Nokea
Which bacteria produce exotoxins that can cause severe gastrointestinal illness?
- A. Clostridium botulinum
- B. Vibrio cholerae
- C. Escherichia coli
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D, All of the above. Clostridium botulinum produces botulinum toxin causing botulism, Vibrio cholerae produces cholera toxin leading to severe diarrhea, and certain strains of Escherichia coli produce toxins causing gastrointestinal illness. Each bacterium has specific exotoxins that can result in severe gastrointestinal symptoms. Therefore, all three choices are correct in producing exotoxins that can cause severe gastrointestinal illness.
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Factors for transmission of nosocomial infections are:
- A. Medical dressings
- B. Breast milk
- C. Toys
- D. All are correct
Correct Answer: D
Rationale: The correct answer is D because all the factors listed can contribute to the transmission of nosocomial infections. Medical dressings can harbor pathogens, breast milk can be a source of infection if not handled properly, and toys can serve as fomites for spreading germs. Choosing any other option would be incorrect as they all play a role in facilitating the transmission of nosocomial infections. It is important to consider all potential sources of infection in healthcare settings to effectively prevent the spread of nosocomial infections.
All of the statements about Rotaviruses are correct EXCEPT
- A. non-specific antiviral therapy is available
- B. Rotaviruses are ubiquitous worldwide
- C. Rotaviruses are a major cause of meningitis
- D. large amounts of viruses are released in fecal matter
Correct Answer: C
Rationale: The correct answer is C because Rotaviruses are not a major cause of meningitis; they primarily cause gastroenteritis. This is because Rotaviruses infect the gastrointestinal tract, not the central nervous system. Choice A is incorrect because there is no specific antiviral therapy for Rotaviruses. Choice B is correct as Rotaviruses are indeed widespread globally. Choice D is correct as Rotaviruses are shed in large amounts in feces, contributing to their ability to spread easily.
Which of the following statements about in vitro cultivation of viruses is true?
- A. Viral cultivation under laboratory conditions is impossible
- B. Viruses are cultured on hen embryos, cell cultures and experimental animals
- C. Viruses are cultivated on special nutrient media
- D. Viruses are cultured only in human embryonic cell cultures
Correct Answer: B
Rationale: The correct answer is B because viruses can indeed be cultured on hen embryos, cell cultures, and experimental animals in vitro. This method allows for the replication and study of viruses outside the host organism. Option A is incorrect as viral cultivation is possible in laboratory settings. Option C is incorrect because while viruses can be grown on nutrient media, it is not the only method. Option D is incorrect as viruses can be cultured in various types of cell cultures, not just human embryonic ones.
Which bacterial structure helps in the movement towards or away from chemical stimuli?
- A. Flagella
- B. Pili
- C. Capsule
- D. Fimbriae
Correct Answer: A
Rationale: Flagella are the correct answer because they are long, whip-like structures that aid in bacterial movement towards or away from chemical stimuli. They rotate like propellers, allowing the bacterium to navigate its environment. Pili are used for attachment, not movement. Capsules are involved in protection and adherence, not chemotaxis. Fimbriae help in attachment to surfaces, not in movement towards stimuli.
Penicillin-resistant, beta-lactamase-producing strains must be detected..
- A. After antibiotic therapy is begun
- B. Before antibiotic therapy is begun
- C. During the antibiotic therapy
- D. No importance for the time of detection
Correct Answer: B
Rationale: The correct answer is B: Before antibiotic therapy is begun. Detecting penicillin-resistant, beta-lactamase-producing strains before antibiotic therapy is crucial to ensure proper treatment. If detected after therapy (choice A), it may lead to treatment failure. Detection during therapy (choice C) may result in delayed or ineffective treatment. Choice D is incorrect as early detection is essential for successful management.