medical microbiology test bank

Correct Answer: B

Rationale: The correct answer is B: Neisseria gonorrhoeae. This bacterium is known to cause gonorrhea, a sexually transmitted infection. Neisseria gonorrhoeae specifically infects the mucous membranes of the reproductive tract in both men and women. It is transmitted through sexual contact. Explanation of other choices: A: Chlamydia trachomatis is a bacterium that causes chlamydia, not gonorrhea. C: Mycoplasma genitalium is associated with non-gonococcal urethritis, not gonorrhea. D: Treponema pallidum is the bacterium that causes syphilis, not gonorrhea. Therefore, Neisseria gonorrhoeae is the correct answer based on its direct association with causing gonorrhea.

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.

Correct Answer: B

Rationale: The correct answer is B: Spirochete. Lyme disease is caused by the bacterium Borrelia burgdorferi, which is a spirochete. Spirochetes are spiral-shaped bacteria that move by rotating like a corkscrew, which is characteristic of Borrelia burgdorferi. A: Spirillum - Spirillum bacteria are helical-shaped but are not the causative agent for Lyme disease. C: Vibrio - Vibrio bacteria are curved or comma-shaped and are not associated with Lyme disease. D: Diplococcus - Diplococcus bacteria are spherical-shaped and typically occur in pairs, not the causative agent for Lyme disease. Therefore, the correct answer is B because Borrelia burgdorferi is a spirochete bacterium that causes Lyme disease.

Correct Answer: D

Rationale: The correct answer is D because all three choices, Clostridium botulinum, Morbillivirus morbillorum, and Clostridium tetani, can cause infections of the central nervous system (CNS). Clostridium botulinum can lead to botulism, which affects the nervous system. Morbillivirus morbillorum can cause measles, which can lead to viral encephalitis. Clostridium tetani can cause tetanus, which affects the CNS by producing neurotoxins. Therefore, all three choices are pathogens that can cause infections of the CNS.

Correct Answer: C

Rationale: The correct answer is C because both Mycobacterium bovis and Mycobacterium tuberculosis are bacteria that can cause tuberculosis in humans. Mycobacterium bovis primarily infects animals but can be transmitted to humans, while Mycobacterium tuberculosis is the main causative agent of tuberculosis in humans. Therefore, both choices A and B are correct. Choice D is incorrect because we know that Mycobacterium bovis and Mycobacterium tuberculosis are causative agents of tuberculosis in humans.