foundations in microbiology test bank

Correct Answer: B

Rationale: The correct answer is B: All are correct. Candida albicans can cause skin infections such as candidiasis. Staphylococcus aureus and Streptococcus pyogenes are common bacteria that can also cause skin infections. Therefore, choice B is correct as all three microorganisms listed can cause skin infections. Choices A, C, and D are incorrect because individually, each of the microorganisms listed can cause skin infections.

Correct Answer: B

Rationale: The correct answer is B: Phenols. Phenols act on the cell surface by disrupting cell membranes and denaturing proteins, leading to cell death. Soaps (A) work by lifting dirt and microbes off surfaces, not directly acting on cell surfaces. Amines (C) are typically used as disinfectants targeting specific enzymes in microbes, not cell surfaces. Polymyxin (D) is an antibiotic that works by disrupting cell membranes internally, not on the cell surface.

Correct Answer: A

Rationale: The correct answer is A: Helicobacterial infection. This is the most probable leading mechanism of disease development in this case because the patient's symptoms, such as heartburn, epigastric pain, food intolerance, and presence of a duodenal ulcer with a positive urease test, are classic signs of Helicobacter pylori infection. This bacterium colonizes the stomach lining, leading to inflammation and ulcer formation. The exacerbations in spring and autumn could be due to seasonal variations in immune response. Choice B: Dietary allergy is incorrect because the symptoms and findings in the patient are more indicative of an infectious etiology rather than an allergic reaction to specific foods. Choice C: Autoantibody production is unlikely as there are no indications of an autoimmune process in this case. Choice D: Reduced prostaglandin synthesis is not the leading mechanism as the symptoms and findings are more consistent with an infectious cause rather than a deficiency in prostaglandin synthesis.

Correct Answer: B

Rationale: The correct answer is B: Jenner. Edward Jenner is credited with performing the first successful vaccination against smallpox in 1796. He used cowpox virus to inoculate individuals, leading to immunity against smallpox. Jenner's experiment laid the foundation for modern vaccination. Pasteur (A) is known for developing the germ theory of disease. Semmelweis (C) advocated for handwashing to prevent infections. Koch (D) identified the causative agents of several diseases but did not develop the smallpox vaccine.

Correct Answer: D

Rationale: The correct answer is D, "None of the above," because viruses like Parotitidis (mumps), Rubella, and Influenza A are not typically associated with reactivation under immunosuppressive therapy. Reactivation is more commonly seen in latent viruses like herpesviruses (e.g., herpes simplex, varicella-zoster), cytomegalovirus, and Epstein-Barr virus. These viruses can remain dormant in the body and reactivate when the immune system is compromised. Therefore, the correct answer is D, as the viruses mentioned in choices A, B, and C do not fit the criteria for reactivation under immunosuppressive therapy.