Nokea
A patient with diarrhea had stool microscopy revealing flagellated protozoa with two nuclei. What is the most likely causative agent?
- A. Giardia lamblia
- B. Entamoeba histolytica
- C. Trichomonas vaginalis
- D. Balantidium coli
Correct Answer: A
Rationale: The correct answer is A: Giardia lamblia. Giardia lamblia is a flagellated protozoan with two nuclei, known as the "falling leaf" appearance. It causes diarrhea in humans through ingestion of contaminated water or food. Entamoeba histolytica causes amoebic dysentery, characterized by bloody diarrhea and colitis. Trichomonas vaginalis is a sexually transmitted protozoan causing vaginal discharge but is not found in stool. Balantidium coli is a ciliated protozoan causing diarrhea but does not have flagellated forms.
You may also like to solve these questions
A smear prepared from material obtained from patient with suspected diphtheria contains yellow bacilli with blue grains at their ends. What staining was used in this case?
- A. Ziehl-Nielsen
- B. Kozlovsky
- C. Romanovsky
- D. Loefler
Correct Answer: D
Rationale: The correct answer is D: Loefler. This staining method is used for identifying Corynebacterium diphtheriae, the causative agent of diphtheria. It involves using methylene blue and basic fuchsin to stain the bacteria. The yellow bacilli with blue grains at their ends indicate the characteristic appearance of C. diphtheriae when stained using the Loefler method.
Choice A: Ziehl-Nielsen is used for acid-fast bacteria like Mycobacterium tuberculosis.
Choice B: Kozlovsky is not a standard staining method in microbiology.
Choice C: Romanovsky is used for blood smears to identify malaria parasites.
A patient with a sore throat had a throat smear revealing Gram-positive cocci in pairs with a capsule. What is the most likely causative agent?
- A. Streptococcus pneumoniae
- B. Neisseria meningitidis
- C. Haemophilus influenzae
- D. Klebsiella pneumoniae
Correct Answer: A
Rationale: Rationale:
1. Gram-positive cocci in pairs indicate Streptococcus pneumoniae.
2. Presence of a capsule points to S. pneumoniae as it has a polysaccharide capsule.
3. S. pneumoniae commonly causes sore throat.
4. Neisseria meningitidis, Haemophilus influenzae, and Klebsiella pneumoniae are not typically associated with sore throat.
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 of the following bacteria is responsible for causing the disease known as syphilis?
- A. Treponema pallidum
- B. Neisseria gonorrhoeae
- C. Chlamydia trachomatis
- D. Escherichia coli
Correct Answer: A
Rationale: The correct answer is A: Treponema pallidum. This bacterium is responsible for causing syphilis due to its unique spiral shape and ability to penetrate mucous membranes. It is transmitted through sexual contact or from mother to child during childbirth. Neisseria gonorrhoeae causes gonorrhea, Chlamydia trachomatis causes chlamydia, and Escherichia coli is a common bacterium found in the gut. Therefore, they are not responsible for syphilis.
A smear of sputum from the patient with suspected lobar pneumonia was stained with the use of the following stains and reagents: solution of gentian violet, Lugol’s solution, 960 alcohol, watermagenta. What staining method was applied in this case?
- A. Gram
- B. Ziehl-Nielsen's
- C. Romanovsky
- D. Neisser
Correct Answer: A
Rationale: The correct answer is A: Gram staining method. The rationale is as follows:
1. Gentian violet is a primary stain used in the Gram staining procedure to stain the bacterial cells.
2. Lugol's solution is a mordant that helps to fix the crystal violet stain in Gram-positive bacteria.
3. 95% alcohol is used as a decolorizing agent in the Gram staining process to remove the stain from Gram-negative bacteria.
4. Watermagenta is not a standard reagent in the Gram staining method.
Therefore, based on the reagents mentioned, the staining method applied in this case is the Gram staining method.
Other choices are incorrect:
B: Ziehl-Nielsen's - This staining method is used for acid-fast staining, not for lobar pneumonia.
C: Romanovsky - This staining method is used for blood smears, not for bacterial staining in pneumonia.
D: Neisser - This staining method is not commonly used in routine bacterial staining procedures.