ATI RN
microbiology chapter 13 test bank Questions
Question 1 of 9
A patient with a deep tissue infection had Gram-negative rods isolated from the wound culture. The bacteria were oxidase-positive and non-lactose fermenters. What is the most likely causative agent?
Correct Answer: A
Rationale: The correct answer is A: Pseudomonas aeruginosa. This is because Pseudomonas is a Gram-negative rod, oxidase-positive, and non-lactose fermenter. These characteristics are typical of Pseudomonas species. B: Escherichia coli is a Gram-negative rod but is lactose fermenter and usually oxidase-negative. C: Klebsiella pneumoniae is a Gram-negative rod, non-lactose fermenter, but is usually oxidase-negative. D: Shigella dysenteriae is a Gram-negative rod, non-lactose fermenter, but is usually oxidase-negative and is more associated with causing shigellosis rather than deep tissue infections.
Question 2 of 9
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 9
Which of the statements is false:
Correct Answer: A
Rationale: The correct answer is A because spirochaetes are not bacilli; they are spiral-shaped bacteria. Bacilli are rod-shaped bacteria, making statement A false. Statement B is true as diplococci are spherical bacteria occurring in pairs. Statement C is true as rod-shaped bacteria have one diameter longer than the other. Statement D is true as coccobacilli are short, oval-shaped bacteria resembling cocci and rods. In summary, spirochaetes are spiral-shaped, not bacilli, making statement A false.
Question 4 of 9
N. Meningitidis grows on
Correct Answer: D
Rationale: The correct answer is D: Chocolate agar. Neisseria meningitidis is a fastidious organism that requires enriched media for growth. Chocolate agar contains heat-treated blood that provides essential nutrients for the growth of N. meningitidis. The other choices, A: Levine agar, B: Lowenstein-Jensen agar, and C: TCBS agar, do not provide the specific nutrients required for the growth of N. meningitidis. Therefore, only choice D, Chocolate agar, supports the growth of N. meningitidis due to its enriched composition.
Question 5 of 9
For the structure of rubella virus, it is true that
Correct Answer: A
Rationale: Step 1: Rubella virus belongs to the Togaviridae family, which typically exhibits icosahedral symmetry. Step 2: Icosahedral symmetry refers to a structure with 20 equilateral triangular faces, which is characteristic of many viruses, including rubella. Step 3: Therefore, choice A is correct as rubella virus indeed has icosahedral type of symmetry. Summary: - Choice B is incorrect as rubella virus is an ssRNA virus, not ssDNA. - Choice C is incorrect as rubella virus does have an envelope derived from the host cell membrane. - Choice D is incorrect as rubella virus does have glycoprotein spikes on its surface.
Question 6 of 9
Which of the following statements is NOT true about influenza viruses?
Correct Answer: D
Rationale: The correct answer is D because there is specific prophylaxis available for influenza, such as the flu vaccine. Choice A is incorrect as influenza viruses are not spherical, they are typically pleomorphic. Choice B is incorrect because hemagglutinin and neuraminidase are indeed antigenically variable, contributing to the need for annual flu vaccines. Choice C is incorrect as the susceptibility of the population to influenza viruses can vary depending on factors such as immunity and vaccination status.
Question 7 of 9
Langerhans cells, which play a role in defense against microbes, are located in the:
Correct Answer: A
Rationale: The correct answer is A: epidermis. Langerhans cells are a type of immune cell found in the epidermis, the outermost layer of the skin. They play a crucial role in the defense against microbes by capturing and presenting antigens to activate the immune system. The dermis (B), hypodermis (C), and subcutaneous layer (D) are located deeper in the skin and do not contain Langerhans cells. Therefore, the epidermis is the correct location for these immune cells to carry out their defensive functions.
Question 8 of 9
The flagellar antigen of the bacteria is known as:
Correct Answer: B
Rationale: The correct answer is B: H antigen. Flagellar antigen is typically referred to as the H antigen in bacteria. Flagella are the whip-like structures used for movement in bacteria, and the H antigen is specifically associated with the flagella. The other choices (A: D antigen, C: K antigen, D: F antigen) are not related to flagella in bacteria and are commonly associated with other types of antigens in bacterial classification.
Question 9 of 9
As an example of specific human parasites one can name Plasmodium falciparum, human pinworm and some others. The source of parasite invasion is always a human. Such specific human parasites cause the diseases that are called:
Correct Answer: A
Rationale: The correct answer is A: Anthroponoses. This term refers to diseases caused by specific human parasites that are transmitted directly from human to human. In this case, the source of parasite invasion is always a human host. This term specifically describes diseases caused by parasites that exclusively infect humans. Choice B: Zoonoses refers to diseases that can be transmitted from animals to humans. Choice C: Anthropozoonoses is a combination of zoonoses and anthroponoses, which is not applicable in this scenario. Choice D: Infections is a general term that does not specify the source or type of parasite causing the disease.