Nokea
Antibiotics are distributed into following groups:
- A. Blockaders of protein synthesis
- B. Blockaders of cell wall synthesis
- C. Alternators of bacterial cytoplasm
- D. Nothing from above
Correct Answer: A
Rationale: The correct answer is A: Blockaders of protein synthesis because antibiotics in this group target bacterial ribosomes, preventing protein synthesis. This disrupts bacterial growth and replication. Choice B is incorrect as cell wall synthesis inhibitors target a different bacterial component. Choice C is incorrect as antibiotics do not alter bacterial cytoplasm. Choice D is incorrect as antibiotics do fall into different categories based on their mechanism of action.
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Gram-positive spore-forming bacilli were extracted in anoxic environment from the patient's wound contaminated with soil. Cultivation on a blood-glucose agar resulted in growth of the colonies surrounded with hemolysis zone. What agent was extracted from the wound?
- A. Clostridium perfringens
- B. Clostridium botulinum
- C. Staphylococcus aureus
- D. Pseudomonas aeruginosa
Correct Answer: A
Rationale: The correct answer is A: Clostridium perfringens. Clostridium perfringens is a gram-positive spore-forming bacillus commonly found in soil. It produces hemolysis on blood agar, as described in the question. Clostridium botulinum is also a gram-positive spore-forming bacillus, but it does not typically cause hemolysis. Staphylococcus aureus is a gram-positive cocci, not a bacillus. Pseudomonas aeruginosa is a gram-negative bacterium, not a gram-positive spore-forming bacillus.
The catarrhal stage of the whooping cough is characterized by:
- A. Decrease in paroxysms of coughing
- B. Subsequent respiratory infection for many months after the onset of pertussis
- C. Uncontrollable coughing followed by a high pitched 'whoop' sound
- D. Mild respiratory symptoms (mild coughing, sneezing or a runny nose)
Correct Answer: D
Rationale: The correct answer is D because the catarrhal stage of whooping cough is characterized by mild respiratory symptoms such as mild coughing, sneezing, or a runny nose. During this stage, the cough may start to worsen but is not yet severe.
A: Incorrect - Decrease in paroxysms of coughing is not seen in the catarrhal stage; it occurs later in the paroxysmal stage.
B: Incorrect - Subsequent respiratory infection for many months after the onset of pertussis is not a characteristic of the catarrhal stage.
C: Incorrect - Uncontrollable coughing followed by a high pitched 'whoop' sound is typical of the paroxysmal stage, not the catarrhal stage.
After a prolonged isoniazid treatment, the patient developed polyneuritis, paresthesia, memory disorders, and convulsions. What is the most likely mechanism of the described isoniazid side-effects?
- A. Disruption of cell membrane synthesis
- B. Inhibition of protein synthesis
- C. Inhibition of RNA-synthesis
- D. Inhibition of pyridoxal phosphate synthesis
Correct Answer: D
Rationale: The correct answer is D. Isoniazid inhibits pyridoxal phosphate synthesis, which is the active form of vitamin B6. Pyridoxal phosphate is essential for various enzymatic reactions, including neurotransmitter synthesis and myelin formation. Therefore, isoniazid-induced pyridoxal phosphate deficiency can lead to neurological symptoms like polyneuritis, paresthesia, memory disorders, and convulsions.
A: Disruption of cell membrane synthesis - This is not the mechanism of isoniazid side-effects.
B: Inhibition of protein synthesis - Isoniazid does not directly inhibit protein synthesis.
C: Inhibition of RNA-synthesis - Isoniazid does not inhibit RNA synthesis; it affects vitamin B6 metabolism.
Congenital CMV infections are caused by:
- A. coronavirus
- B. herpes simplex virus
- C. cytomegalovirus
- D. Epstein-Barr virus
Correct Answer: C
Rationale: The correct answer is C: cytomegalovirus (CMV). Congenital CMV infections are caused by the transmission of CMV from a pregnant woman to her fetus. CMV is a type of herpes virus, not a coronavirus (A), herpes simplex virus (B), or Epstein-Barr virus (D). CMV is known to cause serious health issues in newborns, making it crucial to identify and manage during pregnancy.
How soon do symptoms typically appear after a person is infected with rabies virus
- A. 48 hours
- B. 1 week
- C. 1 month
- D. 1-2 years
Correct Answer: D
Rationale: The correct answer is D: 1-2 years. Rabies has a long incubation period before symptoms appear due to the slow progression of the virus within the body. The virus travels along nerve fibers to the brain, which can take months to years. During this time, the virus replicates and spreads, eventually leading to symptoms. Choices A, B, and C are incorrect as they underestimate the incubation period of rabies. Symptoms typically do not appear as early as 48 hours, 1 week, or 1 month after infection with the rabies virus.