Native microscopic slides are good for observation of:
- A. Motility
- B. Division
- C. Presence of capsules
- D. None of the above
Correct Answer: A
Rationale: The correct answer is A: Motility. Native microscopic slides are ideal for observing motility because they allow for the observation of living microorganisms in their natural state. By observing the movement of microorganisms on a native slide, one can assess their motility characteristics accurately.
Choice B (Division) is incorrect because native slides may not provide the ideal conditions for observing cell division, as it may be difficult to capture the exact moment of division in a live organism.
Choice C (Presence of capsules) is also incorrect because observing capsules usually requires specific staining techniques that may not be suitable for native slides.
Choice D (None of the above) is incorrect as native slides are indeed beneficial for observing motility.
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What clinical specimen can be analysed in the diagnosis of sexually transmitted infections:
- A. Genital ulcer secretion
- B. Lymph node punctate
- C. Serum
- D. All are correct
Correct Answer: D
Rationale: Certainly! The correct answer is D because all three options (A, B, and C) can be analyzed in the diagnosis of sexually transmitted infections. Genital ulcer secretions can reveal the presence of pathogens causing STIs, lymph node punctate can indicate systemic infection, and serum can be tested for specific STI antibodies. Therefore, all these clinical specimens are essential for a comprehensive diagnosis of sexually transmitted infections. The other choices (A, B, C) are incorrect as they individually represent important specimens used in the diagnosis process.
Which is not true?
- A. Interferon beta is produced by the fibroblasts
- B. Interferon alpha is produced by the leukocytes
- C. Interferon gamma is produced by the lymphocytes
- D. Interferon delta is produced by the macrophages
Correct Answer: D
Rationale: Interferon delta is not a known type of interferon, making choice D incorrect. Interferon beta is indeed produced by fibroblasts (choice A), interferon alpha by leukocytes (choice B), and interferon gamma by lymphocytes (choice C). Each type of interferon is produced by specific cells in the immune system, contributing to the body's defense against viruses and other pathogens.
The cell surface of pathogenic gram-negative bacteria can be covered in villi and cilia. What function do these structures have?
- A. RNA exchange between cells
- B. Inhibition of complement activity
- C. Bacterial adhesion to the surface of the host cells, conjugation
- D. Resistance to antibody opsonization
Correct Answer: C
Rationale: The correct answer is C: Bacterial adhesion to the surface of the host cells, conjugation. Villi and cilia on the cell surface of pathogenic bacteria help in bacterial adhesion to host cells, facilitating the process of infection. Conjugation is the transfer of genetic material between bacterial cells, which can be aided by these structures. The other choices are incorrect because RNA exchange between cells (A) is typically facilitated by different structures like pili, inhibition of complement activity (B) is not related to the function of villi and cilia, and resistance to antibody opsonization (D) is usually achieved through other mechanisms such as capsule formation.
During bacteriological examination of the purulent discharge obtained from a postoperative wound an inoculation on meat infusion agar has been performed. The inoculation has resulted in large colorless mucous colonies that in 24 hours with exposure to sunlight developed green-blue pigmentation and smell of honey or jasmine. Bacterioscopy revealed gram-negative lophotrichea. What bacterial culture is contained in purulent discharge?
- A. Pseudomonas aeruginosa
- B. Proteus vulgaris
- C. Klebsiella osaenae
- D. Streptomyces griseus
Correct Answer: A
Rationale: The correct answer is A: Pseudomonas aeruginosa. Pseudomonas aeruginosa is a gram-negative bacterium known for its green-blue pigmentation and sweet, fruity odor. The large colorless mucous colonies that develop green-blue pigmentation and honey or jasmine smell point towards Pseudomonas aeruginosa. The bacterioscopy revealing gram-negative lophotrichea further supports this identification. Proteus vulgaris and Klebsiella osaenae do not typically exhibit the described characteristics. Streptomyces griseus is a soil bacterium known for its antibiotic production and is not commonly associated with wound infections.
A 45-year-old patient complains of body temperature rise up to 40oC, general weakness, headache, painfulness and spastic muscle contractions around the wound in the shin. He received this wound 5 days ago when working in his garden. He requested no medical care back then. What wound infection can be suspected?
- A. Tetanus
- B. Anthrax
- C. Erysipelas
- D. Gram-positive
Correct Answer: A
Rationale: The correct answer is A: Tetanus. The patient's symptoms of muscle contractions, fever, and wound history suggest tetanus, caused by Clostridium tetani bacteria commonly found in soil. The spastic muscle contractions around the wound are classic for tetanus due to the neurotoxin produced by the bacteria. General weakness and headache are also common symptoms.
B: Anthrax is unlikely as it presents with different symptoms such as skin lesions, respiratory symptoms, and gastrointestinal symptoms.
C: Erysipelas is characterized by red, swollen patches on the skin, not consistent with the symptoms described.
D: Gram-positive is not a specific diagnosis but a broad category of bacteria. Tetanus is caused by Clostridium tetani, which is a Gram-positive bacterium, but this choice does not provide a specific infection diagnosis.