ATI RN
Foundations in Microbiology Test Bank Questions
Question 1 of 4
A patient who came to the doctor because of his infertility was administered to make tests for toxoplasmosis and chronic gonorrhoea. Which reaction should be performed to reveal latent toxoplasmosis and chronic gonorrhoea in this patient?
Correct Answer: C
Rationale: The correct answer is C: IFA - Immunofluorescence assay. Toxoplasmosis and chronic gonorrhea can be detected using serological tests like IFA. IFA detects specific antibodies in the patient's serum by using fluorescently labeled antibodies. This method is highly sensitive and specific for detecting both acute and latent infections. Explanation of Incorrect Choices: A: RIHA - Reverse indirect hemagglutination assay - This test is not commonly used for detecting toxoplasmosis or chronic gonorrhea. B: RDHA - Reverse direct hemagglutination assay - This test is not typically used for these specific infections. D: Immunoblot analysis - While Immunoblot analysis is a useful confirmatory test for certain infections, it is not the primary method for detecting toxoplasmosis or chronic gonorrhea.
Question 2 of 4
A 32 year old patient complains about heartburn and dull pain in the epigastrium that appear 2-3 hours after meal. Exacerbations happen in spring and in autumn. The patient has food intolerance of eggs and fish. Objectively: stomach palpation reveals painfulness in the gastroduodenal area. Electrophasoduodenoscopy revealed a 5 mm ulcer on the anterior wall of duodenum. Urease test is positive. What is the most probable leading mechanism of disease development?
Correct Answer: A
Rationale: The correct answer is A: Helicobacterial infection. This is the most probable leading mechanism of disease development in this case because the patient's symptoms, such as heartburn, epigastric pain, food intolerance, and presence of a duodenal ulcer with a positive urease test, are classic signs of Helicobacter pylori infection. This bacterium colonizes the stomach lining, leading to inflammation and ulcer formation. The exacerbations in spring and autumn could be due to seasonal variations in immune response. Choice B: Dietary allergy is incorrect because the symptoms and findings in the patient are more indicative of an infectious etiology rather than an allergic reaction to specific foods. Choice C: Autoantibody production is unlikely as there are no indications of an autoimmune process in this case. Choice D: Reduced prostaglandin synthesis is not the leading mechanism as the symptoms and findings are more consistent with an infectious cause rather than a deficiency in prostaglandin synthesis.
Question 3 of 4
An 18-year-old patient has developed candidiasis after the case of pneumonia treated with β-lactam antibiotic. What antimycotic agent should be prescribed?
Correct Answer: A
Rationale: The correct answer is A: Fluconazole. 1. Fluconazole is an antifungal agent effective against Candida species commonly causing candidiasis. 2. Streptomycin (B) is an antibiotic used for bacterial infections, not fungal. 3. Phthalylsulfathiazole (C) is an antibacterial agent, not antifungal. 4. Ampicillin (D) is a β-lactam antibiotic, which can actually contribute to fungal infections like candidiasis.
Question 4 of 4
During sanitary and bacteriological testing of water with the membrane filter technique there were revealed two red colonies on a membrane filter (Endo agar) through which 500 ml of water was filtred. Calculate the coli index and coli titer of the analyzed water:
Correct Answer: C
Rationale: The correct answer is C (coli index of 250 and coli titer of 4). The coli index is calculated by multiplying the number of colonies by the reciprocal of the volume filtered, which gives 2 colonies x (1/0.5 L) = 4. The coli titer is obtained by dividing the volume filtered by the number of colonies, which gives 0.5 L / 2 colonies = 0.25 L or 250 ml. This indicates the concentration of coliform bacteria in the water sample. Choice A (4 and 250) is incorrect because it has the correct coli index but the values are reversed for coli index and coli titer. Choice B (2 and 500) is incorrect as it provides the correct coli titer value but the values are reversed for coli index and coli titer. Choice D (500 and 2) is incorrect because it reverses the values for both coli index and coli titer.