Nokea
An 18-year-old patient has developed candidiasis after the case of pneumonia treated with β-lactam antibiotic. What antimycotic agent should be prescribed?
- A. Fluconazole
- B. Streptomycin
- C. Phthalylsulfathiazole
- D. Ampicillin
Correct Answer: A
Rationale: The correct answer is A: Fluconazole.
1. Fluconazole is an antifungal agent effective against Candida species commonly causing candidiasis.
2. Streptomycin (B) is an antibiotic used for bacterial infections, not fungal.
3. Phthalylsulfathiazole (C) is an antibacterial agent, not antifungal.
4. Ampicillin (D) is a β-lactam antibiotic, which can actually contribute to fungal infections like candidiasis.
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A 32 year old patient complains about heartburn and dull pain in the epigastrium that appear 2-3 hours after meal. Exacerbations happen in spring and in autumn. The patient has food intolerance of eggs and fish. Objectively: stomach palpation reveals painfulness in the gastroduodenal area. Electrophasoduodenoscopy revealed a 5 mm ulcer on the anterior wall of duodenum. Urease test is positive. What is the most probable leading mechanism of disease development?
- A. Helicobacterial infection
- B. Dietary allergy
- C. Autoantibody production
- D. Reduced prostaglandin synthesis
Correct Answer: A
Rationale: The correct answer is A: Helicobacterial infection. This is the most probable leading mechanism of disease development in this case because the patient's symptoms, such as heartburn, epigastric pain, food intolerance, and presence of a duodenal ulcer with a positive urease test, are classic signs of Helicobacter pylori infection. This bacterium colonizes the stomach lining, leading to inflammation and ulcer formation. The exacerbations in spring and autumn could be due to seasonal variations in immune response.
Choice B: Dietary allergy is incorrect because the symptoms and findings in the patient are more indicative of an infectious etiology rather than an allergic reaction to specific foods.
Choice C: Autoantibody production is unlikely as there are no indications of an autoimmune process in this case.
Choice D: Reduced prostaglandin synthesis is not the leading mechanism as the symptoms and findings are more consistent with an infectious cause rather than a deficiency in prostaglandin synthesis.
A blood culture from a patient with sepsis revealed Gram-positive cocci in pairs. The bacteria were catalase-negative and alpha-hemolytic. What is the most likely causative agent?
- A. Streptococcus pneumoniae
- B. Staphylococcus aureus
- C. Enterococcus faecalis
- D. Neisseria gonorrhoeae
Correct Answer: A
Rationale: The correct answer is A: Streptococcus pneumoniae. This is because the bacterium is Gram-positive cocci in pairs, catalase-negative, and alpha-hemolytic, which are characteristic features of S. pneumoniae. The other choices can be ruled out based on specific characteristics: B) Staphylococcus aureus is catalase-positive, C) Enterococcus faecalis is gamma-hemolytic, and D) Neisseria gonorrhoeae is a Gram-negative diplococcus. Therefore, based on the given information, S. pneumoniae is the most likely causative agent of the sepsis.
Which of the following bacteria is associated with stomach ulcers?
- A. Escherichia coli
- B. Helicobacter pylori
- C. Bacillus cereus
- D. Clostridium difficile
Correct Answer: B
Rationale: The correct answer is B: Helicobacter pylori. This bacterium is associated with stomach ulcers as it can survive in the acidic environment of the stomach and produce substances that weaken the stomach lining. Escherichia coli (A) is associated with foodborne illnesses, not ulcers. Bacillus cereus (C) causes food poisoning. Clostridium difficile (D) is associated with antibiotic-associated colitis, not ulcers. Therefore, Helicobacter pylori is the correct answer based on its specific association with stomach ulcers.
Gram-negative rods producing blue-green pigment and a fruity odor were isolated from a wound infection. What is the causative agent?
- A. Pseudomonas aeruginosa
- B. Proteus mirabilis
- C. Klebsiella pneumoniae
- D. Escherichia coli
Correct Answer: A
Rationale: The correct answer is A: Pseudomonas aeruginosa. P. aeruginosa is known for producing a blue-green pigment called pyocyanin, which gives a characteristic color to the colonies. The fruity odor is due to the production of a compound called 2-aminoacetophenone by P. aeruginosa. These features are classic for P. aeruginosa and help differentiate it from other Gram-negative rods. Proteus mirabilis (B) typically does not produce blue-green pigment or fruity odor. Klebsiella pneumoniae (C) and Escherichia coli (D) also do not exhibit these specific characteristics associated with P. aeruginosa.
The organism often called “flesh-eating bacteria†is:
- A. Staphylococcus aureus
- B. Staphylococcus epidermidis
- C. Streptococcus pyogenes
- D. Propionibacterium acnes
Correct Answer: C
Rationale: The correct answer is C: Streptococcus pyogenes. This bacterium is commonly known as "flesh-eating bacteria" due to its ability to cause severe tissue destruction and necrotizing fasciitis. Streptococcus pyogenes produces toxins that break down skin and muscle tissues. Staphylococcus aureus (A) can cause skin infections but is not typically associated with necrotizing fasciitis. Staphylococcus epidermidis (B) is a normal skin flora and rarely causes infections. Propionibacterium acnes (D) is associated with acne and not known for causing tissue destruction. Therefore, the correct choice is Streptococcus pyogenes due to its unique ability to cause severe tissue damage and necrotizing fasciitis.