During the staining of sputum smear of a patient with suspected croupous pneumonia the following reactives and stainers were used: gentian violet solution, Lugol's solution, 960 spiritus and water fuchsin. What method of staining is used in this case?

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Question 1 of 9

During the staining of sputum smear of a patient with suspected croupous pneumonia the following reactives and stainers were used: gentian violet solution, Lugol's solution, 960 spiritus and water fuchsin. What method of staining is used in this case?

Correct Answer: B

Rationale: The correct answer is B: Gram's staining method. The rationale for this is as follows: Gentian violet and Lugol's solution are used as primary and mordant stains in the Gram's staining method. Spiritus 960 is used as a decolorizer, and water fuchsin is used as a counterstain. This staining method is commonly used in microbiology to differentiate bacteria into Gram-positive and Gram-negative based on their cell wall characteristics. A: Leffler's staining method is used for the identification of diphtheria bacilli. C: Ziehl-Neelsen's staining method is used for acid-fast bacteria like Mycobacterium tuberculosis. D: Neisser's staining method is used for the identification of Neisseria species. In summary, the use of specific reactives and stainers in the question indicates the application of the Gram's staining method for bacterial differentiation.

Question 2 of 9

During the staining of sputum smear of a patient with suspected croupous pneumonia the following reactives and stainers were used: gentian violet solution, Lugol's solution, 960 spiritus and water fuchsin. What method of staining is used in this case?

Correct Answer: B

Rationale: The correct answer is B: Gram's staining method. The rationale for this is as follows: Gentian violet and Lugol's solution are used as primary and mordant stains in the Gram's staining method. Spiritus 960 is used as a decolorizer, and water fuchsin is used as a counterstain. This staining method is commonly used in microbiology to differentiate bacteria into Gram-positive and Gram-negative based on their cell wall characteristics. A: Leffler's staining method is used for the identification of diphtheria bacilli. C: Ziehl-Neelsen's staining method is used for acid-fast bacteria like Mycobacterium tuberculosis. D: Neisser's staining method is used for the identification of Neisseria species. In summary, the use of specific reactives and stainers in the question indicates the application of the Gram's staining method for bacterial differentiation.

Question 3 of 9

Cholera is a serious gastrointestinal illness caused by bacteria of the genus:

Correct Answer: C

Rationale: The correct answer is C: Vibrio. Cholera is caused by Vibrio cholerae bacteria. These bacteria produce a toxin that causes severe diarrhea and dehydration. Escherichia (choice A) and Salmonella (choice B) are known for causing other types of gastrointestinal infections but not cholera. Acinetobacter (choice D) typically causes respiratory infections, not gastrointestinal illnesses like cholera. Therefore, the correct choice is Vibrio as it is specifically associated with cholera.

Question 4 of 9

Microscopic analysis of tissue sampling from affected area of mucous membrane of oral cavity revealed bacillus in form of accumulations that looked like a pack of cigarettes. Ziehl-Neelsen staining gives them red colour. What kind of pathogenic organism was most likely revealed in tissue sampling?

Correct Answer: B

Rationale: The correct answer is B: M.tuberculosis. The description of bacillus in the form of accumulations resembling a pack of cigarettes and staining red with Ziehl-Neelsen staining is characteristic of Mycobacterium tuberculosis. M.leprae (Choice A) is associated with leprosy and does not typically appear as described. A.bovis (Choice C) is a type of Mycobacterium but is not typically found in the oral cavity. A.israilii (Choice D) is not associated with the characteristics mentioned in the question. Therefore, based on the specific characteristics described, M.tuberculosis is the most likely pathogenic organism revealed in the tissue sampling.

Question 5 of 9

Which of the following bacteria is known for producing a capsule that helps it avoid the immune system?

