Nokea
A blood culture from a patient with sepsis revealed Gram-negative diplococci. The organism was oxidase-positive and fermentative. What is the most likely causative agent?
- A. Neisseria gonorrhoeae
- B. Neisseria meningitidis
- C. Haemophilus influenzae
- D. Moraxella catarrhalis
Correct Answer: B
Rationale: The correct answer is B: Neisseria meningitidis. This is because Neisseria meningitidis is a Gram-negative diplococci that is oxidase-positive and fermentative. Neisseria gonorrhoeae (choice A) is also a Gram-negative diplococci but is not fermentative. Haemophilus influenzae (choice C) is not a diplococci and Moraxella catarrhalis (choice D) is oxidase-negative. Thus, Neisseria meningitidis fits all the criteria provided in the question, making it the most likely causative agent for the sepsis in this patient.
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Micrographia, a publication illustrating insects, sponges, as well as plant cells, was published by
- A. Robert Hooke
- B. Antony van Leeuwenhoek
- C. Hans Janssen
- D. John Needham
Correct Answer: A
Rationale: The correct answer is A: Robert Hooke. Hooke published Micrographia in 1665, showcasing detailed illustrations of insects, sponges, and plant cells under the microscope. Hooke's work was groundbreaking in advancing the field of microscopy. Van Leeuwenhoek is known for discovering microorganisms but did not publish Micrographia. Janssen and Needham were not associated with Micrographia. Therefore, A is the correct answer.
Name the halogen-containing antiseptic with fungicidal properties, which is used to treat dermatomycosis:
- A. Iodine solution
- B. Formalin solution
- C. Methylene blue
- D. Brilliant green
Correct Answer: A
Rationale: Rationale:
1. Iodine solution contains iodine, a halogen with antiseptic properties.
2. Iodine is effective against fungi, making it suitable for treating dermatomycosis.
3. Iodine solution is commonly used in dermatology for its fungicidal properties.
4. Formalin, methylene blue, and brilliant green do not contain halogens or have fungicidal properties.
Summary:
- Formalin is a disinfectant, not an antiseptic for dermatomycosis.
- Methylene blue is an antifungal dye, not used as an antiseptic.
- Brilliant green is an antiseptic, but does not contain halogens or have fungicidal properties.
Immunity after single vaccination against tetanus - application of tetanus toxoid is:
- A. intense and usually life long
- B. of limited duration, booster vaccinations are needed
- C. infectious (non-sterile)
- D. no correct answer
Correct Answer: B
Rationale: The correct answer is B. Immunity after a single tetanus vaccination is of limited duration, usually around 10 years. Booster vaccinations are needed to maintain protection due to waning immunity over time. Choice A is incorrect as immunity is not usually lifelong. Choice C is incorrect as tetanus toxoid is a sterile vaccine and does not cause infection. Choice D is also incorrect as there is a correct answer, which is B.
A fecal sample from a patient with diarrhea was cultured on Endo agar, resulting in colorless colonies. The bacteria were Gram-negative rods. What microorganism is most likely?
- A. Salmonella
- B. Shigella
- C. Escherichia coli
- D. Proteus
Correct Answer: B
Rationale: The correct answer is B: Shigella. On Endo agar, Shigella appears as colorless colonies due to its inability to ferment lactose. Shigella is a Gram-negative rod and is a common cause of diarrhea. Salmonella (A) and Escherichia coli (C) would typically produce pink colonies on Endo agar as they can ferment lactose. Proteus (D) is not commonly associated with diarrhea and would not be expected to grow on Endo agar.
A patient suffers from severe postoperative pseudomonadous infection. What of the following antibiotics should be administered in this case?
- A. Amicacin sulfate
- B. Benzylpenicillin
- C. Cephazolin
- D. Erythromycin
Correct Answer: A
Rationale: The correct answer is A: Amikacin sulfate. Pseudomonas aeruginosa is commonly resistant to many antibiotics, but aminoglycosides like Amikacin have good activity against it. Step 1: Identify the pathogen causing the infection. Step 2: Consider the antibiotic's spectrum of activity against the pathogen. Step 3: Choose an antibiotic with proven efficacy. Amikacin is a good choice due to its effectiveness against Pseudomonas. Choice B, Benzylpenicillin, is a penicillin which is not effective against Pseudomonas. Choice C, Cephazolin, is a cephalosporin with limited activity against Pseudomonas. Choice D, Erythromycin, is a macrolide which is not effective against Pseudomonas.