ATI RN
microbiology chapter 13 test bank Questions
Question 1 of 5
Which of the following best describes the function of bacterial capsules?
Correct Answer: B
Rationale: The correct answer is B: Enable bacterial adherence to surfaces. Bacterial capsules are a protective layer outside the cell wall that helps bacteria adhere to surfaces and evade host immune responses. This allows bacteria to colonize and infect host tissues. A: Enhancing bacterial motility is typically associated with flagella, not capsules. C: Bacterial DNA replication is not directly affected by capsules. D: Bacterial capsules do play a role in protecting bacteria from desiccation by providing a barrier against drying out. However, the primary function is enabling adherence to surfaces.
Question 2 of 5
A wound culture from a patient with an infected ulcer revealed Gram-positive rods with terminal spores. What is the most likely causative agent?
Correct Answer: A
Rationale: Step-by-step rationale: 1. Gram-positive rods with terminal spores suggest Clostridium genus. 2. Terminal spores are characteristic of Clostridium perfringens. 3. C. perfringens is known to cause wound infections. 4. Therefore, the most likely causative agent is Clostridium perfringens. Summary: A: Clostridium perfringens is correct due to its characteristic features and association with wound infections. B: Bacillus anthracis does not typically form terminal spores. C: Clostridium tetani causes tetanus, not wound infections. D: Bacillus cereus does not produce terminal spores like Clostridium perfringens.
Question 3 of 5
A patient with a deep tissue infection had Gram-negative rods isolated from the wound culture. The bacteria were oxidase-positive and non-lactose 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 non-lactose fermenter. These characteristics are typical of Pseudomonas species. B: Escherichia coli is a Gram-negative rod but is lactose fermenter and usually oxidase-negative. C: Klebsiella pneumoniae is a Gram-negative rod, non-lactose fermenter, but is usually oxidase-negative. D: Shigella dysenteriae is a Gram-negative rod, non-lactose fermenter, but is usually oxidase-negative and is more associated with causing shigellosis rather than deep tissue infections.
Question 4 of 5
Which bacteria is responsible for causing cholera?
Correct Answer: B
Rationale: The correct answer is B: Vibrio cholerae. Cholera is caused by this specific bacterium due to its production of cholera toxin, leading to severe watery diarrhea. Shigella dysenteriae causes dysentery, Salmonella enterica causes salmonellosis, and Clostridium perfringens causes food poisoning, none of which present with the characteristic symptoms of cholera.
Question 5 of 5
Which of the following is responsible for causing gonorrhea?
Correct Answer: A
Rationale: Neisseria gonorrhoeae is the correct answer because it is the specific bacterium responsible for causing gonorrhea. It is a sexually transmitted infection that primarily affects the genital tract. Neisseria gonorrhoeae is transmitted through sexual contact and can lead to symptoms such as painful urination, discharge, and pelvic pain. Chlamydia trachomatis (Choice B) is another sexually transmitted bacterium, but it causes chlamydia, not gonorrhea. Mycobacterium tuberculosis (Choice C) is responsible for tuberculosis, a different infectious disease that primarily affects the lungs. Treponema pallidum (Choice D) causes syphilis, another sexually transmitted infection that presents with distinct symptoms from gonorrhea. Therefore, Neisseria gonorrhoeae is the correct choice for causing gonorrhea due to its specific association with this particular infection.