microbiology test bank

Correct Answer: A

Rationale: Step 1: Chlorhexidine belongs to the group of biguanides, making choice A accurate. Step 2: It is commonly used for disinfection of hands, skin, and mucous membranes. Step 3: It has a broad spectrum of antimicrobial activity, making it widely applicable. Summary: Choice B is incorrect as chlorhexidine is not classified as an alcohol. Choice C is incorrect as chlorhexidine has various applications. Choice D is incorrect as chlorhexidine is generally safe for use with low toxicity.

Correct Answer: D

Rationale: The correct answer is D: To determine the children that need to receive BCG vaccination. The Mantoux test is used to identify individuals who have been exposed to Tuberculosis (TB) and need BCG vaccination for protection. Parotitis (choice A) is a viral infection unrelated to TB. Allergization rate toward rickettsia (choice B) and immune stress toward diphtheria (choice C) are not related to the Mantoux test or BCG vaccination. Therefore, choice D is the correct answer as it aligns with the purpose of the Mantoux test.

Correct Answer: D

Rationale: The correct answer is D (15-Oct) because boiling items for at least 15 minutes is necessary to effectively kill most vegetative bacteria and viruses. This duration ensures that the water reaches a high enough temperature to destroy harmful microorganisms. Choices A, B, and C are incorrect because they do not provide a sufficient amount of time for the water to reach the necessary temperature to effectively kill bacteria and viruses. Shorter durations may not be effective in ensuring food safety.

Correct Answer: A

Rationale: The correct answer is A: TRUE. The structures and organs listed are indeed part of the immune system. The lymphatic system transports lymph, lymphoid tissue contains immune cells, lymph nodes filter lymph, thymus matures T-cells, and spleen filters blood and produces immune cells. This comprehensive network is crucial for defending the body against pathogens. Choice B is incorrect as all listed structures are components of the immune system. Choice C is also incorrect as the statement is universally true, not situational. Choice D is incorrect as the correct answer is A.

Correct Answer: A

Rationale: The correct answer is A: Streptococcus pneumoniae. The given characteristics match this bacterium: Gram-positive diplococci, catalase-negative, and alpha-hemolytic. S. pneumoniae is a common cause of community-acquired pneumonia. Other choices are incorrect because Staphylococcus aureus is catalase-positive, Enterococcus faecalis is not alpha-hemolytic, and Klebsiella pneumoniae is not Gram-positive diplococci.