microbiology a systems approach test bank

Correct Answer: A

Rationale: The correct answer is A: Break down antibiotics like penicillin. Beta-lactamase is an enzyme produced by bacteria to inactivate beta-lactam antibiotics like penicillin by breaking the beta-lactam ring. This mechanism helps bacteria resist the antibiotic's effects. The other choices are incorrect because beta-lactamase does not enhance protein synthesis, facilitate DNA replication, or transport nutrients. It specifically targets and deactivates beta-lactam antibiotics, making choice A the most appropriate answer.

Correct Answer: A

Rationale: The correct answer is A: Mycobacterium tuberculosis. 1. Bright-red acid-resistant bacilli indicate the presence of mycolic acids in the cell wall, characteristic of Mycobacterium species. 2. Found in groups or singularly suggests the clumping nature of acid-fast bacilli. 3. Growth appearing after 10-15 days on nutrient media is consistent with the slow growth rate of Mycobacterium tuberculosis. 4. Yersinia pseudotuberculosis (B) and Klebsiella rhinoscleromatis (D) are not acid-fast bacilli and do not match the growth characteristics described. 5. Histoplasma dubrosii (C) is a fungus, not a bacterium, and does not exhibit acid-fast staining or the described growth pattern.

Correct Answer: A

Rationale: The correct answer is A: Borrelia burgdorferi. This bacterium is associated with Lyme disease, a tick-borne illness. Borrelia burgdorferi is transmitted to humans through the bite of infected black-legged ticks. It causes a range of symptoms, including fever, rash, joint pain, and neurological problems. Summary: B: Clostridium botulinum is associated with botulism, a serious illness caused by a toxin produced by this bacterium. C: Escherichia coli is a common bacterium found in the intestines of humans and animals, some strains can cause food poisoning. D: Streptococcus pneumoniae is a bacterium that can cause pneumonia and other respiratory infections, but not Lyme disease.

Correct Answer: A

Rationale: Rationale: 1. Vaginitis is a common bacterial infection in the female reproductive system. 2. Toxic shock syndrome can be caused by certain bacterial infections. 3. Endometritis is inflammation of the endometrium often due to bacterial infections. 4. Salpingitis is inflammation of the fallopian tubes, commonly caused by bacteria. Summary: - Choice B: Nephritis is a kidney infection, not related to female reproductive system infections. - Choice C: Nephritis and cystitis are not specific to the female reproductive system. - Choice D: Cystitis is a bladder infection, not typically considered part of female reproductive system infections.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae are all bacteria associated with causing bacterial meningitis. Neisseria meningitidis commonly causes meningococcal meningitis, Haemophilus influenzae can cause H. influenzae type b meningitis, and Streptococcus pneumoniae is a common cause of pneumococcal meningitis. Therefore, all three bacteria are known to be causative agents of bacterial meningitis. The other choices are incorrect as they do not encompass all the bacteria associated with causing bacterial meningitis.