ATI RN
Microbiology An Introduction 13th Edition Test Bank Questions
Question 1 of 9
In order to establish the possible contamination of a medication with fungi, a nutrient medium was inoculated, which resulted in growth of large cream-like colonies. What nutrient medium was used in this case?
Correct Answer: A
Rationale: The correct answer is A: Sabouraud. Sabouraud agar is specifically designed to promote the growth of fungi due to its low pH and high glucose content. The cream-like colonies indicate fungal growth, as fungi often appear as fluffy or powdery colonies on Sabouraud agar. Lowenstein-Jensen is used for mycobacteria, Roux for diphtheria, and Loeffler for Corynebacterium diphtheriae. Therefore, Sabouraud is the most suitable medium for detecting fungal contamination based on the characteristics of the colonies formed.
Question 2 of 9
What is the role of bacterial plasmids?
Correct Answer: C
Rationale: The correct answer is C: Carry genes for antibiotic resistance. Bacterial plasmids are small, circular DNA molecules that can be transferred between bacteria, carrying genes such as antibiotic resistance. This allows bacteria to survive in the presence of antibiotics. Plasmids do not directly play a role in protein synthesis (choice A) or DNA replication (choice B). Plasmids are not responsible for motility (choice D) as that function is usually carried out by flagella or other cellular structures.
Question 3 of 9
All of the following are symptoms of endocarditis except:
Correct Answer: C
Rationale: The correct answer is C: leg swelling. Endocarditis is an infection of the inner lining of the heart chambers and valves. Symptoms typically include fever, chills, weight loss, and muscle aches due to the body's immune response to the infection. Leg swelling is not a common symptom of endocarditis. It may occur in conditions like heart failure but is not directly associated with endocarditis. Therefore, choice C is the correct answer. Choices A, B, and D are incorrect because fever and chills, weight loss, and muscle aches are commonly seen in endocarditis due to the systemic inflammatory response to the infection.
Question 4 of 9
Which group of drugs can be used to treat influenza?
Correct Answer: D
Rationale: The correct answer is D: Neuraminidase inhibitors. Neuraminidase is an enzyme crucial for the release of new viral particles from infected cells during influenza infection. By inhibiting neuraminidase, the spread of the virus is limited. Protease inhibitors (choice A) are used to treat HIV, not influenza. Beta-lactamase inhibitors (choice B) are used in combination with beta-lactam antibiotics to increase their effectiveness against bacteria, not viruses. Reverse transcriptase inhibitors (choice C) are used to treat HIV by blocking the enzyme responsible for replicating the virus's genetic material, but they are not effective against influenza.
Question 5 of 9
Microorganisms that show optimal growth in moderate temperatures (between 25° C and 40° C) are called:
Correct Answer: C
Rationale: The correct answer is C: mesophiles. Mesophiles are microorganisms that thrive in moderate temperatures, typically between 25°C and 40°C. This temperature range is ideal for their growth and reproduction. Thermophiles (A) prefer high temperatures, psychrophiles (B) thrive in cold temperatures, and psychrotrophs (D) can grow at refrigeration temperatures but have an optimal range above 20°C. Therefore, the mesophiles are the best fit for organisms that show optimal growth in moderate temperatures.
Question 6 of 9
Which bacteria are commonly associated with foodborne illnesses?
Correct Answer: D
Rationale: The correct answer is D because all three bacteria - Salmonella enterica, Clostridium botulinum, and Escherichia coli - are commonly associated with foodborne illnesses. Salmonella causes gastroenteritis, Clostridium botulinum causes botulism, and E. coli can lead to severe food poisoning. Each bacterium has different mechanisms of causing illness, but all can be transmitted through contaminated food. Choices A, B, and C alone are incorrect because they do not encompass the full spectrum of bacteria commonly linked to foodborne illnesses.
Question 7 of 9
Which bacteria is known for its ability to resist heat and radiation?
Correct Answer: B
Rationale: The correct answer is B: Bacillus subtilis. Bacillus subtilis is known for its ability to resist heat and radiation due to its formation of endospores, which are highly resistant structures that protect the bacterium from harsh environmental conditions. This resilience allows Bacillus subtilis to survive in extreme environments where other bacteria cannot. Explanation of other choices: A: Escherichia coli is not known for its exceptional resistance to heat and radiation. C: Pseudomonas aeruginosa is not particularly resistant to heat and radiation compared to Bacillus subtilis. D: Clostridium perfringens is not as well-known for its heat and radiation resistance as Bacillus subtilis.
Question 8 of 9
A Gram-negative, comma-shaped bacterium was isolated from a patient with cholera. What is the most likely microorganism?
Correct Answer: A
Rationale: The correct answer is A: Vibrio cholerae. 1. Vibrio cholerae is a Gram-negative, comma-shaped bacterium known to cause cholera. 2. Shigella dysenteriae causes dysentery, not cholera. 3. Salmonella typhi causes typhoid fever, not cholera. 4. Campylobacter jejuni causes gastroenteritis, not cholera. Therefore, based on the symptoms presented and the characteristics of the bacterium, Vibrio cholerae is the most likely microorganism.
Question 9 of 9
A patient with fever and chills had blood cultures revealing Gram-negative rods that were oxidase-positive and lactose non-fermenters. What is the most likely causative agent?
Correct Answer: A
Rationale: The correct answer is A: Pseudomonas aeruginosa. This is because Pseudomonas is a Gram-negative rod, oxidase-positive, and a lactose non-fermenter. The presence of fever and chills suggests a systemic infection, which is common with Pseudomonas. Salmonella typhi, Shigella dysenteriae, and Escherimalia coli are all Gram-negative rods but are typically lactose fermenters and do not match the characteristics described in the question.