ATI RN
medical microbiology test bank Questions
Question 1 of 5
The laboratory for especially dangerous infections conducts microscopic examination of pathological material from a patient with suspected plague. The sample was stained by Burri-Gins technique. What property of the causative agent can be identified by this technique?
Correct Answer: A
Rationale: The Burri-Gins staining technique is used to identify the presence of capsules around bacteria. Capsules are protective structures that some bacteria produce to evade the immune system. This technique stains the capsule, making it visible under a microscope.
Therefore, the correct answer is A: Capsule formation.
Incorrect:
B: Spore formation - Spores are not typically identified using the Burri-Gins staining technique.
C: Acid resistance - This property is not specifically identified by Burri-Gins staining.
D: Alkali resistance - This property is not specifically identified by Burri-Gins staining.
Question 2 of 5
Which IS NOT true about sexually transmitted infections?
Correct Answer: C
Rationale:
Step 1: Define sexually transmitted infections (STIs) as infections primarily spread through sexual contact.
Step 2: Understand that STIs can also be transmitted through non-sexual means like blood transfusions.
Step 3: Recognize that choice C is incorrect as it limits STIs to only sexually transmitted infections.
Step 4:
Therefore, the correct answer is C as it does not encompass all possible modes of transmission for STIs.
Summary:
Choices A, B, and D are incorrect as they all accurately describe the characteristics of sexually transmitted infections, while choice C is incorrect as it excludes other potential modes of transmission for STIs.
Question 3 of 5
Which ones of the following symptoms are not typical of botulism:
Correct Answer: D
Rationale: The correct answer is D. Botulism typically presents with symptoms such as dry mouth, difficulty swallowing, blurred vision, diplopia, and descending flaccid paralysis. Chills, fever, and loss of consciousness are not typical of botulism. Botulism is caused by a neurotoxin produced by Clostridium botulinum bacteria, which affects the nervous system leading to muscle weakness and paralysis, not fever or altered consciousness.
Therefore, choice D is the correct answer.
Question 4 of 5
A patient with pneumonia had sputum stained by the Gram method. The smear revealed Gram-positive cocci in pairs with a capsule. What is the most likely causative agent?
Correct Answer: A
Rationale: The correct answer is A: Streptococcus pneumoniae. This bacterium is a common cause of pneumonia and is known to appear as Gram-positive cocci in pairs with a capsule. The presence of a capsule is a key characteristic of S. pneumoniae. Staphylococcus aureus (
B) is a Gram-positive cocci but typically does not have a capsule. Neisseria meningitidis (
C) is a Gram-negative diplococcus, not a Gram-positive cocci. Klebsiella pneumoniae (
D) is a Gram-negative rod, not a Gram-positive cocci.
Therefore, based on the staining pattern and the presence of a capsule, Streptococcus pneumoniae is the most likely causative agent in this case.
Question 5 of 5
A 32 y.o. man is divorced, has an irregular sexual life. He complains of falling out of hair in the region of eyelashes, eyebrows, scalp. Objectively: diffuse alopecia is observed, eyebrow margin is absent, eyelashes are stair-like (Pinkus' sign). What examination should be carried out first of all?
Correct Answer: A
Rationale: The correct answer is A: Wasserman test, IFT. The patient's symptoms of diffuse alopecia and Pinkus' sign are suggestive of secondary syphilis. The Wasserman test and Immunofluorescence Test (IFT) are used to detect antibodies against Treponema pallidum, the bacterium causing syphilis. This would confirm or rule out syphilis as the underlying cause of the patient's symptoms.
Choice B (T.pallidum Immobilization Test) is similar to the Wasserman test but less commonly used.
Choice C (Detection of the nasal mucous membrane for M.leprae) is irrelevant as leprosy does not present with the described symptoms.
Choice D (Consultation of neuropathist) is premature without ruling out syphilis first. Thus, the Wasserman test, IFT should be the initial examination to investigate the likely cause of the patient's symptoms.