Diffusion and dilution tests that expose pathogens to antimicrobials are designed to determine __________ .


a. the spectrum of action of a drug
b. which drug is most effective against a particular pathogen
c. the amount of a drug to use against a particular pathogen
d. both b and c

Verified step by step guidance

1. Understand the purpose of diffusion and dilution tests in microbiology, which is to evaluate the effectiveness of antimicrobial agents against pathogens.
2. Recognize that these tests help determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of a drug, which are crucial for assessing drug effectiveness.
3. Consider that the tests can identify which drug is most effective against a particular pathogen by comparing the results of different antimicrobials.
4. Acknowledge that these tests also help determine the appropriate dosage of a drug needed to inhibit or kill a pathogen, ensuring effective treatment.
5. Conclude that the correct answer involves both identifying the most effective drug and determining the appropriate dosage, which corresponds to option d.

Key Concepts

Antimicrobial Spectrum of Action

The spectrum of action refers to the range of bacteria that a particular antimicrobial agent can effectively target. Antimicrobials can be broad-spectrum, affecting a wide variety of pathogens, or narrow-spectrum, targeting specific types. Understanding this concept is crucial for selecting the appropriate drug for treatment.

Minimum Inhibitory Concentration (MIC)

The Minimum Inhibitory Concentration (MIC) is the lowest concentration of an antimicrobial that prevents visible growth of a microorganism. MIC is determined through dilution tests and is essential for assessing the effectiveness of a drug against a specific pathogen, guiding dosage decisions in clinical settings.

Antimicrobial Susceptibility Testing

Antimicrobial susceptibility testing involves methods like diffusion and dilution tests to evaluate how susceptible a pathogen is to various antimicrobial agents. This testing helps clinicians choose the most effective treatment options and is vital for combating antibiotic resistance by ensuring appropriate drug use.