In a maternity hospital a newborn should receive vaccination against tuberculosis. What vaccine should be chosen?

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: C

Rationale: Rationale: 1. Candida is a fungus commonly isolated from clinical specimens. 2. Sabouraud agar is the most suitable medium for Candida due to its low pH and high dextrose content. 3. Low pH inhibits bacterial growth, while dextrose promotes fungal growth. 4. Zeisler media, Chocolate agar, and Muller-Hinton agar are not specific for fungal isolation. Summary: - Zeisler media is used for anaerobic bacteria. - Chocolate agar is used for fastidious organisms like Haemophilus. - Muller-Hinton agar is for antibiotic susceptibility testing, not fungal isolation.

Correct Answer: B

Rationale: The correct answer is B: CDC. The Centers for Disease Control and Prevention (CDC) is responsible for establishing hand-washing guidelines in healthcare settings to prevent infections. CDC is a leading authority in public health and provides evidence-based recommendations. OSHA (A) focuses on workplace safety, NIAD (C) is not a recognized organization, and WHO (D) provides global health guidelines but CDC is the primary authority for hand hygiene in the US healthcare system.

Correct Answer: B

Rationale: Gas gangrene is caused by Clostridium perfringens due to its ability to produce gas in tissues leading to necrosis. Other choices are incorrect: A (C. difficile causes diarrhea), C (C. tetani causes tetanus), and D (incorrect as B is the causative agent).

Correct Answer: D

Rationale: The correct answer is D because virulent strains of Listeria monocytogenes exhibit multiple pathogenic factors. A: They do not have endotoxin-like substances, so this is incorrect. B: They are indeed facultative intracellular bacteria, aiding in their ability to survive and replicate inside host cells. C: They produce hemolysin, which helps them lyse red blood cells. Therefore, the correct answer is D, as all of the above statements are true for virulent strains of Listeria monocytogenes.

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.

Correct Answer: A

Rationale: The correct answer is A: Metronidazole. Amebic dysentery is caused by the parasite Entamoeba histolytica, not a bacterium, hence antibiotics like Chloramphenicol or Phthalazole are ineffective. Metronidazole is the drug of choice for treating amebic dysentery due to its efficacy against anaerobic organisms like Entamoeba histolytica. Furasolidone is used for treating bacterial infections, not parasitic ones like amebiasis. The patient's symptoms of diarrhea, stomach aches, and a recent history of drinking water from a potentially contaminated source in the forest are indicative of a parasitic infection, supporting the choice of Metronidazole for treatment.

Correct Answer: A

Rationale: The correct answer is A: Haemolytic streptococci. Hemolytic streptococci are known to cause serious infections in humans, including strep throat and skin infections. These bacteria have the potential to spread rapidly and cause epidemics. Bacilli are a broad category of bacteria and not all are necessarily harmful. Micrococci are commonly found on human skin and are generally harmless. Yeast fungi are also commonly found in the environment and are not typically associated with causing epidemics. Therefore, the presence of hemolytic streptococci in the air of a pharmacy indicates a direct epidemic danger due to their pathogenic nature and potential to cause widespread infections.

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.