Which of the statements below IS NOT CORRECT

Correct Answer: B

Rationale: The correct answer is B because live vaccines can potentially revert to a virulent form, although this is extremely rare. This is due to the live attenuated virus in the vaccine potentially mutating back to a more dangerous form. Live vaccines are designed to be weakened but there is a small risk of reversion. Therefore, statement B is not correct. A: This statement is correct as immunocompromised individuals may have adverse reactions to live vaccines due to their weakened immune system. C: This statement is correct as microbes with many serotypes can make it challenging to develop a vaccine that covers all variations. D: This statement is correct as side effects to vaccination, although usually mild and temporary, can occur in some individuals.

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.

Correct Answer: C

Rationale: Rationale: Metronidazole is the drug of choice for systemic amebiasis due to its high efficacy against Entamoeba histolytica. It has good tissue penetration and can treat intestinal, liver, and lung involvement. Quiniofone (A) has limited use and is not recommended for amebiasis. Enteroseptol (B) is not effective against systemic amebiasis. Tetracycline (D) is not the first-line treatment for amebiasis and has limited efficacy against Entamoeba histolytica.

Correct Answer: A

Rationale: The correct answer is A: Mycobacterium leprae. This bacterium is responsible for causing leprosy. Mycobacterium leprae is a slow-growing bacterium that affects the skin and nerves, leading to the characteristic symptoms of leprosy. Neisseria gonorrhoeae is a sexually transmitted bacterium causing gonorrhea. Streptococcus pneumoniae causes pneumonia and other respiratory infections. Clostridium perfringens is associated with food poisoning and gas gangrene. Therefore, the correct answer is A because Mycobacterium leprae specifically causes leprosy, while the other choices are associated with different diseases.

Correct Answer: A

Rationale: The correct answer is A: Tetanus. The patient's symptoms of muscle contractions, fever, and wound history suggest tetanus, caused by Clostridium tetani bacteria commonly found in soil. The spastic muscle contractions around the wound are classic for tetanus due to the neurotoxin produced by the bacteria. General weakness and headache are also common symptoms. B: Anthrax is unlikely as it presents with different symptoms such as skin lesions, respiratory symptoms, and gastrointestinal symptoms. C: Erysipelas is characterized by red, swollen patches on the skin, not consistent with the symptoms described. D: Gram-positive is not a specific diagnosis but a broad category of bacteria. Tetanus is caused by Clostridium tetani, which is a Gram-positive bacterium, but this choice does not provide a specific infection diagnosis.

Correct Answer: D

Rationale: The correct answer is D: Terminally. In Clostridium tetani, spores are located at the terminal end of the cell. This positioning helps the spores to be released easily when the cell lyses, aiding in the spread of the bacteria. Paracentrally (A) and centrally (C) would not be as efficient for spore release. Subterminally (B) is also incorrect as the spores are specifically located at the terminal end of the cell, not just near it.

Correct Answer: A

Rationale: The correct answer is A: BCG vaccination. The Mantoux test is used to detect tuberculosis infection. A negative reaction means the child is not infected. BCG vaccination is recommended for individuals without prior TB infection to prevent severe forms of the disease. Antitoxin and rabies vaccinations are not related to TB and are not indicated in this scenario. Repeating the Mantoux test is unnecessary since a negative result indicates absence of TB infection.

Correct Answer: B

Rationale: The correct answer is B: microvilli. Pili are hair-like structures found on the surface of some bacteria, while microvilli are microscopic cellular projections that increase surface area for absorption in cells like intestinal cells. Pili are involved in bacterial adhesion, while microvilli are important for nutrient absorption. Therefore, the correct answer is B. Incorrect choices: A: Fimbriae are short, thin appendages found on the surface of some bacteria, mainly used for adhesion. C: Cilia are hair-like structures found on the surface of some eukaryotic cells, often involved in movement or sensory functions. D: Flagella are long, whip-like appendages used for bacterial motility.

Correct Answer: B

Rationale: The correct answer is B (2). During glycolysis, one glucose molecule is broken down into two molecules of pyruvate. In this process, a net gain of 2 ATP molecules is produced through substrate-level phosphorylation. Specifically, ATP is generated during the conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate and during the conversion of phosphoenolpyruvate to pyruvate. The other choices are incorrect because the net gain of ATP molecules in glycolysis is not 1, 3, or 4; it is 2 based on the specific enzymatic reactions involved in the pathway.