Nokea
How is detected viral multiplication in cell culture
- A. by the presence of a specific cytopathic effect
- B. by using of 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 (A and B both). In viral multiplication, the presence of a specific cytopathic effect (CPE) in cell culture indicates viral replication. This is detected visually through changes in cell morphology. Additionally, immunofluorescence detection methods can be used to detect viral antigens within infected cells, confirming viral multiplication. Options C is incorrect as viral colonies are not typically used to detect viral multiplication in cell culture. Option B alone is not sufficient as it only focuses on immunofluorescence detection, while option A alone may not always be specific. Therefore, the combination of A and B provides a more comprehensive and accurate detection method for viral multiplication in cell culture.
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A patient with pneumonia had sputum cultured on Endo agar, revealing red colonies. The bacteria were Gram-negative rods. What is the most likely causative agent?
- A. Escherichia coli
- B. Klebsiella pneumoniae
- C. Pseudomonas aeruginosa
- D. Proteus mirabilis
Correct Answer: A
Rationale: Rationale for correct answer (A: Escherichia coli):
1. Endo agar selects for Gram-negative bacteria.
2. Red colonies on Endo agar indicate lactose fermentation, characteristic of E. coli.
3. E. coli is a common cause of pneumonia, especially in immunocompromised patients.
Summary of why other choices are incorrect:
- B: Klebsiella pneumoniae: Typically forms mucoid colonies on agar.
- C: Pseudomonas aeruginosa: Produces characteristic greenish-blue colonies on agar.
- D: Proteus mirabilis: Does not typically ferment lactose, so would not produce red colonies on Endo agar.
A patient presented with a painful, swollen lymph node, and bacteremia. A Gram-negative rod with a characteristic safety pin appearance was observed. What is the causative agent?
- A. Yersinia pestis
- B. Clostridium tetani
- C. Brucella melitensis
- D. Pasteurella multocida
Correct Answer: A
Rationale: Step 1: Gram-negative rod with safety pin appearance indicates bipolar staining.
Step 2: Yersinia pestis is a Gram-negative rod causing bubonic plague.
Step 3: Y. pestis has bipolar staining due to its unique F1 capsule.
Step 4: The swollen lymph node and bacteremia are consistent with bubonic plague.
Step 5: Therefore, the correct answer is A: Yersinia pestis.
Summary:
- B: Clostridium tetani causes tetanus, not characterized by a safety pin appearance.
- C: Brucella melitensis causes brucellosis, not characterized by a safety pin appearance.
- D: Pasteurella multocida causes animal bites infections, not characterized by a safety pin appearance.
Crude herbal drugs must be examined for yeast-like fungi. What agar can ensure development of these microorganisms so that associating microflora will grow very slowly or won't grow at all?
- A. Sabouraud's peptone agar
- B. Endo agar
- C. Milk-salt agar
- D. Meat infusion agar
Correct Answer: A
Rationale: The correct answer is A: Sabouraud's peptone agar. This agar is specifically designed for the isolation of yeast and molds due to its low pH and high sugar content, creating an environment conducive for their growth. Yeast-like fungi thrive in this selective medium, while inhibiting the growth of bacteria and other contaminants.
Summary:
- Sabouraud's peptone agar is ideal for cultivating yeast-like fungi.
- Endo agar is used for isolation of gram-negative bacteria, not fungi.
- Milk-salt agar is used for lactobacilli and streptococci, not fungi.
- Meat infusion agar is a general-purpose medium for cultivation of a wide range of microorganisms, not specifically for yeast-like fungi.
Methods typically used to diagnose bacterial infections of the reproductive system include:
- A. microscopic examination of discharge from infected organ and microscopic examination of urine for organisms
- B. biopsy of infected tissue and use of selective media
- C. microscopic examination of fecal sample and protein test of urine
- D. antibody agglutination test and coagulation test
Correct Answer: A
Rationale: Step-by-step rationale for choice A being correct:
1. Microscopic examination of discharge from infected organ allows direct visualization of bacteria causing the infection.
2. Microscopic examination of urine for organisms can help identify any bacteria present in the urinary tract.
3. Both methods are specific for diagnosing bacterial infections in the reproductive system.
Summary:
- Choice B is incorrect as biopsy is invasive and not typically used for diagnosing bacterial infections.
- Choice C is incorrect as fecal samples and urine protein tests are not relevant for diagnosing bacterial infections in the reproductive system.
- Choice D is incorrect as antibody agglutination and coagulation tests are not primary methods for diagnosing bacterial infections in the reproductive system.
For the specific prophylaxis of rabies it is NOT CORRECT that
- A. Ab against rabies virus can be found 14-15 days after immunization
- B. Reinfection is not possible
- C. HRIG (human rabies immunoglobulin) is applied in the first few hours after possible infection
- D. Six (5+1) doses of an inactivated vaccine are applied
Correct Answer: B
Rationale: The correct answer is B because reinfection is indeed possible with rabies virus. Step 1: Reinfection occurs if a person is exposed to the virus again after initial infection. Step 2: Once infected, the virus can remain dormant in the body and become active upon re-exposure. Step 3: Therefore, it is essential to continue preventive measures even after initial immunization. Summary: Choices A, C, and D are incorrect because antibodies develop within 14-15 days post-immunization, HRIG is administered shortly after exposure, and a specific vaccination schedule is followed for rabies prophylaxis, respectively.