Principles of Antimicrobial Therapy (Pharmacology Ch 43)

Question 1

Antimicrobial therapy

“antibiotic therapy”

Answer 1

-use of medications to treat infections caused by bacteria, viruses, and fungi

Question 2

Bactericidal medications

Answer 2

-directly lethal to the micro-organism

Question 3

Bacteriostatic medications

Answer 3

-slow the growth of the micro-organism, but it is actually destroyed by the client’s immune system response of phagocytic cells (macrophages, neutrophils) to eliminate the bacteria

Question 4

Gram stain

Answer 4

-an aspirate of the body fluid is examined under a microscope, where micro-organisms can be identified directly

Question 5

Culture of the fluid

Answer 5

• the aspirate is applied to culture medium, and colonies of the micro-organism are grown over several days
• may be preferable to gram stain in cases where positive id cannot be made by gram stain
• obtain PRIOR to treatment w/ antibiotics

Question 6

Sensitivity of the Micro-organism to the antimicrobial

Answer 6

• for organisms where resistance is common, a test for sensitivity of the organism to various antimicrobials is performed
• disk diffusion test (Kirby-Bauer test) = most common. Degree of medication sensitivity is determined by amount of bacteria-free zone on the disk

Question 7

Minimum inhibitory concentration (MIC)

Answer 7

-the amount of antibiotic to completely inhibit bacterial growth but does not kill the bacteria

Question 8

Minimum bactericidal concentration (MBC)

Answer 8

-the lowest concentration of the antibiotic that kills 99.9% of the bacteria