Why Would It Be Important for the Kirby-Bauer Disc Diffusion

question 88

Multiple Choice

Why would it be important for the Kirby-Bauer disc diffusion test to use a standard concentration (number of cells in the sample) of each of the bacterial strains being tested?

• A) If you were to use one strain that was stationary phase (high concentration, replicating very slowly or not at all), and another strain that was just beginning log phase (low concentration but replicating quickly), you could see different results in the test, affecting your interpretation.
• B) Growth on the Mueller-Hinton agar plates utilized is very sensitive to the phase of the growth curve the bacteria are in when they are placed on the plate. If they are not in the log phase when they are placed on the plate, they will not grow and the test will be worthless.
• C) Antibiotic resistance is usually only manifested by bacteria that have achieved a very high concentration. It's important to use bacteria specifically at this particular point for disc diffusion testing.
• D) Antibiotics only work within a narrow range of cell concentrations. If you use a concentration that is too low or too high, you will get inaccurate measurements of the zone of inhibition.
• E) Bacteria only develop resistance when there are more than 1012 cells/ mL. If resistance is to be detected, the test must use at least this concentration of cells. If fewer cells are used, no zone of inhibition will develop.

Distinguish between muscles based on their roles in movements like forced inspiration or rotation.

Relate specific muscles to common conditions such as carpal tunnel syndrome.

Understand the structural anatomy related to muscle attachment on bones like humerus, metacarpal, and radius.

Understand the structure and purpose of positive and routine messages.

---

Definitions:

Output

The complete sum of outputs, whether goods or services, created by an enterprise, industry, or economic entity.

Marginal Revenue

The revenue enhancement a company experiences by selling another unit of a product or service.

Total Revenue

The total amount of money received by a firm from sales of its products or services, calculated as the quantity sold times the price per unit.

MC < MR

A condition in economic theory where marginal cost is less than marginal revenue, suggesting that increasing production would be profitable.