Parents with ill child came to the infectionist. They worked in one of the Asian countries for a long time. Child has eathy colored skin, loss of appetite, laxity, enlarged liver, spleen, peripheral glands. What protozoan illness can this child have?

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: A

Rationale: Step 1: Giardiasis is caused by Giardia intestinalis, which is a well-known protozoan parasite. Step 2: Protozoans are single-celled eukaryotic organisms commonly found in water sources. Step 3: Giardia intestinalis infects the intestine, causing symptoms like diarrhea and abdominal cramps. Step 4: Bacteria (Choice B) are prokaryotic organisms, different from protozoans. Step 5: Fungi (Choice C) are also eukaryotic but are not responsible for causing Giardiasis. Step 6: Viruses (Choice D) are not cellular and cannot independently cause Giardiasis. In summary, the correct answer is A (protozoan) because Giardia intestinalis is a protozoan parasite specifically known to cause Giardiasis, while the other choices (Bacterium, Fungus, Virus) do not match the characteristics of the

Correct Answer: B

Rationale: The correct answer is B: Vibrio cholerae. Cholera is caused by Vibrio cholerae, a gram-negative bacterium that produces a toxin leading to severe watery diarrhea. Shigella dysenteriae causes dysentery, not cholera. Salmonella enterica causes salmonellosis, not cholera. Clostridium perfringens is associated with food poisoning, not cholera. In summary, Vibrio cholerae is the correct answer because it is the specific bacterium known to cause cholera, while the other choices are associated with different diseases.

Correct Answer: A

Rationale: The correct answer is A: Bacterial DNA. PCR analysis detects specific DNA sequences, so a positive result for H. pylori indicates the presence of the bacterial DNA in the gastric biopsy specimen. This method identifies the genetic material of the bacterium, not the bacterium itself (choice C) or its toxins (choice B). Additionally, PCR does not directly detect bacterial enzymes (choice D) but rather focuses on genetic material for accurate identification. Therefore, in this case, the detection of H. pylori in the PCR analysis points to the presence of bacterial DNA, confirming the etiology of peptic ulcer disease.

Correct Answer: A

Rationale: The correct answer is A: Synthesize proteins. Bacterial ribosomes are responsible for translating mRNA into proteins through a process called translation. Ribosomes do not generate ATP (choice B), produce DNA (choice C), or synthesize lipids (choice D). These processes are carried out by other cellular components such as mitochondria for ATP production, DNA polymerase for DNA replication, and enzymes for lipid synthesis. The primary function of bacterial ribosomes is protein synthesis, making choice A the correct answer.

Correct Answer: B

Rationale: The correct answer is B: streptococci. This term refers to beadlike chains of cocci formed after cell division along a single axis. "Diplococci" (A) are pairs of cocci, "tetrads" (C) are groups of four cocci, and "sarcinae" (D) are cube-like groups of eight cocci. Streptococci is the most appropriate term for describing the specific arrangement mentioned in the question.

Correct Answer: A

Rationale: The presence of acid-fast bacilli stained red against a blue background indicates mycobacteria, specifically Mycobacterium tuberculosis in this case. Ziehl-Neelsen staining is commonly used to detect tuberculosis. Diphtheria is caused by Corynebacterium diphtheriae, which does not stain with Ziehl-Neelsen. Pneumonia is a general term for lung infections caused by various pathogens. Leprosy is caused by Mycobacterium leprae, which requires special staining methods different from Ziehl-Neelsen.

Correct Answer: B

Rationale: The correct answer is B: Gram negative coccobacillus. Bordetella pertussis, the causative agent of pertussis, is a gram-negative coccobacillus. This is because it is a small, rod-shaped bacterium that appears both as a bacillus (rod-shaped) and a coccus (spherical) shape. It does not retain the crystal violet stain in the Gram staining process, indicating its negative gram nature. Choice A is incorrect because pertussis is not a gram-positive bacillus. Choice C is incorrect because pertussis is not a long gram-negative rod-shaped bacterium. Choice D is incorrect as the other options do not accurately describe the morphology of Bordetella pertussis.

Correct Answer: A

Rationale: The correct answer is A: Lysozyme. Lysozyme is an enzyme that targets and breaks down the peptidoglycan in bacterial cell walls by cleaving the glycosidic bonds between the sugar components. This action weakens the cell wall, leading to bacterial cell lysis. Amylase (B) breaks down starch, not peptidoglycan. Protease (C) breaks down proteins, not peptidoglycan. Lipase (D) breaks down lipids, not peptidoglycan. Therefore, Lysozyme is the correct enzyme for breaking down peptidoglycan in bacterial cell walls.