A man is suffering from diarrhea. In summer he spent his vacation in the south at the sea coast. Bacteria with the following properties were detected in his feces: gram-negative curved mobile monotrichous bacilli that do not produce spores or capsules. They are undemanding to nutrient medium but require alkaline reaction (Ñ€H 8.5-9.5). Described are the agents of the following enteric infection:

Correct Answer: A

Rationale: Step-by-step rationale for why the correct answer is A (Cholera): 1. Gram-negative curved mobile monotrichous bacilli: Vibrio cholerae, the causative agent of cholera, fits this description. 2. Do not produce spores or capsules: Vibrio cholerae does not produce spores or capsules. 3. Require alkaline reaction (pH 8.5-9.5): Vibrio cholerae thrives in alkaline environments. 4. Enteric infection: Cholera is a classic example of an enteric infection transmitted through contaminated food or water. Summary of why other choices are incorrect: B: Shigellosis is caused by Shigella species, which are gram-negative, but they are not curved bacilli and do not require an alkaline pH. C: Typhoid fever is caused by Salmonella Typhi, which are gram-negative but are not curved bacilli and do not require an alkaline pH.

Correct Answer: D

Rationale: The correct answer is D because utilizing all three methods—immunofluorescence, viral neutralization reaction, and electron microscopy—provides a comprehensive and rapid diagnosis of various viral infections. Immunofluorescence detects viral antigens directly, viral neutralization reaction demonstrates the presence of specific antibodies, and electron microscopy visualizes viral particles. This combination ensures accurate and quick identification of different viruses. Choices A, B, and C alone may not cover all aspects of viral diagnosis, making them less effective compared to the comprehensive approach of using all three methods.

Correct Answer: B

Rationale: The correct answer is B: serratia spp. This is because serratia spp. are not typically found in the normal skin microflora. Normal skin microflora primarily consist of bacteria such as diphtheroids, alpha-hemolytic streptococci, and epidermidis. Serratia spp. are more commonly associated with healthcare-associated infections rather than being a part of the skin's natural bacterial flora. Therefore, choice B is the correct answer. Choices A, C, and D are incorrect as they are commonly found in the normal skin microflora.

Correct Answer: A

Rationale: The correct answer is A: anabolic. Anabolic reactions involve the synthesis of larger organic molecules from smaller precursor molecules. This process requires energy input and is essential for growth and repair in living organisms. Choice B: Catabolic reactions involve the breakdown of larger molecules into smaller ones, releasing energy in the process. This is the opposite of what is described in the question. Choice C: Metabolic is a broad term that encompasses all chemical processes in living organisms, including both anabolic and catabolic reactions. It is not specific to the assembly of small molecules into larger ones. Choice D: "Any of the above" is incorrect because only anabolic reactions specifically involve the assembly of small precursor molecules into larger organic molecules.

Correct Answer: A

Rationale: The correct answer is A: Sandfly. Cutaneous leishmaniasis is transmitted by the bite of infected sandflies. These tiny insects are known vectors for Leishmania parasites. Sandflies are active during dusk and night, feeding on blood from mammals, including humans. Tick (B), mosquito (C), and tsetse fly (D) are not vectors for Leishmania parasites. Ticks transmit diseases like Lyme disease, mosquitoes transmit diseases like malaria, and tsetse flies transmit African trypanosomiasis. Therefore, the correct vector for cutaneous leishmaniasis is the sandfly due to its specific role in transmitting the Leishmania parasite.