Which of the following statements concerning Neisseria Meningitidis is correct?
- A. Has no capsules
- B. It causes epidemic meningitis
- C. Grow on differential media
- D. Gram-positive rods
Correct Answer: B
Rationale: The correct answer is B: It causes epidemic meningitis. Neisseria Meningitidis is a bacterium that can cause meningitis, an infection of the protective membranes covering the brain and spinal cord. This bacterium is known to cause outbreaks or epidemics of meningitis, especially in crowded or close-contact settings. The other choices are incorrect because:
A: Neisseria Meningitidis does have a capsule, which helps it evade the immune system.
C: Neisseria Meningitidis grows on selective media like Thayer-Martin agar, not differential media.
D: Neisseria Meningitidis is a Gram-negative diplococcus, not a Gram-positive rod.
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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.
In a bacteriological laboratory some bacterial smears had to be stained by Gram's method. For this purpose the following reagents were prepared: gentian violet, Lugol's solution, aqueous fuchsin solution. What other reagent is required?
- A. 96% ethanol
- B. 5% sulfuric acid
- C. Methylene blue solution
- D. Carbolic fuchsin
Correct Answer: A
Rationale: The correct answer is A: 96% ethanol. In Gram's staining method, after applying gentian violet, Lugol's solution, and aqueous fuchsin, the next step is to use a decolorizing agent like 96% ethanol to wash away the excess stain from the Gram-negative bacteria. This step is crucial as it helps differentiate between Gram-positive and Gram-negative bacteria based on their cell wall properties. The other choices are incorrect because sulfuric acid is not used in Gram's staining method, methylene blue is typically used in other staining techniques like the simple stain, and carbolic fuchsin is not a standard reagent in the Gram's staining process.
Microbiological analysis of medicinal raw materials revealed capsular bacteria. What stain method was used to detect the capsules?
- A. Gin's
- B. Ziehl-Neelsen's
- C. Neisser's
- D. Gram's
Correct Answer: A
Rationale: The correct answer is A: Gin's stain method. Gin's stain method is specifically used to detect capsules of bacteria. This method involves staining the bacteria with crystal violet and copper sulfate, which highlights the capsules as a clear halo around the stained bacterial cells. Ziehl-Neelsen's stain is used for acid-fast bacteria like Mycobacterium tuberculosis, Neisser's stain is for detecting Neisseria species, and Gram's stain is for differentiating bacteria based on their cell wall composition (Gram-positive vs. Gram-negative). Therefore, choices B, C, and D are incorrect for this scenario.
Which bacteria are capable of producing spores that can survive extreme environmental conditions?
- A. Clostridium botulinum
- B. Bacillus anthracis
- C. Both A and B
- D. None of the above
Correct Answer: C
Rationale: The correct answer is C (Both A and B) because both Clostridium botulinum and Bacillus anthracis are capable of producing spores. Spores are highly resistant structures that allow bacteria to survive harsh environmental conditions. Clostridium botulinum and Bacillus anthracis produce spores as a survival mechanism when conditions become unfavorable. Choice A (Clostridium botulinum) is incorrect because it only represents one of the bacteria capable of producing spores. Choice B (Bacillus anthracis) is also incorrect as it alone does not encompass all bacteria capable of producing spores. Choice D (None of the above) is incorrect as both bacteria mentioned can produce spores.
The most rapid rate of drug absorption is achieved by __________ administration.
- A. on the skin
- B. intravenous
- C. intramuscular
- D. sublingual
Correct Answer: B
Rationale: The correct answer is B: intravenous administration. This route bypasses the first-pass metabolism, allowing the drug to directly enter the bloodstream for immediate distribution. In contrast, on the skin (A) and sublingual (D) routes have slower absorption rates due to barriers like skin layers or mucous membranes. Intramuscular (C) absorption is slower than intravenous due to slower perfusion rates in muscle tissues. Overall, intravenous administration provides the fastest and most direct route for drug absorption, making it the most rapid method.