mcgraw hill microbiology test bank

Correct Answer: D

Rationale: The correct answer is D, "All of the above." Escherichia coli is the most common bacteria causing UTIs due to its ability to colonize the urinary tract. Salmonella enterica and Neisseria gonorrhoeae are not typically associated with UTIs. Therefore, by process of elimination, since A is correct, B and C are incorrect.

Correct Answer: A

Rationale: The correct answer is A: CMV (Cytomegalovirus). CMV is the most common congenital infection worldwide due to its high prevalence and ability to be transmitted from mother to fetus during pregnancy. It can lead to serious complications such as hearing loss, developmental delays, and vision problems in newborns. Listeria monocytogenes (B) is a foodborne pathogen, not typically associated with congenital infections. Rubella Virus (C) can cause congenital rubella syndrome but is less common globally compared to CMV. Syphilis (D) can also be transmitted from mother to fetus, but its prevalence and impact on congenital infections are lower compared to CMV.

Correct Answer: C

Rationale: The correct answer is C: High amount of mycolic acids. Mycobacteria are characterized by their unique cell wall composition, which includes a high amount of mycolic acids. Mycolic acids provide the bacteria with resistance to environmental stresses and are crucial for their pathogenicity. Polysaccharides (A) are not a prominent component of mycobacterial cell walls. While lipids (B) are present in mycobacterial cell walls, mycolic acids are the predominant lipid. Proteins (D) are also present but are not the defining feature of mycobacterial cell walls. Therefore, the correct answer is C due to the significant role mycolic acids play in the structure and function of mycobacterial cell walls.

Correct Answer: A

Rationale: The correct answer is A: cultivating on artificial media and biochemical identification. This method is appropriate for diagnosing listeriosis because it allows for the isolation and growth of Listeria species on selective media, followed by biochemical tests to confirm the identity. Serological diagnosis with ELISA (choice B) is not as specific for Listeria and may yield false positives. Choice C, serological diagnosis with agglutination hype Widal, is not typically used for listeriosis diagnosis. Cultivating in cell cultures (choice D) is not the primary method for diagnosing listeriosis as it is less specific compared to cultivating on artificial media and biochemical identification.

Correct Answer: A

Rationale: The correct answer is A: Volutin granules. Volutin granules are metachromatic granules that stain dark blue with methylene blue or Leishman stain. In diphtheria-causing bacteria, Corynebacterium diphtheriae, these granules are typically seen as yellow rods with dark blue thickenings on their ends when stained. Volutin granules are storage inclusions composed of polymetaphosphate that serve as an energy reserve for the bacteria. The presence of these granules in the detected microorganisms indicates the characteristic feature of Corynebacterium diphtheriae. Summary of other choices: B: Plasmids are extrachromosomal DNA molecules that are not typically visible on stained smears. C: Capsules are outer protective layers that are not visible on stained smears. D: Spores are reproductive structures formed by certain bacteria, not typically seen in Corynebacterium diphtheriae.