Nokea
Penicillin-resistant, beta-lactamase-producing strains must be detected..
- A. After antibiotic therapy is begun
- B. Before antibiotic therapy is begun
- C. During the antibiotic therapy
- D. No importance for the time of detection
Correct Answer: B
Rationale: The correct answer is B: Before antibiotic therapy is begun. Detecting penicillin-resistant, beta-lactamase-producing strains before antibiotic therapy is crucial to ensure proper treatment. If detected after therapy (choice A), it may lead to treatment failure. Detection during therapy (choice C) may result in delayed or ineffective treatment. Choice D is incorrect as early detection is essential for successful management.
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A 6-year-old child has duodenal ulcer. What antibacterial drug should be co-administered together with metronidazole and De-Nol in order to eradicate Helicobacter pylori infection?
- A. Amoxicillin
- B. Tetracycline
- C. Oleandomycin
- D. Biseptol
Correct Answer: A
Rationale: The correct answer is A: Amoxicillin. Amoxicillin is commonly used in combination therapy with metronidazole and bismuth compounds like De-Nol to eradicate Helicobacter pylori infection in children. Amoxicillin targets the bacterial cell wall synthesis, working synergistically with metronidazole to effectively eradicate the infection. Tetracycline (choice B) is not recommended in children under 8 years old due to potential tooth discoloration. Oleandomycin (choice C) is not commonly used for H. pylori infection. Biseptol (choice D) is a combination of sulfamethoxazole and trimethoprim, not typically used for H. pylori eradication.
The Gram stain is used to differentiate bacteria based on:
- A. Cell shape
- B. Cell wall structure
- C. Flagella composition
- D. Nutrient requirements
Correct Answer: B
Rationale: The Gram stain differentiates bacteria based on cell wall structure. It classifies bacteria into Gram-positive (purple) and Gram-negative (pink) based on the presence of peptidoglycan in the cell wall. This method helps in identifying the bacterial species and determining appropriate treatment. Option A (Cell shape) is incorrect because the Gram stain focuses on cell wall composition, not cell shape. Option C (Flagella composition) is incorrect as the Gram stain does not assess flagella. Option D (Nutrient requirements) is incorrect as it does not relate to the purpose of the Gram stain.
Which of the following pathogens has the widest infectious spectrum
- A. Anthrax bacillus
- B. mumps virus
- C. the causative agent of gonorrhea
- D. the rabies virus
Correct Answer: A
Rationale: The correct answer is A, Anthrax bacillus, because it has the widest infectious spectrum among the options provided. Anthrax bacillus can infect a wide range of hosts, including humans and various animals. It is known for its ability to survive in different environments and cause disease through various routes of exposure. In contrast, choices B, C, and D have more limited infectious spectra. Mumps virus primarily infects humans, the causative agent of gonorrhea mainly affects humans through sexual contact, and the rabies virus typically infects mammals through bites from infected animals. Therefore, Anthrax bacillus is the correct choice due to its broader range of hosts and modes of transmission compared to the other options.
A 34-year-old male visited Tajikistan. After return, he complains of fever up to 40oC which occurs every second day and is accompanied by chills, sweating. Hepatosplenomegaly is present. Blood test results: RBC- 3x1012/l, b- 80 g/l, WBC- 4x109/l, eosinophils - 1%, stab neutrophils - 5%, segmented neutrophils - 60%, lymphocytes - 24%, monocytes - 10%, ESR - 25 mm/h. What is the provisional diagnosis?
- A. Malaria
- B. Infectious mononucleosis
- C. Sepsis
- D. Typhoid fever
Correct Answer: A
Rationale: The correct answer is A: Malaria. The patient's travel history to an endemic area like Tajikistan, along with symptoms of fever with chills, sweating, and hepatosplenomegaly, are classic for malaria. The blood test results show anemia (low RBC and hemoglobin levels), which can occur in malaria due to hemolysis. The presence of eosinophils and lymphocytes are not typical for malaria, but the overall clinical picture fits. Infectious mononucleosis (choice B) typically presents with sore throat, lymphadenopathy, and atypical lymphocytosis, which are not seen in this case. Sepsis (choice C) is characterized by systemic inflammatory response syndrome and organ dysfunction due to infection, which does not align with the symptoms and findings in the case. Typhoid fever (choice D) usually presents with gradual onset of sustained fever, abdominal pain, headache, and constipation, which are not present in this patient
Tuberculosis can be treated by means of combined chemotherapy that includes substances with different mechanisms of action. What antituberculous medication inhibits transcription of RNA into DNA in mycobacteria?
- A. Rifampicin
- B. Isoniazid
- C. Streptomycin
- D. Ethionamide
Correct Answer: A
Rationale: Rifampicin is the correct answer because it inhibits RNA transcription in mycobacteria by binding to the bacterial RNA polymerase. This prevents the synthesis of RNA, leading to the inhibition of protein production essential for bacterial growth.
Isoniazid inhibits mycolic acid synthesis, Streptomycin inhibits protein synthesis, and Ethionamide disrupts mycolic acid synthesis. These mechanisms are different from inhibiting RNA transcription, making them incorrect choices.