Nokea
Which of the following does NOT describe Cephalosporins
- A. relatively broad spectrum
- B. bactericidal
- C. beta-lactam
- D. interferes with protein synthesis
Correct Answer: D
Rationale: The correct answer is D: interferes with protein synthesis. Cephalosporins are beta-lactam antibiotics that work by inhibiting bacterial cell wall synthesis, not protein synthesis. They are bactericidal and have a relatively broad spectrum of activity against various bacteria. Choice A, B, and C all describe characteristics of cephalosporins, making them incorrect options.
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A patient ill with amebiasis was prescribed a certain drug. The use of alcohol together with this drug is contraindicated because the drug inhibits metabolism of ethyl alcohol. What drug is it?
- A. Metronidazole
- B. Reserpine
- C. Clonidine
- D. Diazepam
Correct Answer: A
Rationale: Rationale:
1. Metronidazole is known to inhibit aldehyde dehydrogenase, an enzyme involved in alcohol metabolism.
2. Inhibition of this enzyme leads to accumulation of acetaldehyde, causing unpleasant symptoms when alcohol is consumed.
3. This reaction is known as the disulfiram-like reaction.
4. Reserpine, Clonidine, and Diazepam do not have this specific mechanism of action.
Summary:
- Option A (Metronidazole) is correct due to its inhibition of alcohol metabolism.
- Options B, C, and D are incorrect as they do not exhibit this interaction with alcohol metabolism.
The most common cause of cystitis (after Escherichia coli) in healthy sexually active women is:
- A. Staphylococcus saprophyticus
- B. Proteus mirabilis
- C. Pseudomonas aeruginosa
- D. Klebsiella pneumoniae
Correct Answer: A
Rationale: The correct answer is A: Staphylococcus saprophyticus. This bacterium is the second most common cause of cystitis in healthy sexually active women after E. coli. Staphylococcus saprophyticus is commonly found in the gastrointestinal and genital areas. It has a unique ability to adhere to uroepithelial cells, making it a common pathogen in urinary tract infections. Proteus mirabilis is more commonly associated with complicated UTIs, especially in catheterized patients. Pseudomonas aeruginosa is more commonly seen in hospitalized or immunocompromised patients. Klebsiella pneumoniae is typically associated with UTIs in elderly patients or those with structural abnormalities in the urinary tract.
A 28 y.o. patient without permanent residence was admitted to the hospital with the preliminary diagnosis influenza. On the fith day of illness he got a maculopapular petechial rash on his body and internal surfaces of extremities. Body temperature is 410 C, euphoria, face hyperemia, sclera reddening, tongue tremor, tachycardia, splenomegaly, excitement. What is the most probable diagnosis?
- A. Epidemic typhus
- B. Delirium alcoholicum
- C. Leptospirosis
- D. Measles
Correct Answer: A
Rationale: Step 1: Initial diagnosis of influenza suggests a viral illness.
Step 2: Presence of maculopapular petechial rash and high fever indicates a systemic infection.
Step 3: Symptoms like euphoria, hyperemia, tachycardia, splenomegaly, and excitement are characteristic of epidemic typhus.
Step 4: Face hyperemia, sclera reddening, and tongue tremor are specific to epidemic typhus.
Step 5: Epidemic typhus is transmitted by body lice, which fits the scenario of a patient without permanent residence.
Summary:
- Delirium alcoholicum is unlikely due to the specific symptoms and lack of history of alcohol abuse.
- Leptospirosis typically presents with jaundice and renal symptoms, not seen in this case.
- Measles rash is different from the maculopapular petechial rash described.
Which bacteria are responsible for causing tuberculosis?
- A. Streptococcus pneumoniae
- B. Mycobacterium tuberculosis
- C. Neisseria meningitidis
- D. Clostridium botulinum
Correct Answer: B
Rationale: The correct answer is B: Mycobacterium tuberculosis. This bacterium is responsible for causing tuberculosis. Mycobacterium tuberculosis specifically targets the lungs, leading to respiratory symptoms and can spread to other parts of the body. Streptococcus pneumoniae (A) is known for causing pneumonia, Neisseria meningitidis (C) causes meningitis, and Clostridium botulinum (D) causes botulism, not tuberculosis. Mycobacterium tuberculosis is the only bacterium among the choices that is associated with tuberculosis.
Which of the following bacteria is responsible for causing peptic ulcers?
- A. Escherichia coli
- B. Helicobacter pylori
- C. Streptococcus pyogenes
- D. Mycobacterium tuberculosis
Correct Answer: B
Rationale: The correct answer is B: Helicobacter pylori. This bacterium is known to be the primary cause of peptic ulcers by colonizing the stomach lining and causing inflammation. It produces urease enzyme to neutralize stomach acid and has a flagellum for mobility. Escherichia coli (A) is mainly associated with foodborne illnesses. Streptococcus pyogenes (C) causes strep throat and skin infections. Mycobacterium tuberculosis (D) causes tuberculosis, a respiratory infection. Therefore, Helicobacter pylori is the correct choice for peptic ulcers based on its unique characteristics and pathogenicity.