When examining a patient presumptively diagnosed with food toxicoinfection, a doctor on duty has detected symptoms characteristic of botulism. The patient named the meals he ate the day before. What is the most probable cause of infection?

Correct Answer: A

Rationale: The correct answer is A: Homemade canned meat. Botulism is caused by the Clostridium botulinum bacteria, which thrives in low-oxygen environments like improperly canned food. Homemade canned meat poses a higher risk of contamination as it may not have been processed correctly, allowing the bacteria to grow and produce toxins. Custard pastry, sour cream, and strawberries are less likely to cause botulism as they are not typically associated with the bacteria unless improperly handled or stored. Homemade canned meat is the most probable cause based on the characteristic symptoms of botulism and the conditions that favor the growth of Clostridium botulinum in canned food.

Correct Answer: D

Rationale: The correct answer is D because all three bacteria (Clostridium botulinum, Salmonella enterica, Escherich:ia coli) are known to produce toxins causing foodborne illnesses. Clostridium botulinum produces botulinum toxin, causing botulism. Salmonella enterica produces toxins leading to salmonellosis. Escherichia coli can produce toxins like Shiga toxin causing food poisoning. Choices A, B, and C are incorrect because each bacterium is individually known to produce toxins causing foodborne illnesses, thus the correct answer is D.

Correct Answer: B

Rationale: The correct answer is B: Movement of the bacterial cell. Bacterial flagella are whip-like appendages that enable bacteria to move towards nutrients or away from harmful substances. This movement is essential for survival, dispersal, and colonization. Choice A is incorrect because attachment is primarily mediated by other structures like pili. Choice C is incorrect as protein synthesis occurs inside the cell and is not directly related to flagella. Choice D is incorrect as nutrient absorption is typically carried out through specific channels or transport systems, not by flagella.

Correct Answer: A

Rationale: Rationale for Correct Answer (A: Fluconazole): Fluconazole is an antifungal medication used to treat yeast infections caused by Candida albicans. It targets the fungal cell membrane, disrupting its structure and function. This makes it an effective treatment for oral thrush, which is caused by Candida overgrowth in the oral mucosa. The continuous use of antibiotics can disrupt the normal balance of microorganisms in the body, leading to fungal overgrowth. Fluconazole specifically targets the yeast fungi without affecting bacteria, making it the appropriate choice for this complication. Summary of Incorrect Choices: B: Biseptol - Biseptol is an antibiotic that targets bacteria, not fungi like Candida albicans. C: Tetracycline - Tetracycline is also an antibiotic that targets bacteria, not fungi. D: Furazolidone - Furazolidone is an antibiotic primarily used for treating bacterial infections, not fungal infections like oral thrush caused by Candida

Correct Answer: A

Rationale: The correct answer is A: Late congenital syphilis. The symptoms described align with late congenital syphilis, which includes saddle nose, high-arched palate, natiform skull, peg-shaped incisors, and notched cutting edge. Lymph nodes not being affected is also consistent with late congenital syphilis. Early congenital syphilis (B) typically presents with more severe symptoms at birth or shortly after. Tertiary syphilis (C) usually occurs years after initial infection and presents with different symptoms. Fluorosis (D) is caused by excessive fluoride intake and does not match the symptoms described.

Correct Answer: A

Rationale: The correct answer is A: Pseudomonas aeruginosa. Pseudomonas aeruginosa is known for producing a blue-green pigment called pyocyanin, which gives the characteristic color seen in the wound abscess. The distinctive odor of jasmine is also a key feature of Pseudomonas aeruginosa. Proteus vulgaris (B) and Klebsiella pneumoniae (D) do not produce blue-green pigment or have a jasmine-like odor. Escherichia coli (C) typically does not produce blue-green pigment or have a jasmine-like odor.

Correct Answer: B

Rationale: The correct answer is B because viruses can indeed be cultured on hen embryos, cell cultures, and experimental animals in vitro. This method allows for the replication and study of viruses outside the host organism. Option A is incorrect as viral cultivation is possible in laboratory settings. Option C is incorrect because while viruses can be grown on nutrient media, it is not the only method. Option D is incorrect as viruses can be cultured in various types of cell cultures, not just human embryonic ones.

Correct Answer: B

Rationale: The correct answer is B: Fimbriae. Fimbriae are hair-like appendages found on the surface of bacteria that enable attachment to host cells. This attachment is crucial for establishing infection. Flagella (A) are used for movement, not attachment. Capsules (C) provide protection and help evade the host immune system, but do not directly facilitate attachment. Endospores (D) are dormant structures for survival, not for attachment to host cells. Fimbriae specifically aid in adherence to host cells, making them the correct choice in this context.

Correct Answer: A

Rationale: The correct answer is A: Vibrio cholerae. This bacterium produces the cholera toxin, an enterotoxin that causes profuse watery diarrhea by disrupting the normal function of the intestines. Vibrio cholerae is specifically known for causing cholera, a severe diarrheal disease. Clostridium botulinum (B) produces botulinum toxin, causing botulism (paralysis, not diarrhea). Escherichia coli (C) can produce enterotoxins, but the question specifies a specific enterotoxin causing diarrhea, which is not a characteristic of all strains of E. coli. Streptococcus pneumoniae (D) is a common cause of respiratory infections but does not produce an enterotoxin causing diarrhea.