Inhibition test
The inhibition zone test (or platelet test ) is a method of testing the sensitivity of bacteria to certain antibiotics or other inhibitors . In addition to the semiquantitative dilution series, it is a method for creating an antibiogram .
For this purpose, material containing the pathogen is spread on a nutrient medium . Small pieces of filter paper are placed on the bacterial layer, each of which is soaked with a certain antibiotic. The antibiotics diffuse into the agar layer . If the bacterium is sensitive to the respective antibiotic, the bacterial growth is inhibited and clearly visible zones of inhibition arise. A zone of inhibition is the clear area between the edge of the filter leaf and the beginning of a cell colony. If there is no inhibition zone around a piece of filter paper, then there is resistance to the antibiotic.
Depending on the size of the inhibition zone, a distinction is made between resistant, sensitive and insensitive bacteria.
The principle of the Hemmhof test is used in the Optochin test and Baci / CAMP test .