Nokea
How is viral multiplication detected in cell culture?
- A. by the presence of a specific cytopathic effect
- B. by using an immunofluorescence detection method
- C. the characteristic type of viral colonies
- D. A and B both
Correct Answer: D
Rationale: The correct answer is D because viral multiplication in cell culture can be detected by observing a specific cytopathic effect (A) caused by viral infection in cells and by using an immunofluorescence detection method (B) to visualize viral antigens within the cells. Choice C, the characteristic type of viral colonies, is incorrect as viral multiplication is not typically detected by observing viral colonies in cell culture. Option D is the correct choice as both A and B methods are commonly used to detect viral multiplication in cell culture.
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Prophylaxis of smallpox and revaccination is performed:
- A. Every year after the first vaccine
- B. Every second year
- C. Every three years
- D. No revaccination is needed, just the initial vaccine is enough
Correct Answer: D
Rationale: The correct answer is D because smallpox vaccination provides long-lasting immunity, often for a lifetime. Revaccination is not necessary as the initial vaccine confers sufficient protection. Choice A is incorrect because yearly revaccination is unnecessary and excessive. Choice B and C are also incorrect as there is no need for revaccination every second or third year. The key is to understand that smallpox vaccination typically provides lifelong immunity, making ongoing revaccination unnecessary.
Bacterial spores are used for:
- A. Protection against phagocytosis
- B. Reproduction
- C. Survival
- D. Nutrient storage
Correct Answer: C
Rationale: The correct answer is C: Survival. Bacterial spores are specialized structures that bacteria form to survive harsh conditions such as extreme temperatures or lack of nutrients. Spores are not used for protection against phagocytosis (A) as they are dormant structures and not actively involved in defense mechanisms. They are not for reproduction (B) as spores are a form of bacterial reproduction but not the primary purpose of spore formation. Spores do not serve as nutrient storage (D) as they are mainly used for survival during unfavorable conditions.
Which bacteria are responsible for causing the disease tuberculosis?
- A. Mycobacterium leprae
- B. Streptococcus pneumoniae
- C. Mycobacterium tuberculosis
- D. Clostridium botulinum
Correct Answer: C
Rationale: The correct answer is C: Mycobacterium tuberculosis. This bacterium is responsible for causing tuberculosis as it specifically infects the lungs and can spread to other parts of the body. Mycobacterium leprae (A) causes leprosy, Streptococcus pneumoniae (B) causes pneumonia, and Clostridium botulinum (D) causes botulism, making them incorrect choices for tuberculosis. Mycobacterium tuberculosis has unique characteristics and mechanisms that enable it to cause tuberculosis, such as its ability to evade the immune system and form granulomas in the lungs.
Patients with similar complaints applied to the doctor: weakness, pain in the intestines, disorder of GIT. Examination of the feces revealed that one patient with four nucleus cysts should be hospitalized immediately. For what protozoa are such cysts typical?
- A. Lamblia
- B. Dysenteric amoeba
- C. Balantidium
- D. Trichomonas
Correct Answer: B
Rationale: The correct answer is B: Dysenteric amoeba.
1. Dysenteric amoeba causes amoebiasis, which presents with symptoms like weakness, intestinal pain, and gastrointestinal disorders.
2. The presence of four-nucleus cysts in the feces indicates an infection with Entamoeba histolytica, the causative agent of amoebiasis.
3. Multiple-nucleus cysts are characteristic of Entamoeba histolytica, distinguishing it from other protozoa.
4. Lamblia (choice A), Balantidium (choice C), and Trichomonas (choice D) are not associated with four-nucleus cysts or the mentioned symptoms, making them incorrect choices.
A patient has food poisoning. Laboratory analysis revealed a culture of anaerobic gram-positive spore-forming bacteria. What is the most likely kind of the isolated causative agent?
- A. C. perfringens
- B. Proteus vulgaris
- C. P. mirabilis
- D. Vibrio parahemolyticus
Correct Answer: A
Rationale: The correct answer is A: C. perfringens. This is because Clostridium perfringens is a gram-positive, anaerobic, spore-forming bacterium commonly associated with food poisoning. It produces toxins that cause gastrointestinal symptoms. Proteus vulgaris (B) and P. mirabilis (C) are gram-negative bacteria not typically associated with food poisoning. Vibrio parahemolyticus (D) is a gram-negative bacterium causing seafood-related gastroenteritis, not spore-forming or anaerobic.