Nokea
Microscopic examination of vaginal discharge revealed pear-shaped flagellated protozoa with an undulating membrane. What is the causative agent?
- A. Trichomonas vaginalis
- B. Giardia lamblia
- C. Trypanosoma brucei
- D. Leishmania donovani
Correct Answer: A
Rationale: The correct answer is A: Trichomonas vaginalis. Trichomonas vaginalis is a sexually transmitted protozoan that causes trichomoniasis. The pear-shaped flagellated protozoa with an undulating membrane described in the question match the morphology of Trichomonas vaginalis. It is typically found in vaginal discharge of infected individuals. Giardia lamblia (B) is a different protozoan that causes giardiasis and has a distinct morphology of a teardrop shape with flagella. Trypanosoma brucei (C) causes African sleeping sickness and Leishmania donovani (D) causes visceral leishmaniasis, both of which have different morphologies and clinical presentations compared to Trichomonas vaginalis.
You may also like to solve these questions
Which 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 fetus. Neisseria gonorrhoeae causes gonorrhea, Chlamydia trachomatis causes chlamydia, and Escherichia coli is a common bacterium in the gastrointestinal tract. Syphilis is distinct due to its characteristic symptoms and stages, making Treponema pallidum the correct choice.
A man is being treated for chronic pneumonia for a long time. Microscopy of sputum smears stained using Ziehl-Nielsen method reveals red bacilli 0.25x4 microns in size, located separately or sometimes in small clusters. What disease can be suspected?
- A. Pneumococcal pneumonia
- B. Pulmonary actinomycosis
- C. Pulmonary candidiasis
- D. Pulmonary tuberculosis
Correct Answer: D
Rationale: The correct answer is D: Pulmonary tuberculosis. The presence of red bacilli stained with Ziehl-Nielsen method indicates acid-fast bacteria, which are characteristic of Mycobacterium tuberculosis, the causative agent of tuberculosis. The size and appearance of the bacilli described match those of M. tuberculosis. Chronic pneumonia, along with the specific staining pattern, strongly suggests tuberculosis as the likely diagnosis.
Explanation for other choices:
A: Pneumococcal pneumonia is caused by Streptococcus pneumoniae, which would not show red bacilli on Ziehl-Nielsen staining.
B: Pulmonary actinomycosis is caused by Actinomyces species, not acid-fast bacteria like M. tuberculosis.
C: Pulmonary candidiasis is caused by Candida species, which are fungi and do not appear as red bacilli on staining.
Which IS NOT true about sexually transmitted infections?
- A. Some sexually transmitted infections are endemic for some regions
- B. They are a significant healthy, social and economic problem
- C. Only infections that are transmitted solely by sexual contact are included
- D. They are anthroponotic diseases
Correct Answer: C
Rationale: Step 1: Define sexually transmitted infections (STIs) as infections primarily spread through sexual contact.
Step 2: Understand that STIs can also be transmitted through non-sexual means like blood transfusions.
Step 3: Recognize that choice C is incorrect as it limits STIs to only sexually transmitted infections.
Step 4: Therefore, the correct answer is C as it does not encompass all possible modes of transmission for STIs.
Summary: Choices A, B, and D are incorrect as they all accurately describe the characteristics of sexually transmitted infections, while choice C is incorrect as it excludes other potential modes of transmission for STIs.
Bacteria that can cause tuberculosis in humans are:
- A. Mycobacterium bovis
- B. Mycobacterium tuberculosis
- C. All answers are correct
- D. None of the above
Correct Answer: C
Rationale: The correct answer is C because both Mycobacterium bovis and Mycobacterium tuberculosis are bacteria that can cause tuberculosis in humans. Mycobacterium bovis primarily infects animals but can be transmitted to humans, while Mycobacterium tuberculosis is the main causative agent of tuberculosis in humans. Therefore, both choices A and B are correct. Choice D is incorrect because we know that Mycobacterium bovis and Mycobacterium tuberculosis are causative agents of tuberculosis in humans.
Which of the following statements is NOT TRUE about the fungi?
- A. They reproduce sexually and asexually
- B. They have a cell wall
- C. They are aerobes or facultative anaerobes
- D. They form flagella
Correct Answer: D
Rationale: The correct answer is D because fungi do not form flagella. Fungi reproduce sexually and asexually (A) through spores, have a cell wall (B) made of chitin, and are mostly aerobic or facultative anaerobes (C). Flagella are structures found in some protozoa and bacteria, not in fungi. Therefore, option D is the only statement that is not true about fungi.