mastering microbiology test bank

Correct Answer: A

Rationale: Rationale: 1. Bacillary dysentery primarily affects the intestinal tract, not the bloodstream. 2. Bacteremia is rare in bacillary dysentery, as the infection is localized. 3. Isolating bacteria from the blood is not a typical diagnostic feature. 4. Therefore, the correct answer is A. Summary: Bacteria causing bacillary dysentery are not typically isolated from the patient's blood due to the localized nature of the infection. Choices B and C are incorrect as they suggest specific timeframes, which are not relevant to bacteremia in this context. Choice D is incorrect as bacteremia is not associated with bacillary dysentery.

Correct Answer: A

Rationale: The correct answer is A: Protozoa. Protozoa are eukaryotic microorganisms, meaning they have a true nucleus and membrane-bound organelles. This relates to the question as eukaryotes are organisms with complex cells containing these features. Viruses (B) are non-living entities that require a host cell to replicate, lacking cellular structures. Viroids (C) are smaller than viruses and consist of only RNA, lacking a protein coat. Prions (D) are misfolded proteins causing diseases but are not considered microorganisms nor do they have cellular structure. Thus, protozoa are the only eukaryotic microorganism group among the options.

Correct Answer: B

Rationale: The correct answer is B: Mycobacterium tuberculosis. This bacterium is responsible for causing tuberculosis. Mycobacterium leprae (choice A) causes leprosy, not tuberculosis. Streptococcus pneumoniae (choice C) is known for causing pneumonia, not tuberculosis. Neisseria gonorrhoeae (choice D) is responsible for causing gonorrhea, not tuberculosis. Mycobacterium tuberculosis is the specific bacterium associated with tuberculosis due to its ability to infect the lungs and other organs, leading to the characteristic symptoms of the disease.

Correct Answer: A

Rationale: The correct answer is A: Malaria. The patient's travel history to an endemic area like Tajikistan, along with symptoms of fever with chills, sweating, and hepatosplenomegaly, are classic for malaria. The blood test results show anemia (low RBC and hemoglobin levels), which can occur in malaria due to hemolysis. The presence of eosinophils and lymphocytes are not typical for malaria, but the overall clinical picture fits. Infectious mononucleosis (choice B) typically presents with sore throat, lymphadenopathy, and atypical lymphocytosis, which are not seen in this case. Sepsis (choice C) is characterized by systemic inflammatory response syndrome and organ dysfunction due to infection, which does not align with the symptoms and findings in the case. Typhoid fever (choice D) usually presents with gradual onset of sustained fever, abdominal pain, headache, and constipation, which are not present in this patient

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.