In 8 days after a surgery the patient develops tetatus. The surgeon suspects this condition to be caused by suture material contaminated by tetanus agent. The material is delivered to a bacteriological laboratory. What nutrient medium is required for primary inoculation of the suture material?

Correct Answer: D

Rationale: The correct answer is D, Kitt-Tarozzi medium. This medium is specifically designed for the isolation and cultivation of Clostridium tetani, the bacteria responsible for tetanus. The other options, Sabouraud agar, Endo agar, and Hiss medium, are not suitable for the growth of Clostridium tetani. Sabouraud agar is used for fungal cultures, Endo agar is a selective medium for enteric bacteria, and Hiss medium is used for the cultivation of anaerobic bacteria other than Clostridium tetani. Therefore, the Kitt-Tarozzi medium is the most appropriate choice for isolating and identifying the tetanus agent in this scenario.

Correct Answer: B

Rationale: The correct answer is B because the nucleocapsid of viruses is composed of the genome (genetic material) and the capsid (protein coat). The genome contains the viral genetic information, while the capsid protects the genome and helps in viral attachment and entry into host cells. Choice A is incorrect because the envelope is not part of the nucleocapsid but surrounds the capsid in some viruses. Choice C is incorrect as spikes are surface proteins on the viral envelope, not part of the nucleocapsid. Choice D is also incorrect because the envelope is external to the capsid and genome in many viruses.

Correct Answer: A

Rationale: The correct answer is A because in the lytic cycle, the bacteriophage destroys the host cell upon release, whereas in the lysogenic cycle, the phage integrates its DNA into the host genome without killing the host immediately. This integration may lead to the destruction of the host cell at a later stage. Choice B is incorrect as lytic phages do destroy the host cell. Choice C is incorrect as the two cycles have distinct mechanisms. Choice D is incorrect as there are clear differences between the lytic and lysogenic cycles.

Correct Answer: D

Rationale: The correct answer is D, "All of the above." Escherichia coli is the most common bacteria causing UTIs due to its ability to colonize the urinary tract. Salmonella enterica and Neisseria gonorrhoeae are not typically associated with UTIs. Therefore, by process of elimination, since A is correct, B and C are incorrect.

Correct Answer: C

Rationale: Rifampicin is the correct answer because it is a first-line antibiotic for treating pulmonary tuberculosis. It has excellent bactericidal activity and penetrates well into lung tissues where the infection is located. Rifampicin is also known for preventing the development of resistance. Tetracycline (A) and Furasolidone (B) are not commonly used for tuberculosis treatment. Bactrim (D) is a combination of sulfamethoxazole and trimethoprim, not effective for tuberculosis treatment.

Correct Answer: A

Rationale: The correct answer is A: Volutin granules. Volutin granules are metachromatic granules that stain dark blue with methylene blue or Leishman stain. In diphtheria-causing bacteria, Corynebacterium diphtheriae, these granules are typically seen as yellow rods with dark blue thickenings on their ends when stained. Volutin granules are storage inclusions composed of polymetaphosphate that serve as an energy reserve for the bacteria. The presence of these granules in the detected microorganisms indicates the characteristic feature of Corynebacterium diphtheriae. Summary of other choices: B: Plasmids are extrachromosomal DNA molecules that are not typically visible on stained smears. C: Capsules are outer protective layers that are not visible on stained smears. D: Spores are reproductive structures formed by certain bacteria, not typically seen in Corynebacterium diphtheriae.

Correct Answer: B

Rationale: The correct answer is B: Jenner. Edward Jenner performed the first vaccination against smallpox in 1796 by using cowpox virus to immunize individuals. He observed that milkmaids who had contracted cowpox did not get smallpox, leading to the development of the smallpox vaccine. Pasteur is known for germ theory, Semmelweis for handwashing in healthcare, and Koch for identifying the causative agents of diseases. However, none of them performed the first smallpox vaccination like Jenner.

Correct Answer: B

Rationale: The correct answer is B: BKV. BK virus can cause hemorrhagic cystitis in immunocompromised patients by infecting the urinary tract. It primarily affects the renal tubular epithelial cells, leading to hemorrhagic cystitis. EBV (A) causes infectious mononucleosis, HSV1 (C) causes oral and genital herpes, and JCV (D) causes progressive multifocal leukoencephalopathy, none of which are associated with hemorrhagic cystitis.

Correct Answer: B

Rationale: The correct answer is B: Motility. Bacterial flagella function in providing motility to bacteria, allowing them to move towards nutrients or away from harmful substances. Flagella are long, whip-like appendages that rotate to propel the bacteria through their environment. Incorrect choices: A: Protein synthesis - Bacterial flagella are not involved in protein synthesis. C: Adhesion to surfaces - While some bacteria use flagella for attachment, their main function is not adhesion. D: DNA replication - Flagella do not play a role in DNA replication, which occurs in the bacterial cell's nucleus.