Resident microflora is found in

Correct Answer: C

Rationale: The correct answer is C: urethra. Resident microflora refers to the normal, beneficial bacteria that inhabit a specific area of the body without causing harm. The urethra is one of the locations where resident microflora are commonly found. These bacteria play a vital role in maintaining a healthy balance and preventing harmful pathogens from colonizing the urethra. Blood (A), lung (B), and cerebro-spinal fluid (D) are not typical locations for resident microflora as these areas are usually sterile or have very limited microbial presence to prevent infections.

Correct Answer: B

Rationale: Answer B, Infectious mononucleosis, is not caused by enteroviruses. Infectious mononucleosis is primarily caused by the Epstein-Barr virus, a member of the herpesvirus family, not by enteroviruses. Enteroviruses are known to cause diseases such as myocarditis, herpangina, and Boston exanthema. Therefore, B is the correct answer. Myocarditis, herpangina, and Boston exanthema can all be caused by enteroviruses, making choices A, C, and D incorrect, respectively.

Correct Answer: D

Rationale: The correct answer is D because the defense role of the skin is not related to lysozyme activity. Lysozyme is an enzyme found in tears, saliva, and mucus, not specifically in the skin. The skin's defense role is primarily related to its physical barrier function, low pH creating an acidic environment that inhibits microbial growth, secretion of antimicrobial peptides, and the activity of skin macrophages that phagocytose pathogens. Choices A, B, and C are true statements as they correctly describe different aspects of the skin's defense mechanisms.

Correct Answer: B

Rationale: The correct answer is B because reinfection is indeed possible with rabies virus. Step 1: Reinfection occurs if a person is exposed to the virus again after initial infection. Step 2: Once infected, the virus can remain dormant in the body and become active upon re-exposure. Step 3: Therefore, it is essential to continue preventive measures even after initial immunization. Summary: Choices A, C, and D are incorrect because antibodies develop within 14-15 days post-immunization, HRIG is administered shortly after exposure, and a specific vaccination schedule is followed for rabies prophylaxis, respectively.

Correct Answer: B

Rationale: The correct answer is B: Vibrio cholerae. Vibrio cholerae is a comma-shaped rod bacterium that causes high volume watery diarrhea by producing cholera toxin. This toxin leads to the secretion of large amounts of fluid into the intestines. Campylobacter jejuni (A) typically causes bloody diarrhea. Pseudomonas aeruginosa (C) and Proteus mirabilis (D) are not associated with high volume watery diarrhea.