Clinical Parasitology Chapter 3 Ameobas

Transmission of I. bütschlii occurs when: (Objective 3-5A) A. The infective cysts are ingested in contaminated food or drink. B. The infective trophozoites are ingested in contaminated food or drink. C. Examining stool specimens from infected individuals D. An infected mosquito vector bites an unsuspecting human.

B

Which of the following is not true about E. coli? (Objectives 3-2, 3-5, and 3-7C) A. The parasite is found worldwide. B. It is considered to be a pathogen. C. The infection is transmitted through the ingestion of the infected cyst through contaminated food or drink. D. The infection can be prevented by adequate disposal of human feces and good personal hygiene practices.

B

Which of the following statements is not true about the cysts of E. polecki? (Objective 3-9A) A. Cysts vary in shape from spherical to oval. B. Cysts contain at least four nuclei. C. The typical cyst nucleus resembles that of E. histolytica. D. A diffuse glycogen mass may be present in the cytoplasm of cysts.

B

Which of the following statements is true regarding E. nana? (Objectives 3-2 and 3-7) A. E. nana is found primarily in cold regions of the world. B. E. nana is prevalent in areas in which poor hygiene and substandard sanitary conditions exist. C. E. nana is considered as a human pathogen, so treatment is mandatory. D. Humans can obtain protection from E. nana via vaccination.

B

A main difference between the trophozoites of E. hartmanni and E. histolytica is which of the following? (Objective 3-11A) A. Trophozoites of E. histolytica are smaller in size. B. Presence of pseudopods C. Trophozoites of E. hartmanni do not contain ingested red blood cells. D. Nuclear structure and peripheral chromatin

C

E. gingivalis: (Objectives 3-4, 3-5, and 3-7) A. Is an intestinal ameba B. Is a pathogen and must be treated with metronidazole C. Can be found in the mouth and in the genital tract D. Has a typical amebic life cycle (i.e., trophozoites and cysts)

C

Iodamoeba bütschlii cysts typically: (Objective 3-9A) A. Contain four nuclei B. Have a small karyosome in a central position C. Lack chromatoid bars D. Lack a glycogen mass

C

Practical measures for the control and prevention of N. fowleri include which of the following? (Objective 3-7C) A. Banning swimming at all times during the summer months B. Avoidance of chlorinating swimming pools and hot tubs C. Providing education and awareness in the medical community D. Avoidance of consuming contaminated food or water prior to swimming

C

The ameboid trophozoites of N. fowleri enter the human body through all of the following routes except: (Objective 3-5B) A. Entry through the nasal mucosa B. Inhalation of contaminated dust C. Sniffing contaminated water D. Ingesting contaminated food and drink

D

To prevent infection with Acanthamoeba species, contact lens wearers should avoid which of the following? (Objective 3-7C) A. Strenuous exercise B. Foods with high carbohydrate content C. Wearing clothing made of cotton D. Using homemade nonsterile saline solutions

D

Which of the following factors is not responsible for the asymptomatic carrier state of a patient infected with E. histolytica? (Objective 3-7A) A. Low virulence strain B. Low inoculation into host C. Intact patient's immune system D. Patient's blood type

D

Which of the following is a unique characteristic of E. gingivalis? (Objectives 3-5B, 3-9A, and 3-9C) A. The trophozoites exhibit active motility via their pseudopods. B. There is no known cyst form of this parasite. C. The trophozoite has a single nucleus with characteristics that resemble those of E. histolytica. D. E. gingivalis is the only ameba that may ingest white blood cells.

D

Infection with E. polecki is mainly transmitted to humans via which of the following? (Objective 3-5A) A. Ingestion of E. polecki trophozoite B. Ingestion of E. polecki cysts C. Humans do not get infected with E. polecki. D. Touching an injected pig or monkey

B

The appearance of an E. nana karyosome is usually which of the following? (Objective 3-9A) A. Granular B. Large and round C. Small and round D. Blotlike

B

The infective stage of E. histolytica is which of the following? (Objective 3-5) A. Trophozoite B. Cyst

B

Humans may acquire Acanthamoeba species by which of the following? (Objective 3-5B) A. Aspiration or nasal inhalation of the organisms B. Direct invasion of the parasites in the eye C. Swimming or bathing in contaminated water D. A or B

