Microbiology A Systems Approach Test Bank

Microbiology A Systems Approach Test Bank Related

Review Microbiology A Systems Approach Test Bank related questions and content

Basing upon the data of laboratory assessment of sanitary state of soil in a certain territory, the soil was found to be low-contaminated according to the sanitary indicative value; contaminated according to the coli titer; low-contaminated according to the anaerobe titer (Cl. perfringens). This is indicative of:

  • A. Fresh fecal contamination
  • B. Old fecal contamination
  • C. Insufficient intensity of soil humification
  • D. Constant entry of organic protein contaminations
Correct Answer: A

Rationale: Step 1: The soil is low-contaminated according to the sanitary indicative value, which indicates that the contamination is recent.
Step 2: The soil is contaminated according to coli titer, suggesting the presence of coliform bacteria typically found in fresh fecal matter.
Step 3: The soil is low-contaminated according to the anaerobe titer (Cl. perfringens), which is an indicator of recent fecal contamination.
Step 4: Based on the above steps, the correct answer is A: Fresh fecal contamination, as the presence of coliform bacteria and recent anaerobe titer levels point to recent fecal contamination.
Summary:
B: Old fecal contamination - Incorrect because the indicators suggest recent contamination.
C: Insufficient intensity of soil humification - Incorrect as it is not related to the specific indicators mentioned in the question.
D: Constant entry of organic protein contaminations - Incorrect as the indicators point towards fecal contamination, not protein

You may also like to solve these questions

A 40 year old man noticed a reddening and an edema of skin in the area of his neck that later developed into a small abscess. The incised focus is dense, yellowish-green. The pus contains white granules. Histological examination revealed drusen of a fungus, plasmatic and xanthome cells, macrophages. What type of mycosis is the most probable?

  • A. Actinomycosis
  • B. Aspergillosis
  • C. Candidosis
  • D. Sporotrichosis
Correct Answer: D

Rationale: The correct answer is D: Sporotrichosis. Sporotrichosis is caused by the fungus Sporothrix schenckii, which commonly presents as a subcutaneous infection. In the given case, the presence of a small abscess with yellowish-green pus containing white granules is indicative of sporotrichosis. The histological examination showing drusen of a fungus, plasmatic and xanthome cells, and macrophages further supports the diagnosis of sporotrichosis.

Choice A: Actinomycosis is a bacterial infection caused by Actinomyces species, not a fungal infection.
Choice B: Aspergillosis is caused by Aspergillus species and typically presents as a pulmonary infection, not a subcutaneous abscess as described in the case.
Choice C: Candidosis is caused by Candida species and usually presents as mucocutaneous infections, not a subcutaneous abscess with the

Which of the following is a preferred mode of transmission of HIV from a mother to a child

  • A. during delivery through mixing of blood
  • B. during pregnancy through placenta
  • C. via breastmilk during lactation
  • D. All of the above
Correct Answer: D

Rationale: The correct answer is D because HIV can be transmitted from a mother to a child through multiple modes: during delivery through mixing of blood, during pregnancy through the placenta, and via breastmilk during lactation. Each mode presents a risk of transmission due to the presence of the virus in bodily fluids. Therefore, all of the above options are preferred modes of transmission for HIV from a mother to a child. Choices A, B, and C alone do not fully encompass all the possible routes of transmission, making them incorrect.

A patient in the oral surgery department has got purulent complication. Bacteriological analysis of the wound material found a culture that produces cyan pigment. What microorganism is the most probable causative agent?

  • A. Pseudomonas aeruginosa
  • B. Proteus vulgaris
  • C. Bacillus subtilis
  • D. Klebsiella pneumoniae
Correct Answer: A

Rationale: The correct answer is A: Pseudomonas aeruginosa. Pseudomonas aeruginosa is known for producing a bluish-green pigment called pyocyanin, which presents as a cyan pigment. This bacterium is commonly associated with wound infections and is often found in oral surgery complications. Proteus vulgaris (B) and Klebsiella pneumoniae (D) are not typically associated with cyan pigment production, making them less likely causative agents. Bacillus subtilis (C) is not known to produce cyan pigment and is not a common pathogen in wound infections. Therefore, based on the presence of cyan pigment and the clinical context of an oral surgery complication, Pseudomonas aeruginosa is the most probable causative agent.

What is the role of coagulase in bacteria like Staphylococcus aureus?

  • A. It facilitates adhesion to surfaces
  • B. It breaks down red blood cells
  • C. It forms clots to evade immune responses
  • D. It aids in antibiotic resistance
Correct Answer: C

Rationale: The correct answer is C because coagulase helps bacteria like Staphylococcus aureus to form clots, allowing them to evade the host immune response. This mechanism helps the bacteria to hide from the immune system and establish infection.

A. Adhesion to surfaces is usually facilitated by other factors like adhesins.
B. Breaking down red blood cells is not a function of coagulase.
D. Antibiotic resistance is typically mediated by other mechanisms like efflux pumps or enzymatic inactivation, not coagulase.

The food preparation process in which not all microorganisms are killed, but the number of microbes capable of spoiling the food or causing disease is reduced, is called

  • A. sanitation.
  • B. pasteurization.
  • C. disinfection.
  • D. purification.
Correct Answer: B

Rationale: The correct answer is B: pasteurization. This process involves heating food to a specific temperature to kill harmful bacteria while preserving the flavor and quality of the food. Sanitation (A) refers to maintaining cleanliness to prevent contamination. Disinfection (C) involves killing most, but not all, microbes on surfaces. Purification (D) typically refers to the process of removing impurities, not specifically targeting microbes. In this case, pasteurization best describes the process of reducing harmful microbes in food without completely eliminating all microorganisms.

Copyright © 2025 Nokea. All rights reserved.