foundations in microbiology test bank

Correct Answer: C

Rationale: The correct answer is C: Survival. Bacterial spores are specialized structures that bacteria form to survive harsh conditions such as extreme temperatures or lack of nutrients. Spores are not used for protection against phagocytosis (A) as they are dormant structures and not actively involved in defense mechanisms. They are not for reproduction (B) as spores are a form of bacterial reproduction but not the primary purpose of spore formation. Spores do not serve as nutrient storage (D) as they are mainly used for survival during unfavorable conditions.

Correct Answer: A

Rationale: The correct answer is A: Staphylococcus aureus. Staphylococcus aureus is a Gram-positive cocci bacterium that forms clusters and commonly causes pneumonia with a productive cough and fever. It is frequently found in sputum smears in such cases. Streptococcus pneumoniae (B) is another common cause of pneumonia but typically appears in pairs or chains, not clusters. Neisseria meningitidis (C) is a Gram-negative diplococcus that causes meningitis, not pneumonia. Klebsiella pneumoniae (D) is a Gram-negative bacterium that can cause pneumonia but appears as Gram-negative rods, not Gram-positive cocci in clusters.

Correct Answer: B

Rationale: The correct answer is B: Yersinia pestis. Y. pestis is the causative agent of plague, a serious infectious disease transmitted through fleas. It causes bubonic, pneumonic, and septicemic plague. Bordetella pertussis causes whooping cough, Rickettsia prowazekii causes epidemic typhus, and Treponema pallidum causes syphilis. Y. pestis is the correct answer because it is specifically associated with plague, making the other options incorrect.

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.

Correct Answer: C

Rationale: The correct answer is C: enterotoxigenic E. Coli (ETEC). ETEC adheres to the intestine wall and produces toxins, leading to symptoms like diarrhea. Shigella spp. invade intestinal cells, Salmonella spp. cause inflammation, and Helicobacter pylori infects the stomach lining. This makes them incorrect choices for bacteria adhering to the intestine wall and producing toxins.