During the skill-building session in microbiology the students need to stain the prepared and fixed sputum smears obtained from a tuberculosis patient. What staining technique should be used in this case?

Correct Answer: C

Rationale: The correct staining technique for sputum smears obtained from a tuberculosis patient is Ziehl-Neelsen staining. This technique uses carbol fuchsin dye to stain the acid-fast bacteria, such as Mycobacterium tuberculosis, red. Here's a step-by-step rationale: 1. Ziehl-Neelsen staining is specifically designed to detect acid-fast bacteria like Mycobacterium tuberculosis. 2. Carbol fuchsin dye is used to penetrate the mycolic acid layer in the cell wall of the bacteria, making them resistant to decolorization. 3. Acid-alcohol is used as a decolorizer to remove the stain from non-acid-fast bacteria. 4. Methylene blue is used as a counterstain to visualize non-acid-fast bacteria in blue. Therefore, Ziehl-Neelsen staining is the most appropriate technique for identifying Mycobacterium tuberculosis in sputum smears. Other choices like Gram, Giemsa, and

Correct Answer: A

Rationale: The correct answer is A because Fluconazole, Orungal, and Nizoral are antifungal medications commonly used for prevention of fungal infections. Fluconazole is a systemic antifungal agent, Orungal (Itraconazole) is used for various fungal infections, and Nizoral (Ketoconazole) is effective against a wide range of fungal infections. Choices B, C, and D do not contain antifungal medications and are unrelated to preventing fungal infections.

Correct Answer: B

Rationale: The correct answer is B because there is no effective killed vaccine that is protective against all capsular types of Haemophilus spp. The Haemophilus influenzae vaccine primarily targets specific capsular types, not all of them. Choice A is incorrect because non-encapsulated strains can indeed be isolated from healthy carriers. Choice C is incorrect as Haemophilus influenzae is primarily transmitted through respiratory droplets, not through the air. Choice D is not correct because Choice B is indeed incorrect, making it the right answer.

Correct Answer: D

Rationale: The correct answer is D because the flu vaccine primarily stimulates systemic immunity rather than local immunity. It is administered parenterally (C) as it is injected into the body. It is a subunit vaccine (B) as it contains only specific antigens of the virus. It is a recommended vaccine (A) due to its effectiveness in preventing influenza. In summary, D is the correct choice as the flu vaccine mainly targets systemic immunity, not local immunity, unlike the other characteristics listed.

Correct Answer: B

Rationale: The correct answer is B: adolescents. Infectious mononucleosis is commonly caused by the Epstein-Barr virus, which is transmitted through saliva. Adolescents are more likely to engage in activities like kissing and sharing drinks, increasing the chances of virus transmission. Infants have maternal antibodies for protection, young adults may have developed immunity, and the elderly have had more exposure to the virus and may have built immunity over time.

Correct Answer: A

Rationale: Step 1: The patient's symptoms align with tetanus infection, such as muscle spasms and fever. Step 2: Tetanus is caused by Clostridium tetani bacteria found in soil. Step 3: The wound from tilling soil provides an entry point for the bacteria. Step 4: Delayed seeking medical attention increases the risk of tetanus development. Step 5: Tetanus toxin affects the nervous system, leading to muscle stiffness and spasms. Summary: Choice A is correct due to symptom alignment, bacterial source, wound type, delayed treatment, and specific neurological effects. Choices B, C, and D lack these specific connections to the given scenario.

Correct Answer: C

Rationale: The correct answer is C: Helicobacter pylori. This bacterium is a well-known cause of peptic ulcers due to its ability to survive in the acidic environment of the stomach and produce enzymes that weaken the protective mucous layer of the stomach lining. Treponema pallidum (choice A) causes syphilis, Vibrio cholerae (choice B) causes cholera, and Escherichia coli (choice D) can cause various infections but is not a common cause of peptic ulcers. Therefore, Helicobacter pylori is the correct answer as it is specifically associated with peptic ulcer formation.

Correct Answer: A

Rationale: Rationale: 1. Metronidazole is known to inhibit aldehyde dehydrogenase, an enzyme involved in alcohol metabolism. 2. Inhibition of this enzyme leads to accumulation of acetaldehyde, causing unpleasant symptoms when alcohol is consumed. 3. This reaction is known as the disulfiram-like reaction. 4. Reserpine, Clonidine, and Diazepam do not have this specific mechanism of action. Summary: - Option A (Metronidazole) is correct due to its inhibition of alcohol metabolism. - Options B, C, and D are incorrect as they do not exhibit this interaction with alcohol metabolism.

Correct Answer: A

Rationale: The correct answer is A: BK virus. BK virus is a common cause of hemorrhagic cystitis, especially in immunocompromised individuals. It infects the urinary tract, leading to inflammation and bleeding in the bladder. Enteroviruses, Flaviviruses, and Coronaviruses do not typically cause hemorrhagic cystitis. Enteroviruses usually cause respiratory and gastrointestinal infections, Flaviviruses are commonly associated with diseases like dengue fever and Zika virus, and Coronaviruses are known for causing respiratory illnesses such as COVID-19. Hence, the correct answer is A as it is the only virus among the options known to cause hemorrhagic cystitis.