ATI RN
microbiology an evolving science test bank Questions
Question 1 of 5
A 40-year-old man developed skin redness and an swelling in the neck area, where eventually a small abscess appeared. The section the focus is dense and yellow-green colored. In the purulent masses there are white granules. Histologically there are fungal druses, plasma and xanthome cells, and macrophages detected. Specify the most correct etiological name of this pathological process?
Correct Answer: A
Rationale: The correct answer is A: Actinomycosis. This is a chronic bacterial infection caused by Actinomyces species. In this case, the description of dense yellow-green colored focus, white granules in purulent masses, and presence of fungal druses, plasma cells, xanthome cells, and macrophages all match the characteristics of actinomycosis. Actinomycosis typically presents with abscess formation containing sulfur granules, which are yellowish and granular. The other choices (B: Furuncle, C: Carbuncle, D: Syphilis) do not fit the clinical and histological features described in the question, making them incorrect options.
Question 2 of 5
Microscopic examination of a smear from a patient with gas gangrene revealed Gram-positive rods producing spores. What microorganism was identified?
Correct Answer: A
Rationale: The correct answer is A: Clostridium perfringens. Gas gangrene is caused by Clostridium perfringens, a Gram-positive rod bacterium that produces spores. This bacterium is anaerobic and commonly found in soil, where it forms spores that can survive harsh conditions. Clostridium tetani causes tetanus, not gas gangrene. Bacillus anthracis causes anthrax, not gas gangrene. Clostridium botulinum causes botulism, not gas gangrene.
Therefore, based on the characteristics of the microorganism described in the question, Clostridium perfringens is the correct identification.
Question 3 of 5
Botulism is a disease caused by the production of a potent neurotoxin by bacteria of the genus:
Correct Answer: D
Rationale: The correct answer is D: Clostridium. Clostridium bacteria produce the neurotoxin responsible for botulism. Clostridium botulinum is specifically known for causing this disease. Staphylococcus (
A), Klebsiella (
B), and Salmonella (
C) do not produce the neurotoxin associated with botulism. Staphylococcus typically causes skin infections, Klebsiella is often associated with pneumonia and urinary tract infections, and Salmonella is known for causing food poisoning.
Therefore, the correct answer is Clostridium due to its specific association with botulism.
Question 4 of 5
Which of the following drugs is not used to treat influenza
Correct Answer: A
Rationale: Acyclovir is an antiviral drug used to treat herpes infections, not influenza. Tamiflu, Amantadine, and Relenza are all antiviral drugs commonly used to treat influenza. Acyclovir works by inhibiting the replication of herpes viruses, so it is not effective against the influenza virus.
Therefore, the correct answer is A.
Question 5 of 5
Which bacteria are known to produce an endotoxin that can cause septic shock?
Correct Answer: D
Rationale: The correct answer is D because all three bacteria (Salmonella enterica, Escherichia coli, Pseudomonas aeruginosa) are known to produce endotoxins, specifically lipopolysaccharides in their cell walls. Endotoxins are released upon bacterial cell death and can trigger an immune response, leading to septic shock. Salmonella and E. coli are common causes of bacterial infections, while Pseudomonas is associated with nosocomial infections.
Therefore, all of the above choices are correct in terms of producing endotoxins that can cause septic shock.
Choices A, B, and C are incorrect individually because they do not encompass all the bacteria known to produce endotoxins that can lead to septic shock.