Which of the following statements is true regarding polio vaccines:

Correct Answer: A

Rationale: The correct answer is A: Salk and Sabin vaccines are vaccines against polio. Both Salk and Sabin vaccines are indeed vaccines specifically developed to prevent polio. The Salk vaccine is an inactivated polio vaccine, while the Sabin vaccine is an oral live attenuated vaccine. Therefore, choice B is incorrect as the Sabin vaccine is live attenuated, not inactivated. Choice C is also incorrect because the Salk vaccine is inactivated, not live attenuated. Choice D is incorrect because not all statements are true; only statement A is accurate.

Correct Answer: A

Rationale: Rationale: 1. Endo agar inhibits the growth of Gram-positive bacteria. 2. Colorless colonies on Endo agar indicate lactose non-fermenting bacteria. 3. Shigella dysenteriae is a lactose non-fermenting, Gram-negative rod, causing dysentery. 4. Salmonella typhi, Escherichia coli, and Proteus vulgaris are lactose fermenters, so they would produce pink colonies on Endo agar. Therefore, the most likely causative agent is Shigella dysenteriae.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: D

Rationale: The correct answer is D: Paramyxoviridae. Mumps virus is a member of the Paramyxoviridae family, based on its characteristics such as structure, genome organization, and replication cycle. Paramyxoviruses are enveloped, non-segmented RNA viruses with a helical nucleocapsid. They replicate in the cytoplasm and bud from the host cell membrane. Coronaviridae (A) are a different family of viruses with distinct characteristics. Picornaviridae (B) and Orthomyxoviridae (C) are also different families with unique features that do not match those of the mumps virus.

Correct Answer: A

Rationale: The correct answer is A: Syphilis. Hutchinson's triad is a classic presentation of congenital syphilis. Barrel-shaped teeth, parenchymatous keratitis, and deafness are hallmark signs. These occur due to infection of the fetus by the spirochete Treponema pallidum. Syphilis can lead to various systemic manifestations, including skeletal abnormalities, skin lesions, and neurological complications. Opisthorchiasis, Toxoplasmosis, and Tuberculosis do not typically present with the specific triad described in the question. Opisthorchiasis is a parasitic infection, Toxoplasmosis is caused by a protozoan, and Tuberculosis is a bacterial infection that primarily affects the lungs.

Correct Answer: C

Rationale: Step-by-step rationale for why choice C (Adenoviridae) is correct: 1. Adenoviruses commonly cause respiratory illnesses such as the common cold and bronchitis. 2. They are highly contagious and easily spread through respiratory secretions. 3. Adenoviruses are a common cause of viral conjunctivitis as well. 4. Other choices are incorrect because herpesviruses (choice A) typically cause different types of infections, papovaviruses (choice B) are not common respiratory pathogens, and poxviruses (choice D) are not typically associated with respiratory illnesses.

Correct Answer: A

Rationale: The correct answer is A: BCG vaccine. Step 1: BCG vaccine is specifically designed to protect against tuberculosis, making it the appropriate choice for newborns. Step 2: STI vaccine is for sexually transmitted infections, not tuberculosis. Step 3: EV vaccine is not a recognized vaccine. Step 4: DPT vaccine protects against diphtheria, pertussis, and tetanus, not tuberculosis. In summary, BCG vaccine is the correct choice as it targets tuberculosis specifically, while the other options are designed for different purposes.

Correct Answer: B

Rationale: The correct answer is B: Tuberculosis and mycobacterioses. Mycobacterium tuberculosis, the causative agent of tuberculosis, and other mycobacteria can survive in the soil for extended periods. Here's the rationale: 1. Mycobacteria have a waxy cell wall that provides resistance to harsh environmental conditions. 2. The slow growth rate of mycobacteria allows them to persist in the soil for long periods. 3. Tuberculosis and mycobacterioses are known to be transmitted through environmental exposure, including soil. 4. Colibacillosis and cholera (Choice C) are caused by enteric bacteria that do not survive well in soil. 5. Leptospirosis and plague (Choice D) are bacterial diseases transmitted through animal hosts and are not known to be soil-borne.

Correct Answer: A

Rationale: The correct answer is A: spleen. The spleen is not a component of the gastrointestinal tract; it is part of the lymphatic system. The pharynx, esophagus, and stomach are all part of the gastrointestinal tract responsible for digestion and absorption of food. The spleen's main functions include filtering blood, storing blood cells, and supporting the immune system, making it unrelated to the digestive process.