause serious infection to the fetus?

A. Cryptosporidium parvum
B. Giardia lamblia
C. Toxoplasma gondii
D. Pneumocystis jiroveci (carinii)

C

97. Which of the following would be considered the definitive host of a parasite?

A. Humans
B. Insect vector
C. First host infected by the parasite
D. Host in which parasites reproduce sexually

D

98. Enterobius vermicularis infection is acquired by:

A. Skin penetration of larvae
B. Insect bite
C. Ingestion or inhalation of egg
D. Ingestion of infected fish

C

99. In which of the following categories does the helminth Ascaris lumbricoides belong?

A. Protozoan
B. Cestode
C. Trematode
D. Nematode

D

100. All of the following parasites typically survive human stomach juices except:

A. Entamoeba gingivalis trophozoite
B. Endolimax nana cyst
C. Balantidium coli cyst
D. Entamoeba histolytica cyst

A