ATI RN
microbiology chapter 14 test bank Questions
Question 1 of 5
In serologic reactions used in virology, a diagnostic antibody response should be taken into account if:
Correct Answer: D
Rationale: The correct answer is D because a fourfold increase in titer in the second serum sample indicates a significant rise in specific antibodies, which is crucial for diagnosing viral infections accurately. This increase is considered significant in serologic reactions as it shows a strong antibody response to the virus. A: A threshold increase may not be substantial enough to confirm a diagnostic antibody response. B: Dismissing the increase in titer would overlook important diagnostic information. C: A twofold increase may not be as indicative of a strong antibody response compared to a fourfold increase.
Question 2 of 5
Aflatoxins are produced by:
Correct Answer: D
Rationale: The correct answer is D: Genus Aspergillus. Aflatoxins are toxic compounds produced by certain species of fungi, particularly Aspergillus species. Aspergillus flavus and Aspergillus parasiticus are well-known producers of aflatoxins. These fungi can contaminate crops such as peanuts, corn, and tree nuts, leading to potential health risks. Cryptococcus (A), Actinomyces (B), and Streptococcus (C) are not known to produce aflatoxins. It is important to be aware of the sources and implications of aflatoxin contamination to ensure food safety and public health.
Question 3 of 5
All is true for bacterial spores EXCEPT:
Correct Answer: C
Rationale: The correct answer is C. Bacterial spores are NOT used for cell division. Bacterial spores are dormant, resistant forms of bacteria that are formed in response to harsh environmental conditions. They are not involved in cell division but rather serve as a survival mechanism for the bacteria. A: They can deform the cell or not - This is true. Bacterial spores can deform the cell or not depending on the conditions. B: They can be terminal, subterminal, and central - This is true. Bacterial spores can be located at different positions within the bacterial cell. D: They are formed for 6-8h - This is incorrect. The formation of bacterial spores can take variable time periods depending on the species and environmental conditions.
Question 4 of 5
A 23-year old medical student arrives in the student health clinic complaining of difficult in swallowing, sore throat, and chills. Upon examination, she is found to be running a fever and has white patches on her tonsils. A throat swab is positive for streptococcus pyogenes (group A). A diagnosis of acute pharyngitis is made. Her past medical history is unremarkable except an anaphylactic reaction to cefaclor two years ago. Which of the following would be a safe alternative for treating?
Correct Answer: D
Rationale: The correct answer is D: Clindamycin. Clindamycin is a lincosamide antibiotic that is safe to use in patients with a history of anaphylaxis to beta-lactam antibiotics like cefaclor. Clindamycin is effective against streptococcus pyogenes and is a suitable alternative in this case. Amoxicillin (choice A) is a beta-lactam antibiotic similar to cefaclor and may cause a cross-reactive allergic reaction. Meropenem (choice B) is a carbapenem antibiotic and not typically used for acute pharyngitis. Cephalexin (choice C) is a cephalosporin antibiotic and may also cause cross-reactivity in patients with a history of anaphylaxis to cefaclor.
Question 5 of 5
Which of these viruses is a laboratory product?
Correct Answer: C
Rationale: Rationale: 1. Vaccinia is a laboratory product used in smallpox vaccination. 2. Variola is the virus that causes smallpox, not a laboratory product. 3. Monkeypox is a naturally occurring virus, not a laboratory product. 4. Cowpox can be found in nature and is used in vaccine production, but it is not a laboratory product like Vaccinia.