Nokea
Specimen of a patient's sputum was stained with the following dyes and reagents: Ziehl's solution, methylene blue solution, 5% solutoin of sulfuric acid. What staining method was applied?
- A. Ziehl-Neelsen
- B. Burri's
- C. Gram's
- D. Peshkov's
Correct Answer: A
Rationale: The correct answer is A: Ziehl-Neelsen staining method was applied.
1. Ziehl's solution is used as a primary stain in Ziehl-Neelsen staining for acid-fast organisms like Mycobacterium tuberculosis.
2. Sulfuric acid is used as a decolorizer to remove excess stain.
3. Methylene blue is not part of the Ziehl-Neelsen staining method.
4. Burri's, Gram's, and Peshkov's staining methods are not used for acid-fast staining.
You may also like to solve these questions
Microscopic examination of a patient's duodenal contents revealed protozoa with two nuclei, four flagella, and a ventral adhesive disc. What is the likely causative agent?
- A. Giardia lamblia
- B. Leishmania donovani
- C. Entamoeba coli
- D. Trypanosoma gambiense
Correct Answer: A
Rationale: The correct answer is A: Giardia lamblia. This protozoan matches the description of the causative agent because it has two nuclei, four flagella, and a ventral adhesive disc. Giardia lamblia is commonly found in the duodenum and causes giardiasis. The other choices can be eliminated because Leishmania donovani causes visceral leishmaniasis, not the described symptoms. Entamoeba coli is a non-pathogenic amoeba found in the large intestine. Trypanosoma gambiense causes African trypanosomiasis and is transmitted by the tsetse fly, not matching the described characteristics.
The causative agent of the pertussis (also known as whooping cough) morphologically appears as:
- A. Gram positive bacillus
- B. Gram negative coccobacillus
- C. Long Gram-negative rod shaped bacterium
- D. None of the above
Correct Answer: B
Rationale: The correct answer is B: Gram negative coccobacillus. Bordetella pertussis, the causative agent of pertussis, is a gram-negative coccobacillus. This is because it is a small, rod-shaped bacterium that appears both as a bacillus (rod-shaped) and a coccus (spherical) shape. It does not retain the crystal violet stain in the Gram staining process, indicating its negative gram nature. Choice A is incorrect because pertussis is not a gram-positive bacillus. Choice C is incorrect because pertussis is not a long gram-negative rod-shaped bacterium. Choice D is incorrect as the other options do not accurately describe the morphology of Bordetella pertussis.
Which statement is correct? Yersinia pestis is the causative agent of:
- A. Cholera
- B. AIDS
- C. Plague
- D. None of the above
Correct Answer: C
Rationale: The correct answer is C: Plague. Yersinia pestis is a bacterium that causes plague, a serious infectious disease transmitted through infected fleas or direct contact with infected animals. Yersinia pestis does not cause Cholera (choice A) or AIDS (choice B). Choice D, None of the above, is incorrect as Yersinia pestis is indeed the causative agent of plague.
During examination of the patient's oral cavity a dentist noticed deformation of the teeth and a crescent indentation of the upper right incisor. The teeth are undersized, barrel-shaped – tooth cervix is wider than its edge. The patient uses a hearing aid, suffers from visual impairment. What type of syphilis affects teeth in such way?
- A. Primary
- B. Early congenital
- C. Neurosyphilis
- D. Late congenital
Correct Answer: D
Rationale: The correct answer is D, Late congenital syphilis. This is because the patient presents with Hutchinson's teeth, which are a characteristic feature of late congenital syphilis. Hutchinson's teeth are small, barrel-shaped teeth with a wider cervix and notched incisors. The patient's history of visual impairment and hearing aid use also support the diagnosis of late congenital syphilis, as these are common manifestations of this stage of the disease.
Choice A, Primary syphilis, is incorrect because it typically presents with a painless sore at the site of infection, not dental abnormalities. Choice B, Early congenital syphilis, is incorrect as dental abnormalities in this stage are usually more severe, such as mulberry molars. Choice C, Neurosyphilis, is incorrect as it primarily affects the central nervous system and does not typically present with dental abnormalities.
Infectious disease' is:
- A. Clinical term
- B. A term expressing the possibility of developing certain symptoms in an infection
- C. A+B
- D. No correct answer
Correct Answer: C
Rationale: The correct answer is C because "Infectious disease" is a combination of both a clinical term (A) and a term expressing the possibility of developing certain symptoms in an infection (B). Infectious diseases are illnesses caused by pathogenic microorganisms, such as bacteria, viruses, parasites, or fungi, that can spread directly or indirectly from person to person. Therefore, the term encompasses both the clinical aspect of the disease and the potential symptoms that may manifest in an infected individual. Choices A and B alone do not fully capture the comprehensive definition of infectious disease, making C the correct answer. Choice D is incorrect as there is a correct answer in this case.