D

The trophozoites of E. coli: (Objective 3-9A) A. Have eight nuclei B. Have a typical nucleus consists of a large, often irregularly shaped karyosome that is eccentrically located C. Are characterized by a karyosome that is surrounded by evenly distributed peripheral chromatin D. Contain red blood cell inclusions

B

Column A Column B 1. Entamoeba histolytica ___ A. Stool 2. Entamoeba coli ___ B. Spinal fluid 3. Endolimax nana ___ C. Mouth scrapings 4. Entamoeba gingivalis ___ D. Corneal scrapings 5. Acanthamoeba spp. 6. Naegleria fowleri

123-a 4c 5bd 6b

Humans most often contract N. fowleri by which of the following? (Objective 3-5B) A. Swimming in contaminated water B. Kissing an infected person C. Practicing unprotected sex D. Ingestion of contaminated food

A

Infections with Acanthamoeba species are encountered in which of the following anatomical parts? (Objective 3-5) A. Eye B. Large intestines C. Lungs D. Liver

A

Infections with intestinal amebas are prevalent in which of the following? (Objective 3-2) A. Underdeveloped countries with poor sanitary conditions B. Beef consumers in the United States C. People traveling to Europe D. Japan, because of seafood diet

A

The known morphologic forms of Naegleria fowleri are: (Objective 3-5B) A. Ameboid trophozoites, flagellate forms, and cysts B. Ameboid trophozoites, immature cysts, and mature cysts C. Eggs, larvae, and adults D. Flagellate forms, cysts, and larvae

A

The term acanthopodia refers to: (Objective 1) A. Spinelike pseudopods B. Hairy projections C. Double-layer cell wall D. Large karyosome and no obvious peripheral chromatin

A

Which of the following is true regarding E. hartmanni? (Objectives 3-2, 3-4, 3-5, and 3-7) A. The organism is found worldwide. B. It is generally considered a pathogen and treatment is indicated. C. It is an extraintestinal ameba. D. The life cycle requires one morphologic form, the trophozoite.

A

Which of the following structures is (are) typical in trophozoites of E. histolytica? (Objective 3-9A) A. Single nucleus with a small karyosome B. Unevenly distributed peripheral chromatin C. Chromatoid bars D. Glycogen mass

A

Amebas transform from trophozoites to cysts on entry into an unsuspecting human. (Objective 3-5A) A. True B. False

B

E. histolytica infection is traditionally diagnosed by finding which of the following? (Objective 3-8) A. Adult and egg forms of the parasite in a suspected stool sample B. Trophozoites and/or cysts in a suspected stool sample C. Larvae in a suspected CSF sample D. Adult form of the parasite in suspected tissue samples

B

Formed stool specimens are more likely to contain which of the following? (Objective 3-8) A. Trophozoites B. Cysts

B

The specimen of choice for diagnosing Acanthamoeba species trophozoites and cysts is which of the following? (Objective 3-8) A. Urine B. Sputum C. Cerebrospinal fluid D. Stool

C

The specimen of choice for the recovery of N. fowleri is which of the following? (Objective 3-8) A. Sputum B. Stool C. Cerebrospinal fluid D. Urine

C

Which of the following prevention measures can control the spread of E. histolytica? (Objective 3-7C) A. Drinking tap water B. Using human feces as fertilizer C. Boiling water or treat with iodine crystals D. Practicing unsafe sex

C

Amebic dysentery is caused by: (Objective 3-6) A. Entamoeba histolytica B. Entamoeba coli C. Entamoeba gingivalis D. Endolimax nana

a

True/False. Treatment for patients with asymptomatic intestinal amebiasis is not recommended. (Objective 3-7) A. True B. False

a

Primary amebic meningoencephalitis is primarily caused by: (Objective 3-6) A. Entamoeba histolytica B. Naegleria fowleri C. Entamoeba gingivalis D. Acanthamoeba spp

b

Which of the following statements is not true about amebic trophozoites? (Objective 3-1) A. Trophozoites are delicate and motile. B. Trophozoites are easily destroyed by gastric juices. C. Trophozoites are resistant to the environment outside the host. D. Replication occurs in the trophozoite stage.

c