ATI RN
medical microbiology test bank Questions
Question 1 of 5
An 18-year-old patient has developed candidiasis after the case of pneumonia treated with β- lactam antibiotic. What antimycotic agent should be prescribed?
Correct Answer: B
Rationale: The correct answer is B: Fluconazole.
Rationale:
1. Candidiasis is a fungal infection, so an antimycotic agent is needed.
2. β-lactam antibiotics like ampicillin can lead to fungal overgrowth, necessitating an antimycotic.
3. Fluconazole is an antifungal agent effective against Candida species.
4. Streptomycin is an antibiotic, not an antifungal.
5. Phthalylsulfathiazole is an antibacterial sulfonamide, not an antifungal.
6. Ampicillin is an antibiotic, not an antifungal.
Question 2 of 5
A patient consulted a dentist about limited (restricted) mouth opening (trismus). He has a history of a stab wound of the lower extremity. What infection may cause these symptoms?
Correct Answer: A
Rationale: The correct answer is A: Tetanus. Tetanus is caused by the bacterium Clostridium tetani, which produces a neurotoxin leading to muscle stiffness, including trismus (restricted mouth opening). The patient's history of a stab wound increases the likelihood of tetanus infection due to the spores entering the body through the wound.
Incorrect
Choices:
B: Brucellosis does not typically present with trismus and is more commonly associated with fever, joint pain, and fatigue.
C: Whooping cough presents with severe coughing fits but does not cause trismus.
D: Wound anaerobic infection may cause localized symptoms at the wound site but is less likely to cause trismus compared to tetanus.
Question 3 of 5
Sexually transmitted infection, Lymphogranuloma venerum, is caused by:
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.
Question 4 of 5
Which of the following is true regarding bacterial plasmids?
Correct Answer: B
Rationale:
Correct Answer: B - Plasmids are circular DNA molecules
Rationale:
1. Plasmids are extrachromosomal DNA molecules found in bacteria.
2. Plasmids are typically circular in structure, not linear.
3. Circular plasmids are easily replicated and transferred between bacteria.
4. Plasmids can carry genes for antibiotic resistance, making option C incorrect.
5. Not all bacteria have plasmids, making option D incorrect.
6. While plasmids can provide benefits, they are not essential for bacterial survival, making option A incorrect.
Question 5 of 5
Bacterial spores are resistant to harsh conditions due to:
Correct Answer: B
Rationale: The correct answer is B because the presence of calcium dipicolinate in bacterial spores helps protect their DNA from damage under harsh conditions. Calcium dipicolinate acts as a stabilizer, preserving the spore structure.
Choice A is incorrect as bacterial spores have a tough protein coat, not a lipid-rich membrane.
Choice C is incorrect as bacterial spores have very low metabolic activity.
Choice D is incorrect as bacterial spores have low water content to prevent damage during harsh conditions.