Nokea
A patient with suspicion on epidemic typhus was admitted to the hospital. Some arachnids and insects have been found in his flat. Which of them may be a carrier of the pathogen of epidemic typhus?
- A. Lice
- B. Spiders
- C. Bed-bugs
- D. Cockroaches
Correct Answer: A
Rationale: The correct answer is A: Lice. Lice, specifically body lice (Pediculus humanus corporis), are known carriers of the pathogen Rickettsia prowazekii, which causes epidemic typhus. Body lice are commonly found in unsanitary conditions and can transmit the bacteria through their bites. Spiders (choice B), bed-bugs (choice C), and cockroaches (choice D) are not known vectors of epidemic typhus. Spiders are predators that do not transmit diseases to humans, while bed-bugs and cockroaches are associated with other health issues but not epidemic typhus transmission.
You may also like to solve these questions
Which bacteria are responsible for causing pneumonia?
- A. Streptococcus pneumoniae
- B. Mycobacterium tuberculosis
- C. Pseudomonas aeruginosa
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D (All of the above) because different bacteria can cause pneumonia. Streptococcus pneumoniae is the most common cause of community-acquired pneumonia. Mycobacterium tuberculosis causes tuberculosis, which can lead to pneumonia. Pseudomonas aeruginosa is a common cause of hospital-acquired pneumonia. Therefore, all three bacteria can be responsible for causing pneumonia in different contexts. Choices A, B, and C are incorrect because each bacterium individually can cause pneumonia, so selecting only one option would not cover the full spectrum of bacterial causes of pneumonia.
Which of the following bacteria produce a neurotoxin that affects the nervous system?
- A. Clostridium botulinum
- B. Clostridium tetani
- C. Both A and B
- D. None of the above
Correct Answer: C
Rationale: Rationale: Both Clostridium botulinum and Clostridium tetani produce neurotoxins. Botulinum toxin affects the nervous system by blocking neurotransmitter release, causing paralysis. Tetanus toxin affects the nervous system by interfering with neurotransmitter release, leading to muscle stiffness and spasms. Therefore, Choice C is correct. Choices A and B alone are incorrect because they only mention one of the bacteria that produces a neurotoxin. Choice D is incorrect because both bacteria mentioned in Choices A and B produce neurotoxins.
Gram-negative, capsulated bacteria with capsule, lactose-positive colonies. Isolated for the first time in pneumonia, but have more important role in urinary infections, otitis, meningitides, sepsis, nosocomial infections:
- A. Staphylococcus aureus
- B. Klebsiella pneumonia
- C. Streptococcus pneumoniae
- D. Mycobacterium tuberculosis
Correct Answer: B
Rationale: The correct answer is B: Klebsiella pneumoniae. This bacterium is gram-negative, capsulated, and forms lactose-positive colonies. It was first isolated in pneumonia but is more commonly associated with urinary infections, otitis, meningitides, sepsis, and nosocomial infections. Klebsiella pneumoniae fits all the characteristics mentioned in the question, making it the correct choice.
Incorrect choices:
A: Staphylococcus aureus is gram-positive and does not have a capsule.
C: Streptococcus pneumoniae is also gram-positive and does not fit the description given.
D: Mycobacterium tuberculosis is an acid-fast bacterium associated with tuberculosis, but it is neither gram-negative nor lactose-positive.
Which of the following bacteria is capable of producing an endotoxin that can lead to septic shock?
- A. Escherichia coli
- B. Salmonella enterica
- C. Pseudomonas aeruginosa
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D: All of the above.
1. Escherichia coli can produce endotoxin due to its lipopolysaccharide component.
2. Salmonella enterica also produces endotoxin as part of its cell wall structure.
3. Pseudomonas aeruginosa is known to produce endotoxin as well.
Therefore, all of these bacteria are capable of producing endotoxin, which can trigger an excessive immune response leading to septic shock. Other choices are incorrect because they do not cover all the bacteria mentioned in the question that are capable of producing endotoxin.
In the South and Central America there can be found a species of trypanosomes that is the causative agent of Chagas disease. What animal is the infection carrier specific to this disease?
- A. Triatomine bug
- B. Mosquito
- C. Tsetse fly
- D. Cockroach
Correct Answer: A
Rationale: The correct answer is A: Triatomine bug. Triatomine bugs, also known as "kissing bugs," are the specific carrier of the trypanosomes that cause Chagas disease. These bugs transmit the parasite through their feces, which contain the infectious forms of the trypanosomes. When the bug bites a human or animal, it defecates near the bite wound, allowing the parasites to enter the bloodstream through the broken skin. Mosquitoes (B) transmit diseases like malaria and dengue fever, not Chagas disease. Tsetse flies (C) are known for transmitting African trypanosomiasis (sleeping sickness), not Chagas disease. Cockroaches (D) are not known to transmit Chagas disease.