Correct Answer: C

Rationale: The correct answer is C: Visceral leishmaniasis. This disease is caused by the protozoan parasite Leishmania, which is transmitted by sandfly bites. The symptoms described in the question, such as enlarged liver and spleen, peripheral gland enlargement, and eathy colored skin, are characteristic of visceral leishmaniasis. Amebiasis (choice A) typically presents with gastrointestinal symptoms, Balantidiasis (choice B) is caused by a different parasite and presents with dysentery, and Lambliasis (choice D) is caused by Giardia lamblia and presents with diarrhea.

Correct Answer: B

Rationale: The correct answer is B: IgM. IgM antibodies are the first type of antibodies produced in response to an infection, indicating an active or recent infection. In the case of a rubella virus infection in a fetus, IgM antibodies can be detected in the umbilical cord blood, confirming the presence of the virus. IgA antibodies are mainly found in mucosal areas, IgG antibodies indicate past infection or immunity, and IgD antibodies play a role in B cell activation but are not typically detected in this context.

Correct Answer: A

Rationale: The correct answer is A: Clostridium tetani and Bacillus anthracis. Both bacteria produce exotoxins that damage host tissues. Clostridium tetani produces tetanospasmin, which causes muscle rigidity in tetanus. Bacillus anthracis produces anthrax toxins, leading to tissue damage and systemic effects. Explanation: - Choice B (Escherichia coli and Pseudomonas aeruginosa) primarily cause infections through other mechanisms and do not produce exotoxins that damage host tissues. - Choice C (Streptococcus pneumoniae and Listeria monocytogenes) are known for causing infections but not primarily through exotoxins that damage host tissues. - Choice D (Salmonella typhi and Mycobacterium tuberculosis) cause diseases through different mechanisms and do not produce exotoxins that directly damage host tissues.

Correct Answer: A

Rationale: The correct answer is A: Neisser staining. This method is specifically used to identify cytoplasmic inclusions by staining them with a specific dye that highlights these structures. Neisser staining is designed to selectively target and visualize cytoplasmic inclusions, making it the most appropriate choice for this purpose. Option B: Clett staining, Option C: Ziehl-Nielsen staining, and Option D: Gram staining are not typically used for identifying cytoplasmic inclusions. Clett staining is not a commonly known staining method for this purpose. Ziehl-Nielsen staining is primarily used to detect acid-fast bacteria like Mycobacterium tuberculosis. Gram staining is used to differentiate bacteria into Gram-positive and Gram-negative based on cell wall characteristics. Therefore, these options are not suitable for identifying cytoplasmic inclusions.

Correct Answer: B

Rationale: The correct answer is B: BKV. BK virus can cause hemorrhagic cystitis in immunocompromised patients by infecting the urinary tract. It primarily affects the renal tubular epithelial cells, leading to hemorrhagic cystitis. EBV (A) causes infectious mononucleosis, HSV1 (C) causes oral and genital herpes, and JCV (D) causes progressive multifocal leukoencephalopathy, none of which are associated with hemorrhagic cystitis.