ATI RN
microbiology a systems approach test bank Questions
Question 1 of 5
The food preparation process in which not all microorganisms are killed, but the number of microbes capable of spoiling the food or causing disease is reduced, is called
Correct Answer: B
Rationale: The correct answer is B: pasteurization. This process involves heating food to a specific temperature to kill harmful bacteria while preserving the flavor and quality of the food. Sanitation (A) refers to maintaining cleanliness to prevent contamination. Disinfection (C) involves killing most, but not all, microbes on surfaces. Purification (D) typically refers to the process of removing impurities, not specifically targeting microbes. In this case, pasteurization best describes the process of reducing harmful microbes in food without completely eliminating all microorganisms.
Question 2 of 5
After starting treatment for pulmonary tuberculosis a patient complained about red tears and urine. What drug could cause such changes?
Correct Answer: A
Rationale: The correct answer is A: Rifampicin. Rifampicin is known to cause red discoloration of bodily fluids, including tears and urine, due to its side effect of harmless color changes. Benzylpenicillins (B and C) and Biseptol-480 do not typically cause such discoloration. Rifampicin's mechanism of action involves binding to bacterial RNA polymerase, leading to inhibition of RNA synthesis, which is unrelated to the mechanism of the other drugs. Thus, based on the unique side effect profile of Rifampicin and its mechanism of action, it is the most likely drug causing red tears and urine in this scenario.
Question 3 of 5
Microscopic analysis of tissue sampling from affected area of mucous membrane of oral cavity revealed bacillus in form of accumulations that looked like a pack of cigarettes. Ziehl-Neelsen staining gives them red colour. What kind of pathogenic organism was most likely revealed in tissue sampling?
Correct Answer: B
Rationale: The correct answer is B: M.tuberculosis. The description of bacillus in the form of accumulations resembling a pack of cigarettes and staining red with Ziehl-Neelsen staining is characteristic of Mycobacterium tuberculosis. M.leprae (Choice A) is associated with leprosy and does not typically appear as described. A.bovis (Choice C) is a type of Mycobacterium but is not typically found in the oral cavity. A.israilii (Choice D) is not associated with the characteristics mentioned in the question. Therefore, based on the specific characteristics described, M.tuberculosis is the most likely pathogenic organism revealed in the tissue sampling.
Question 4 of 5
A 49-year-old countryman got an itching papule on the dorsum of his right hand. In the centre there is a vesicle with serosanginous exudate. Within the next 2 days the patient developed a painless edema of hand and forearm. On the 4th day the temperature rose to 38,5oC, in the right axillary region a large painful lymph node was found. One daybefore the onset of the disease the patient had examined a dead calf. What is the most likely diagnosis?
Correct Answer: D
Rationale: The most likely diagnosis is D: Lymphocutaneous tularemia. The key clues include exposure to a dead animal, vesicle with serosanginous exudate, painless edema progressing to lymph node involvement, and fever. Tularemia is caused by Francisella tularensis, commonly acquired through contact with infected animals. The characteristic ulcer at the site of entry, lymphadenopathy, and systemic symptoms point towards tularemia. Cutaneous anthrax (A) presents with a painless ulcer and black eschar. Bubonic plague (B) typically presents with buboes (swollen lymph nodes) and fever. Carbuncle (C) is a deep skin infection typically caused by Staphylococcus aureus.
Question 5 of 5
A patient with convulsive contractions of facial muscles was admitted to the infectious disease ward. From a scratch on his lower right extremity analysts isolated bacteria with terminal endospores that gave them drumstick appearance. What bacteria are compliant with given description?
Correct Answer: A
Rationale: Step-by-step rationale for the correct answer (A - Clostridium tetani): 1. The patient has convulsive contractions of facial muscles, indicating tetanus. 2. Isolation of bacteria with terminal endospores that have a drumstick appearance is characteristic of Clostridium tetani. 3. Clostridium tetani produces tetanospasmin toxin causing muscle spasms. 4. Therefore, the correct answer is Clostridium tetani (A). Summary of why other choices are incorrect: B: Clostridium botulinum causes botulism, not tetanus. C: Clostridium perfringens causes gas gangrene, not tetanus. D: Bacillus anthracis causes anthrax, not tetanus.