McGraw Hill Microbiology Test Bank

McGraw Hill Microbiology Test Bank Related

Review McGraw Hill Microbiology Test Bank related questions and content

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?

  • A. Sabouraud agar
  • B. Endo agar
  • C. Hiss medium
  • D. Kitt-Tarozzi medium
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.

You may also like to solve these questions

Which of the following scientists performed the first vaccination against smallpox?

  • A. Pasteur
  • B. Jenner
  • C. Semmelweis
  • D. Koch
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.

The bacteria that cause Lyme disease is:

  • A. Treponema pallidum
  • B. Borrelia burgdorferi
  • C. Leptospira interrogans
  • D. Rickettsia rickettsii
Correct Answer: B

Rationale: The correct answer is B: Borrelia burgdorferi. Borrelia burgdorferi is the bacteria responsible for causing Lyme disease. It is transmitted to humans through the bite of infected black-legged ticks. Treponema pallidum causes syphilis, Leptospira interrogans causes leptospirosis, and Rickettsia rickettsii causes Rocky Mountain spotted fever. Borrelia burgdorferi is specifically associated with Lyme disease due to its transmission through tick bites and the characteristic symptoms it causes.

Bacterial endotoxins are:

  • A. proteins in the cell wall
  • B. secreted into the environment
  • C. components of the gram-positive cell wall
  • D. components of the gram-negative cell wall
Correct Answer: D

Rationale: The correct answer is D: components of the gram-negative cell wall. Bacterial endotoxins are lipopolysaccharides found in the outer membrane of gram-negative bacteria. They are released upon bacterial cell lysis and can cause severe immune responses.

A: Proteins in the cell wall - This is incorrect because endotoxins are not proteins but rather lipopolysaccharides.
B: Secreted into the environment - Endotoxins are not actively secreted but are released upon cell death or lysis.
C: Components of the gram-positive cell wall - Gram-positive bacteria do not have an outer membrane with lipopolysaccharides, so endotoxins are not found in the gram-positive cell wall.

What is the most appropriate method for diagnosis of listeriosis

  • A. cultivating on artificial media and biochemical identification
  • B. serological diagnosis with ELISA
  • C. serological diagnosis with agglutination hype Widal
  • D. cultivating in cell cultures
Correct Answer: A

Rationale: The correct answer is A: cultivating on artificial media and biochemical identification. This method is appropriate for diagnosing listeriosis because it allows for the isolation and growth of Listeria species on selective media, followed by biochemical tests to confirm the identity. Serological diagnosis with ELISA (choice B) is not as specific for Listeria and may yield false positives. Choice C, serological diagnosis with agglutination hype Widal, is not typically used for listeriosis diagnosis. Cultivating in cell cultures (choice D) is not the primary method for diagnosing listeriosis as it is less specific compared to cultivating on artificial media and biochemical identification.

Which of the following bacteria produce endotoxins?

  • A. Streptococcus pneumoniae
  • B. Clostridium tetani
  • C. Escherichia coli
  • D. Staphylococcus aureus
Correct Answer: C

Rationale: The correct answer is C: Escherichia coli. E. coli is a gram-negative bacterium, which means it has an outer membrane containing lipopolysaccharides (LPS), also known as endotoxins. Endotoxins are released when the bacterium is destroyed, causing an inflammatory response.

Streptococcus pneumoniae (choice A) is a gram-positive bacterium and does not produce endotoxins. Clostridium tetani (choice B) produces exotoxins, not endotoxins. Staphylococcus aureus (choice D) is also a gram-positive bacterium and does not produce endotoxins.

In summary, E. coli is the correct answer because it is a gram-negative bacterium that produces endotoxins, while the other choices are gram-positive bacteria that do not produce endotoxins.

Copyright © 2025 Nokea. All rights reserved.