microbiology test bank

Correct Answer: A

Rationale: The correct answer is A: Nystatin. Nystatin is an antifungal medication, not an antibiotic used to treat bacterial infections like generalized meningococcal infection. Penicillin G, macrolides, and chloramphenicol are antibiotics commonly used to treat bacterial infections, including meningococcal infections. Penicillin G is the drug of choice for meningococcal infections, while macrolides and chloramphenicol are alternative options. Nystatin is not effective against bacteria, so it is not a suitable treatment for meningococcal infections.

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: C

Rationale: Rationale: 1. Both Clostridium botulinum and Bacillus anthracis are known to form spores. 2. Spore formation is a mechanism for survival in harsh conditions. 3. Both bacteria are capable of causing severe diseases in humans. Summary: - Choice A and B are incorrect because each bacteria listed is capable of spore formation. - Choice D is incorrect as both bacteria mentioned can form spores to survive extreme conditions.

Correct Answer: B

Rationale: Bacillus cereus is known to cause food poisoning due to the production of toxins in contaminated food. It is not the causative agent of anthrax or endocarditis. The correct answer is B because Bacillus cereus is commonly associated with foodborne illnesses, leading to symptoms such as nausea, vomiting, and diarrhea. It's essential to understand the specific characteristics and pathogenicity of Bacillus cereus to differentiate it from other bacterial infections.

Correct Answer: B

Rationale: The correct answer is B: Blood agar. Pneumococci are fastidious bacteria that require enriched media for cultivation. Blood agar provides essential nutrients and growth factors needed for the growth of pneumococci. It contains sheep blood, which provides hemin and NAD, supporting the growth of these bacteria. Kligler iron agar (A) is used for differentiating enteric bacteria based on glucose and lactose fermentation. Apocholate citrate agar (C) is used for the selective isolation of Escherichia coli. Peptone water (D) is a non-selective medium used for the initial cultivation of microorganisms.