ATI RN
microbiology an evolving science test bank Questions
Question 1 of 5
A patient consulted a stomatologist about purulent inflammation of his gums. What drug will be the most effective if it is suspected that a causative agent is an anaerobe?
Correct Answer: A
Rationale: The correct answer is A: Metronidazole. Anaerobic bacteria are sensitive to metronidazole due to its mechanism of action targeting their DNA. Metronidazole is often the drug of choice for treating infections caused by anaerobic bacteria. Gentamicin, Oxacillin, and Co-trimoxazole are not effective against anaerobes. Gentamicin is an aminoglycoside mostly used for aerobic bacteria, Oxacillin is a beta-lactam antibiotic effective against gram-positive bacteria, and Co-trimoxazole is a combination of sulfamethoxazole and trimethoprim mainly used for urinary tract infections and some respiratory infections.
Question 2 of 5
The relations between the macroorganism and the resident skin microflora are defined as:
Correct Answer: A
Rationale: The correct answer is A: Commensalism. In this relationship, the skin microflora benefits from the host without causing harm or benefitting it. This is evident in the mutualistic interaction where the microflora receive nutrients and a place to live, while the host remains unaffected.
Choice B, Infection, is incorrect because it implies harm to the host.
Choice C, Parasitism, is also incorrect as it involves one organism benefiting at the expense of the other.
Choice D, No correct answer, is not applicable here as Commensalism accurately describes the relationship between the macroorganism and skin microflora.
Question 3 of 5
Drug of first choice for the treatment of syphilis is:
Correct Answer: B
Rationale: The correct answer is B: Penicillin. Penicillin is the drug of first choice for treating syphilis due to its effectiveness in eradicating the bacterium Treponema pallidum, which causes syphilis. It is the most reliable treatment with well-established efficacy. Gentamicin (
A), ciprofloxacin (
C), and chloramphenicol (
D) are not recommended for treating syphilis as they are not effective against the specific bacteria causing the infection. Penicillin remains the gold standard for syphilis treatment.
Question 4 of 5
A toxic, odorless gas often used as a sterilizing agent in hospitals and dental officials is
Correct Answer: A
Rationale: The correct answer is A: ethylene oxide. Ethylene oxide is a toxic, odorless gas commonly used as a sterilizing agent in healthcare settings due to its ability to effectively kill bacteria, viruses, and fungi. It is a highly reactive compound that can penetrate porous materials, making it an ideal choice for sterilization purposes.
Incorrect choices:
B: Carbon dioxide is not used as a sterilizing agent and is not toxic.
C: Carbon monoxide is not commonly used for sterilization and has a distinct odor.
D: Propane is not used for sterilization in healthcare settings and is not odorless.
Question 5 of 5
Bacteria that have been identified as frequently responsible for nonsexually transmitted infections of the reproductive system include:
Correct Answer: A
Rationale: The correct answer is A (Escherichia coli, Gardnerella vaginalis, and Staphylococcus aureus) because they are known to commonly cause nonsexually transmitted infections of the reproductive system. Escherichia coli can cause urinary tract infections that can ascend to the reproductive system. Gardnerella vaginalis is associated with bacterial vaginosis, a common infection of the vagina. Staphylococcus aureus can cause infections in the reproductive system through various means.
Choices B, C, and D are incorrect:
B: Streptococcus faecalis, Klebsiella oxytoca, and Serratia marcescens are not commonly associated with reproductive system infections.
C: Clostridium tetani and Bacillus cereus are not typically involved in reproductive system infections.
D: Neisseria gonorrhoeae causes sexually transmitted infections, Helicobacter pylori causes gastrointestinal issues, and Pseudomonas aeruginosa is more