microbiology chapter 11 test bank

Correct Answer: D

Rationale: The correct answer is D: Cell cultures. Rotavirus diagnosis involves detecting viral antigens in stool samples using cell cultures. Cell cultures allow for the replication of the virus, facilitating its identification. A: Egg inoculation and B: Sensitive laboratory animals are not commonly used for Rotavirus diagnosis due to ethical concerns and practical limitations. C: Ascoli test is used for detecting specific proteins in serum, not for Rotavirus detection in stool samples. In summary, cell cultures are the most appropriate method for laboratory diagnosis of Rotavirus infection due to their ability to support viral replication and antigen detection.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Hospital-acquired infections can be caused by a variety of bacteria commonly found in healthcare settings. Staphylococcus aureus is a common cause of surgical site infections. Escherichia coli can cause urinary tract infections. Klebsiella pneumoniae is associated with pneumonia and bloodstream infections. Therefore, all three bacteria are frequently implicated in hospital-acquired infections due to their prevalence and ability to cause different types of infections in healthcare settings. Thus, the correct answer is D, as all of the listed bacteria are commonly associated with hospital-acquired infections.

Correct Answer: B

Rationale: Decontamination is the reduction or removal of unwanted chemical or biological agents to make an area safe. This includes cleaning, disinfecting, or sterilizing to eliminate harmful substances. Choice A is incorrect as decontamination doesn't necessarily involve killing all microorganisms. Choice C is incorrect as it focuses on stopping growth, not removing existing contaminants. Choice D is incorrect as it specifically mentions vegetative organisms, which may not cover all types of contaminants that need to be removed during decontamination. Thus, the correct answer is B as it accurately describes the process of decontamination.

Correct Answer: A

Rationale: Axial filaments, also known as endoflagella, are composed of proteins. These proteins form a helical structure that enables certain bacteria, such as spirochetes, to move in a corkscrew-like motion. Proteins are the main structural component of axial filaments due to their flexibility and ability to generate movement. Choice B, polyphosphates, are not typically associated with axial filaments, as they are more involved in energy storage and transfer. Choice C, volutin granules, are storage inclusions of inorganic polyphosphate and are not part of axial filaments. Choice D, carbohydrates, are not the primary component of axial filaments which are protein-based structures responsible for bacterial motility.

Correct Answer: C

Rationale: The correct answer is C, transplacental mechanism. Listeria monocytogenes can cross the placenta, infecting the fetus during pregnancy. This mechanism allows the bacteria to be transmitted from mother to baby in utero. Alimentary mechanism (A) involves ingestion of contaminated food, not direct transfer between individuals. Transmission (B) is a broad term that doesn't specify the specific route of Listeria transmission. Physical contact (D) is not a common mode of Listeria transmission compared to transplacental transmission in the case of maternal-fetal infection.