Which of the following bacteria is a common cause of pneumonia?

Correct Answer: D

Rationale: The correct answer is D: All of the above. - Streptococcus pneumoniae is a common cause of community-acquired pneumonia. - Mycobacterium tuberculosis can cause pulmonary tuberculosis, which can present as pneumonia-like symptoms. - Pseudomonas aeruginosa is an opportunistic pathogen that can cause pneumonia in immunocompromised individuals. Therefore, all three bacteria can cause pneumonia, making option D the correct choice. Options A, B, and C are incorrect because they each represent a bacterium that can cause pneumonia, so only selecting one of them would not encompass all common causes of pneumonia.

Correct Answer: A

Rationale: Rationale for Correct Answer (A: Fluconazole): Fluconazole is an antifungal medication used to treat yeast infections caused by Candida albicans. It targets the fungal cell membrane, disrupting its structure and function. This makes it an effective treatment for oral thrush, which is caused by Candida overgrowth in the oral mucosa. The continuous use of antibiotics can disrupt the normal balance of microorganisms in the body, leading to fungal overgrowth. Fluconazole specifically targets the yeast fungi without affecting bacteria, making it the appropriate choice for this complication. Summary of Incorrect Choices: B: Biseptol - Biseptol is an antibiotic that targets bacteria, not fungi like Candida albicans. C: Tetracycline - Tetracycline is also an antibiotic that targets bacteria, not fungi. D: Furazolidone - Furazolidone is an antibiotic primarily used for treating bacterial infections, not fungal infections like oral thrush caused by Candida

Correct Answer: B

Rationale: The correct answer is B: rheumatic fever. Rheumatic fever is an inflammatory disease that can occur as a complication following a group A streptococcal infection. This is known as a post-streptococcal complication. It typically affects the heart, joints, skin, and brain. Endocarditis (choice A) is also a complication of streptococcal infections, but it is an infection of the heart valves, not an inflammatory disease like rheumatic fever. Nephritis (choice C) is inflammation of the kidneys and is not directly related to streptococcal infections. Cytomegalovirus (choice D) is a different viral infection and is not associated with streptococcal infections.

Correct Answer: A

Rationale: The correct answer is A: Chlamydia. Chlamydia lacks the essential enzymes for ATP synthesis and relies on host cell ATP. Enterococci, Rickettsia, and Staphylococci possess the necessary enzymes for ATP synthesis through cellular respiration. Chlamydia's inability to synthesize ATP makes it dependent on the host cell for energy production, distinguishing it from the other bacteria listed.

Correct Answer: A

Rationale: The correct answer is A: Isoniazid and rifampicin. These drugs are considered first-line treatment for tuberculosis due to their high efficacy and low toxicity. Isoniazid targets the cell wall of the tuberculosis bacteria, while rifampicin inhibits RNA synthesis. They are recommended by WHO as the first choice for treating tuberculosis. Choice B (Penicillin and erythromycin) is incorrect because these antibiotics are not effective against tuberculosis bacteria. Choice C (Trimethoprim and third generation cephalosporins) is incorrect because they are not considered first-line drugs for tuberculosis treatment. Choice D (All the listed above can be used depending on their resistance profile) is incorrect because only isoniazid and rifampicin are universally recognized as first-line drugs for tuberculosis regardless of resistance profile.