microbiology a systems approach test bank -Nurselytic

Correct Answer: C

Rationale: The correct answer is C: Thick peptidoglycan layer. Gram-positive bacteria have a thick peptidoglycan layer in their cell wall, which retains the crystal violet stain during Gram staining. This thick layer is a key characteristic feature that helps differentiate Gram-positive bacteria from Gram-negative bacteria.


Rationale:
1. Gram-positive bacteria retain the crystal violet stain due to their thick peptidoglycan layer.
2. This thick layer provides structural support and protection to the cell.
3. Gram-positive bacteria lack an outer membrane, which is a feature of Gram-negative bacteria (
Choice
A).
4. Thin peptidoglycan layer is a characteristic of Gram-negative bacteria, not Gram-positive (
Choice
B).
5. Presence of LPS (lipopolysaccharide) is a feature of Gram-negative bacteria, not Gram-positive (
Choice
D).

In summary, the presence of a thick peptidoglycan layer is a characteristic feature of Gram-positive

Correct Answer: D

Rationale: The correct answer is D: Sporotrichosis. Sporotrichosis is caused by the fungus Sporothrix schenckii, which commonly presents as a subcutaneous infection. In the given case, the presence of a small abscess with yellowish-green pus containing white granules is indicative of sporotrichosis. The histological examination showing drusen of a fungus, plasmatic and xanthome cells, and macrophages further supports the diagnosis of sporotrichosis.


Choice A: Actinomycosis is a bacterial infection caused by Actinomyces species, not a fungal infection.

Choice B: Aspergillosis is caused by Aspergillus species and typically presents as a pulmonary infection, not a subcutaneous abscess as described in the case.

Choice C: Candidosis is caused by Candida species and usually presents as mucocutaneous infections, not a subcutaneous abscess with the

Correct Answer: A

Rationale: The correct answer is A: Spores. In the Ozheshko staining method, spores appear blue with red terminal components. Spores are reproductive structures produced by some bacteria, fungi, and protozoa. Cilia are short, hair-like structures used for movement. Flagella are long, whip-like structures also used for movement. Capsules are outer protective layers surrounding some bacteria. In this case, the description of rod-like microorganisms with blue staining and red terminal components aligns with the characteristics of spores, making it the correct answer.

Correct Answer: C

Rationale: The correct answer is C: 10% of the infected men have no symptoms. This is true because gonorrhea can be asymptomatic in some individuals, leading to undiagnosed cases. Testicular pain and epididymal tenderness (choice
A) are not typical symptoms of gonorrhea in men. Painful urination (choice
B) may or may not be present. Purulent discharge (choice
D) is a common symptom but not always present.
Therefore, choice C is the most accurate statement regarding gonorrhea symptoms in men.

Correct Answer: A

Rationale: The correct answer is A: Reinfection. This is because the patient fully recovered from the initial syphilis infection after antibiotic therapy, indicating the elimination of the pathogen. Subsequently getting infected again with Treponema pallidum suggests a new exposure to the same pathogen, resulting in a new infection. Recurrence (
B) would imply the reactivation of the same infection, which is not the case here. Superinfection (
C) refers to a new infection that occurs on top of an existing infection, which is not the scenario described. Secondary infection (
D) typically refers to an infection that occurs after an initial infection weakens the immune system, which is not the case in this scenario.