medical microbiology test bank

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: A

Rationale: The correct answer is A: Neisseria meningitidis. This bacterium is a Gram-negative diplococcus commonly associated with meningitis. The patient's symptoms of fever, headache, and neck stiffness are classic signs of meningococcal meningitis. Neisseria meningitidis is known to cause outbreaks in crowded settings. Streptococcus pneumoniae (Choice B) is a common cause of bacterial meningitis but typically appears as Gram-positive cocci. Haemophilus influenzae (Choice C) can also cause meningitis but is more commonly seen in unvaccinated children. Klebsiella pneumoniae (Choice D) is a Gram-negative bacterium but is not a typical causative agent of meningitis.

Correct Answer: D

Rationale: The correct answer is D: tinea pedis. Athlete's foot is a fungal infection that affects the feet, specifically the skin between the toes and on the soles. "Tinea pedis" is the medical term for athlete's foot, with "tinea" meaning a fungal infection and "pedis" referring to the foot. A: tinea capitis refers to a fungal infection of the scalp, not the feet. B: tinea corporis refers to a fungal infection of the body, not specifically the feet. C: tinea versicolor refers to a fungal infection that causes discoloration of the skin, not typically on the feet. In summary, the other choices are incorrect because they refer to fungal infections affecting different parts of the body, whereas "tinea pedis" specifically refers to athlete's foot.

Correct Answer: D

Rationale: The correct answer is D: Chlamydia trachomatis. Lymphogranuloma venereum (LGV) is caused by Chlamydia trachomatis serovars L1, L2, and L3. These serovars infect the lymphatic system leading to swelling and inflammation. Choice A, Chlamydia pneumoniae, is associated with respiratory infections, not LGV. Choice B, Chlamydia psittaci, causes psittacosis in birds and humans. Choice C, Mycoplasma genitalium, is a separate STI but is not the causative agent for LGV. The key to the correct answer is understanding the specific pathogen responsible for LGV based on its clinical presentation and mode of transmission.

Correct Answer: B

Rationale: The correct answer is B: Sporadic disease. When an infection occurs in several persons without any epidemiological link, it is considered sporadic. This term is used to describe isolated cases that do not form a specific pattern or cluster. It indicates random occurrences and lack of connection between the affected individuals. A: Epidemic refers to a sudden increase in the number of cases of a disease within a specific population or region, usually linked by a common source or exposure. C: Endemic signifies the constant presence of a disease within a specific population or region, with cases occurring at a relatively stable rate. D: Pandemic indicates a global outbreak of a disease affecting a large number of people across multiple countries or continents.