Microbiology Chapter 11 Test Bank

Microbiology Chapter 11 Test Bank Related

Review Microbiology Chapter 11 Test Bank related questions and content

Dwellers of a village noticed mass mortality of rats in some farms. It was suspected that the animals might have died from plague. What postmortal analyses should be conduced in order to establish the causative agent of the infection as soon as possible?

  • A. Ring precipitation reaction
  • B. Agglutination reaction
  • C. Passive agglutination reaction
  • D. Neutralization reaction
Correct Answer: B

Rationale: The correct answer is B: Agglutination reaction. This test is commonly used to detect specific antibodies or antigens. In this case, it can be used to detect plague antigens in the rat tissues or antibodies in the villagers. This test is rapid, sensitive, and can help establish the presence of the causative agent quickly.

A: Ring precipitation reaction is not typically used for diagnosing plague and is more commonly used in other types of infections.

C: Passive agglutination reaction is not specific for plague and is more commonly used for detecting specific antibodies in diseases like syphilis.

D: Neutralization reaction is not typically used for diagnosing plague and is more commonly used to determine the presence of neutralizing antibodies in viral infections.

You may also like to solve these questions

In which of the following GIT infections, the bacteria adhere to the intestine wall and produce toxins:

  • A. Shigella spp.
  • B. Enteropathogenic E.coli (EPEC)
  • C. Salmonella spp.
  • D. Vibrio cholerae
Correct Answer: B

Rationale: Rationale:
1. Enteropathogenic E.coli (EPEC) adheres to the intestinal wall using bundle-forming pili.
2. EPEC produces toxins that disrupt cell structure and function, leading to diarrhea.
3. Shigella spp. invade intestinal cells, Salmonella spp. invade and multiply within cells, and Vibrio cholerae produces cholera toxin causing profuse watery diarrhea.
Summary:
A, C, and D choices are incorrect because they do not specifically adhere to the intestine wall and produce toxins like EPEC does.

Which one of the following statements about Rickettsiae is true?

  • A. They do not form spores, capsules and flagella
  • B. They have slim glycocalyx layer
  • C. They have bipolar fimbriae
  • D. All of the above
Correct Answer: D

Rationale: Rationale:
1. Rickettsiae are obligate intracellular bacteria, hence they do not form spores, capsules, or flagella.
2. They have a slim glycocalyx layer, aiding in attachment to host cells.
3. Bipolar fimbriae are structures that help in adhesion to host cells.
Therefore, all statements (A, B, and C) are true for Rickettsiae, making option D the correct answer. Other choices are incorrect as they do not accurately describe the characteristics of Rickettsiae.

Examination of duodenal contents revealed some pyriform protozoa with twin nuclei and four pairs of flagella. There were two supporting filaments between the nuclei and a suctorial disc on the ventral side. What representative of protozoa was revealed in this patient?

  • A. Lamblia
  • B. Toxoplasma
  • C. Leishmania
  • D. Intestinal trichomonad
Correct Answer: A

Rationale: Rationale for Correct Answer A (Lamblia):
1. Pyriform protozoa with twin nuclei, four pairs of flagella, and a suctorial disc match the characteristics of Giardia lamblia.
2. The presence of two supporting filaments between the nuclei is a unique feature of Giardia lamblia.
3. Giardia lamblia is known to infect the duodenum and cause symptoms such as diarrhea and abdominal pain.

Summary of Incorrect Choices:
B: Toxoplasma - Toxoplasma gondii is not characterized by four pairs of flagella or supporting filaments in the nuclei.
C: Leishmania - Leishmania species do not typically have the described morphology or location in the duodenum.
D: Intestinal trichomonad - Intestinal trichomonads do not exhibit the specific features mentioned in the question, such as twin nuclei and supporting filaments.

Researchers of a bacteriological laboratory examine tinned meat for botulinic toxin. For this purpose a group of mice was injected with an extract of the material under examination and antitoxic antibotulinic serum of A, B, E types. A control group of mice was injected with the same extract but without antibotulinic serum. What serological reaction was applied?

  • A. Neutralization
  • B. Precipitation
  • C. Complement binding
  • D. Double immune diffusion
Correct Answer: A

Rationale: The correct answer is A: Neutralization. In this experiment, the researchers used antitoxic antibotulinic serum of different types to neutralize the botulinic toxin in tinned meat extract injected into mice. Neutralization is the process of rendering a toxin harmless by combining it with specific antibodies. The purpose of injecting the antitoxic serum was to neutralize the toxin and prevent it from causing harm to the mice. This serological reaction of neutralization directly aligns with the objective of the experiment.

Summary of other choices:
B: Precipitation - Precipitation involves the formation of a visible insoluble complex when an antigen reacts with its corresponding antibody. This process was not described in the scenario.
C: Complement binding - Complement binding involves the activation of the complement system by antigen-antibody complexes. This was not the main focus of the experiment described.
D: Double immune diffusion - This technique is used to detect the presence of specific antigens or antibodies

A patient presents with a history of diarrhea of several weeks duration. Which of the following may be the cause?

  • A. Yersinia enterocolitica
  • B. Bordetella pertussis
  • C. Neisseria meningitidis
  • D. Corynebacterium diphtheria
Correct Answer: A

Rationale: Rationale:
- Yersinia enterocolitica is a common cause of diarrhea due to contaminated food or water.
- It typically presents with symptoms such as abdominal pain, fever, and diarrhea.
- The other choices are unlikely causes of prolonged diarrhea, as Bordetella pertussis causes whooping cough, Neisseria meningitidis causes meningitis, and Corynebacterium diphtheria causes diphtheria.

Copyright © 2025 Nokea. All rights reserved.