Which of the following bacteria can cause urinary tract infections?

Correct Answer: D

Rationale: The correct answer is D, "All of the above." E. coli, P. aeruginosa, and S. aureus are all known to cause urinary tract infections. E. coli is the most common causative agent due to its presence in the gut. P. aeruginosa and S. aureus can also infect the urinary tract, although less frequently. Therefore, all three bacteria are potential pathogens for urinary tract infections.

Correct Answer: B

Rationale: The correct answer is B: psittacosis. Psittacosis is an infection caused by Chlamydia psittaci that primarily affects the lower respiratory tract, leading to pneumonia-like symptoms. Mycoplasma pneumoniae causes atypical pneumonia, not pharyngitis (Choice A). Chronic atrophic rhinitis (Choice C) and rhinoscleroma (Choice D) both affect the upper respiratory tract, not the lower respiratory tract. Psittacosis specifically targets the lower respiratory tract, making it the most appropriate answer.

Correct Answer: C

Rationale: Correct Answer: C - Immunological tolerance to the pathogen Rationale: 1. Immunological tolerance is when the immune system does not mount a response against specific antigens to prevent autoimmunity. 2. In the context of infection, tolerance to the pathogen means the immune system does not recognize the pathogen as a threat and does not initiate a protective response. 3. This lack of response leaves the host vulnerable to infection as there is no specific immune defense mechanism activated against the pathogen. Summary of incorrect choices: A: Opsonic action of antibody - enhances phagocytosis of pathogens B: Viral neutralization by specific antibody - prevents viral entry into host cells D: Neutralization of protein exotoxin - prevents the harmful effects of toxins produced by pathogens.

Correct Answer: B

Rationale: The correct answer is B because a supercapsid is a lipoprotein membrane that encloses the nucleocapsid, providing protection to the genetic material inside. This structure is distinct from the capsid which is the protein coat surrounding the nucleic acid. Choice A is incorrect as there is no shell located between the capsid and supercapsid. Choice C is incorrect as it describes the nucleocapsid itself, not the supercapsid. Choice D is incorrect as a protein envelope around the nucleic acid does not specifically refer to a supercapsid.

Correct Answer: D

Rationale: The correct answer is D: Neuraminidase inhibitors. Neuraminidase is an enzyme crucial for the release of new viral particles from infected cells during influenza infection. By inhibiting neuraminidase, the spread of the virus is limited. Protease inhibitors (choice A) are used to treat HIV, not influenza. Beta-lactamase inhibitors (choice B) are used in combination with beta-lactam antibiotics to increase their effectiveness against bacteria, not viruses. Reverse transcriptase inhibitors (choice C) are used to treat HIV by blocking the enzyme responsible for replicating the virus's genetic material, but they are not effective against influenza.