Correct Answer: A

Rationale: The correct answer is A: Streptococcus pneumoniae. This bacterium is known for producing a capsule that helps it evade the immune system. The capsule acts as a protective barrier, making it difficult for the immune system to recognize and attack the bacteria. Streptococcus pneumoniae is a common cause of pneumonia and meningitis. Explanation for why other choices are incorrect: B: Escherichia coli does not typically produce a capsule for immune evasion. It is more commonly associated with gastrointestinal infections. C: Salmonella enterica also does not produce a capsule for immune evasion. It is known for causing foodborne illness. D: Bacillus subtilis is a soil bacterium that is not known for producing a capsule to avoid the immune system.

Question 6 of 9

A 49-year-old countryman got an itching papule on the dorsum of his right hand. In the centre there is a vesicle with serosanginous exudate. Within the next 2 days the patient developed a painless edema of hand and forearm. On the 4th day the temperature rose to 38,5oC, in the right axillary region a large painful lymph node was found. One daybefore the onset of the disease the patient had examined a dead calf. What is the most likely diagnosis?

Correct Answer: D

Rationale: The most likely diagnosis is D: Lymphocutaneous tularemia. The key clues include exposure to a dead animal, vesicle with serosanginous exudate, painless edema progressing to lymph node involvement, and fever. Tularemia is caused by Francisella tularensis, commonly acquired through contact with infected animals. The characteristic ulcer at the site of entry, lymphadenopathy, and systemic symptoms point towards tularemia. Cutaneous anthrax (A) presents with a painless ulcer and black eschar. Bubonic plague (B) typically presents with buboes (swollen lymph nodes) and fever. Carbuncle (C) is a deep skin infection typically caused by Staphylococcus aureus.

Question 7 of 9

What are actinomycotic granules:

Correct Answer: C

Rationale: Step 1: Actinomycotic granules are colonies of actinomycetes located in purulent secretions. Step 2: Actinomycosis is a disease caused by actinomycetes forming these granules. Step 3: Actinomycotic granules are typically found in tissue exudates or pus. Step 4: Therefore, choice C is correct as it accurately describes actinomycotic granules. Summary: Choice A is incorrect because actinomycotic granules are not a form of actinomycosis itself, but a characteristic of the disease. Choice B is incorrect as actinomycotic granules are not an additional outer membrane but rather colonies of actinomycetes. Choice D is incorrect as actinomycotic granules are not intracellular inclusions but extracellular colonies found in purulent secretions.

Question 8 of 9

A wound infection culture grew Gram-positive cocci in clusters. The bacteria were catalase-positive and coagulase-negative. What is the likely microorganism?

Correct Answer: A

Rationale: The correct answer is A: Staphylococcus epidermidis. The presence of Gram-positive cocci in clusters, along with being catalase-positive and coagulase-negative, is indicative of Staphylococcus species. Staphylococcus epidermidis is commonly found on the skin, making it likely to cause wound infections. Summary: B: Staphylococcus aureus is catalase-positive and coagulase-positive. C: Streptococcus pyogenes is catalase-negative. D: Enterococcus faecalis is catalase-negative.

Question 9 of 9

A patient with convulsive contractions of facial muscles was admitted to the infectious disease ward. From a scratch on his lower right extremity analysts isolated bacteria with terminal endospores that gave them drumstick appearance. What bacteria are compliant with given description?

Correct Answer: A

Rationale: Step-by-step rationale for the correct answer (A - Clostridium tetani): 1. The patient has convulsive contractions of facial muscles, indicating tetanus. 2. Isolation of bacteria with terminal endospores that have a drumstick appearance is characteristic of Clostridium tetani. 3. Clostridium tetani produces tetanospasmin toxin causing muscle spasms. 4. Therefore, the correct answer is Clostridium tetani (A). Summary of why other choices are incorrect: B: Clostridium botulinum causes botulism, not tetanus. C: Clostridium perfringens causes gas gangrene, not tetanus. D: Bacillus anthracis causes anthrax, not tetanus.

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