Nokea
DNA transfer from one bacterium to another through phages is termed as:
- A. Transfection
- B. Transduction
- C. Induction
- D. Infection
Correct Answer: B
Rationale: The correct answer is B: Transduction. In bacterial genetics, transduction refers to the process of DNA transfer from one bacterium to another via bacteriophages. During transduction, the bacteriophage infects a bacterium, incorporating bacterial DNA into its own genome, which is then transferred to another bacterium upon infecting it.
Rationale:
A: Transfection is the process of introducing foreign DNA into eukaryotic cells, not bacteria.
C: Induction is the process of activating gene expression in a cell.
D: Infection is a general term for the invasion of pathogens into a host organism, not specific to DNA transfer via phages in bacteria.
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Which one of the following microbiological diagnostic methods is the most suitable for detection of genitourinary chlamydiosis
- A. cultural diagnostic
- B. ELISA
- C. CFT
- D. PCR
Correct Answer: D
Rationale: The correct answer is D: PCR. PCR (Polymerase Chain Reaction) is the most suitable method for detecting genitourinary chlamydiosis due to its high sensitivity and specificity in detecting the genetic material of Chlamydia trachomatis. PCR can detect even low levels of the pathogen, providing accurate results.
A: Cultural diagnostic is not as sensitive as PCR and may take longer to produce results.
B: ELISA detects antibodies, which may not be present in early stages of infection, leading to false-negative results.
C: CFT (Complement Fixation Test) is an older method with lower sensitivity compared to PCR for detecting chlamydiosis.
A patient's preliminary diagnosis is toxoplasmosis. What material was used for diagnostics of this disease?
- A. Blood
- B. Feces
- C. Urine
- D. Duodenal contents
Correct Answer: A
Rationale: The correct answer is A: Blood. Toxoplasmosis is diagnosed through serological tests that detect specific antibodies in the blood. These antibodies indicate exposure to the Toxoplasma gondii parasite. Feces, urine, and duodenal contents are not typically used for diagnosing toxoplasmosis as the parasite is not commonly found in these samples. Blood is the primary material used as it provides the necessary antibodies for accurate diagnosis.
The incubation period for hepatitis B is:
- A. One week - 10 days
- B. One month - 45 days
- C. Up to 3 months
- D. Up to 6 months
Correct Answer: C
Rationale: The correct answer is C: Up to 3 months. Hepatitis B has an average incubation period of 60-90 days, which aligns with the timeframe of up to 3 months. This period refers to the time between exposure to the virus and the onset of symptoms. One week to 10 days (choice A) is too short for hepatitis B, as it typically takes longer to manifest. One month to 45 days (choice B) is also shorter than the average incubation period for hepatitis B. Up to 6 months (choice D) is too long for hepatitis B, as the virus typically shows symptoms within 3 months.
The sepsis is:
- A. Presence of bacteria in the blood
- B. Bacteremia, accompanied with chemical and laboratory data for systemic information
- C. Massive proliferation of toxins in the blood with organ failure
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D. Sepsis is a systemic response to infection resulting in organ dysfunction.
A: Sepsis can be caused by bacterial infection, but it is not solely defined by the presence of bacteria in the blood.
B: Bacteremia is the presence of bacteria in the blood, which can be a component of sepsis, but sepsis involves a broader systemic response beyond just bacteremia.
C: Sepsis can lead to the release of toxins and organ failure, but sepsis itself is not defined solely by the massive proliferation of toxins.
Therefore, the correct answer is D, as sepsis can involve the presence of bacteria, bacteremia, systemic manifestations, and organ failure.
Which bacteria is responsible for causing pneumonia?
- A. Streptococcus pneumoniae
- B. Mycobacterium tuberculosis
- C. Escherichia coli
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D: All of the above. Streptococcus pneumoniae, Mycobacterium tuberculosis, and Escherichia coli can all cause pneumonia, but through different mechanisms. S. pneumoniae is a common cause of community-acquired pneumonia, M. tuberculosis can lead to tuberculosis-related pneumonia, and E. coli can cause pneumonia in immunocompromised individuals. Therefore, all three bacteria can be responsible for causing pneumonia, making option D the correct choice. Option A, Streptococcus pneumoniae, is correct but does not cover all possible causes of pneumonia. Option B, Mycobacterium tuberculosis, is too specific and does not include other common causes. Option C, Escherichia coli, is also a possible cause of pneumonia but does not account for all potential pathogens.