ATI RN
Microbiology Chapter 13 Test Bank Questions
Question 1 of 5
Examination of the duodenal contents revealed some pear-shaped protozoa with two nuclei and four pairs of flagella. The organisms had also two axostyles between the nuclei and a ventral adhesive disc. What protozoan representative was found in the patient?
Correct Answer: A
Rationale: Step 1: Pear-shaped protozoa with two nuclei, four pairs of flagella, two axostyles, and a ventral adhesive disc match the characteristics of Giardia lamblia. Step 2: Giardia lamblia is commonly found in the duodenum and causes giardiasis. Step 3: Lamblia is the correct answer as it specifically matches all the described characteristics. Summary: B, Toxoplasma, is incorrect as it does not match the described features. C, Leishmania, does not have the specific characteristics mentioned. D, Intestinal trichomonad, does not match the detailed descriptions given.
Question 2 of 5
A woman delivered a dead child with multiple developmental defects. What protozoan disease might have caused the intrauterine death?
Correct Answer: A
Rationale: The correct answer is A: Toxoplasmosis. Toxoplasmosis is a parasitic infection caused by Toxoplasma gondii, which can be transmitted from mother to fetus during pregnancy, leading to congenital toxoplasmosis. This infection can result in stillbirth, multiple developmental defects, and intrauterine death. Leishmaniasis (B), Malaria (C), and Amebiasis (D) are caused by different parasites and do not typically lead to intrauterine death or developmental defects in the fetus.
Question 3 of 5
From a medicinal herb a certain phytopathogenic microorganism was secured. In the nutrient medium it forms "fried egg"colonies. What is the most likely agent?
Correct Answer: C
Rationale: Step 1: "Fried egg" colonies typically refer to colonies with a raised center and flattened periphery, resembling the appearance of a fried egg. Step 2: Actinomycetes are filamentous bacteria known to form "fried egg" colonies in nutrient medium. Step 3: Actinomycetes are commonly found in soil and are known to be phytopathogenic microorganisms. Step 4: Actinomycetes produce secondary metabolites with medicinal properties, making them a likely agent from a medicinal herb. Overall, the correct answer is C (Actinomycetes) as they fit the description provided in the question and are commonly associated with the given scenario. The other choices are incorrect as they do not exhibit the specific characteristics mentioned in the question or are not typically associated with forming "fried egg" colonies in nutrient medium.
Question 4 of 5
A male patient has been diagnosed with gastric ulcer. Bacteriological examination of biopsy material from the affected part of stomach revealed small colonies of gram-negative, oxide reductase-positive flexibacteria that grew on the chocolate agar on the fifth day. Which of the following microorganisms is the most likely causative agent?
Correct Answer: A
Rationale: The correct answer is A: Helicobacter pylori. This bacterium is the most likely causative agent of gastric ulcers. Here's the rationale: 1. Helicobacter pylori is commonly associated with gastric ulcers. 2. It is a gram-negative bacterium that grows on chocolate agar and is oxide reductase-positive. 3. The slow growth on the fifth day is characteristic of H. pylori. 4. Campylobacter jejuni and Campylobacter fetus are not typically associated with gastric ulcers. 5. Mycoplasma hominis is a bacterium that lacks a cell wall and is not commonly found in gastric ulcers.
Question 5 of 5
A 9 y.o. child has been taking antibiotics on account of bronchopneumonia for a long time. There appeared pain and burning in the area of mucous membrane of his lips and tongue. Objectively: mucous membrane of lips and tongue has caseous and grey plaques that can be easily removed by a spatula leaving hyperemia foci on their spot. Microscopic examination of the plaques revealed mycelium. What is the most probable diagnosis?
Correct Answer: A
Rationale: The most probable diagnosis is A: Candidous cheilitis. Candidous cheilitis is a fungal infection caused by Candida species. In this case, the presence of mycelium on the plaques indicates a fungal infection. The symptoms of pain, burning, and grey plaques that can be easily removed leaving hyperemia are typical for Candidous cheilitis. Choice B (Exfoliative cheilitis) is characterized by scaling and peeling of the lips, not plaques with mycelium. Choice C (Leukoplakia) is a precancerous condition causing white plaques that cannot be easily removed. Choice D (Contactant allergic cheilitis) is an allergic reaction causing inflammation, not fungal plaques.