Two weeks after hemotransfusion a patient developed fever. What protozoal disease can be suspected?

Correct Answer: A

Rationale: The correct answer is A: Malaria. Two weeks after hemotransfusion, the onset of fever indicates a possible bloodborne infection. Malaria is a protozoal disease transmitted through infected blood, causing symptoms like fever. Toxoplasmosis, Leishmaniasis, and Amebiasis are not typically associated with fever following hemotransfusion. Malaria fits the timeline and mode of transmission in this scenario.

Correct Answer: C

Rationale: The correct answer is C because lymphocytic choriomeningitis virus belongs to the family Arenaviridae. This virus is a well-known member of the Arenaviridae family and is associated with various diseases. Option A is incorrect as Arenaviruses can be isolated from clinical materials using suitable methods. Option B is incorrect because Arenaviruses replicate in the cytoplasm, not the nucleus. Option D is incorrect as Arenaviruses can infect various hosts, not just humans. Therefore, the statement that lymphocytic choriomeningitis virus belongs to the family Arenaviridae is true.

Correct Answer: A

Rationale: The correct answer is A: Spores. In the Ozheshko staining method, spores appear blue with red terminal components. Spores are reproductive structures produced by some bacteria, fungi, and protozoa. Cilia are short, hair-like structures used for movement. Flagella are long, whip-like structures also used for movement. Capsules are outer protective layers surrounding some bacteria. In this case, the description of rod-like microorganisms with blue staining and red terminal components aligns with the characteristics of spores, making it the correct answer.

Correct Answer: D

Rationale: The correct answer is D: Imipenem. Imipenem is a carbapenem antibiotic effective against multiple-resistant microorganisms due to its broad spectrum and resistance to beta-lactamases. It is often used as a last resort for severe infections. Ampicillin (A) and Penicillin (B) are both beta-lactam antibiotics that are less effective against multiple-resistant microorganisms due to widespread resistance mechanisms. Augmentin (C) is a combination of amoxicillin and clavulanic acid, which may have limited efficacy against certain resistant strains but is not as effective as imipenem for treating infections caused by multiple-resistant microorganisms.

Correct Answer: A

Rationale: The correct answer is A: Streptococcus pneumoniae. This bacterium is known for producing a capsule that helps it evade the immune system. The capsule acts as a protective barrier, making it difficult for the immune system to recognize and attack the bacteria. Streptococcus pneumoniae is a common cause of pneumonia and meningitis. Explanation for why other choices are incorrect: B: Escherichia coli does not typically produce a capsule for immune evasion. It is more commonly associated with gastrointestinal infections. C: Salmonella enterica also does not produce a capsule for immune evasion. It is known for causing foodborne illness. D: Bacillus subtilis is a soil bacterium that is not known for producing a capsule to avoid the immune system.

Correct Answer: A

Rationale: The correct answer is A: Entamoeba histolytica. This protozoan parasite causes amoebic dysentery and is characterized by cysts with four nuclei in fecal smears. It is commonly associated with chronic diarrhea. Balantidium coli (B) presents with large ciliated trophozoites, not cysts. Giardia lamblia (C) has trophozoites with flagella and causes giardiasis, not cysts with four nuclei. Trichomonas hominis (D) typically has a pear-shaped trophozoite and is not associated with cysts with four nuclei.

Correct Answer: C

Rationale: The correct answer is C: Vibrio. Cholera is caused by Vibrio cholerae bacteria. These bacteria produce a toxin that causes severe diarrhea and dehydration. Escherichia (choice A) and Salmonella (choice B) are known for causing other types of gastrointestinal infections but not cholera. Acinetobacter (choice D) typically causes respiratory infections, not gastrointestinal illnesses like cholera. Therefore, the correct choice is Vibrio as it is specifically associated with cholera.

Correct Answer: B

Rationale: The correct answer is B: Protein synthesis. Bacterial ribosomes are responsible for translating the genetic information from mRNA into proteins. This process involves the binding of transfer RNA molecules carrying amino acids to the ribosome and the formation of peptide bonds between the amino acids to create proteins. DNA replication (A) is carried out by DNA polymerase enzymes, not ribosomes. Energy production (C) is primarily the function of mitochondria in eukaryotic cells, and cell division (D) is regulated by a complex network of proteins and signaling pathways, not ribosomes.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Escherichia coli, Salmonella enterica, and Pseudomonas aeruginosa are all known to cause urinary tract infections (UTIs) in humans. E. coli is the most common cause of UTIs, accounting for about 80-85% of cases. S. enterica and P. aeruginosa are less common but can still infect the urinary tract under certain circumstances. Therefore, all three bacteria can potentially cause UTIs, making option D the correct choice. Choices A, B, and C are incorrect because they do not cover the full range of bacteria known to cause UTIs.