- Mueller Hinton Agar is used to test the antibiotic susceptibility of fast-growing bacteria.
- TraceMedia™ Mueller Hinton Agar contains nutrient-rich components such as beef extract and acid hydrolysate of casein, providing amino acids, nitrogenous compounds, vitamins, and essential minerals for microbial growth.
- Starch acts as a protective colloid against toxic substances in the environment. Additionally, the medium contains a small amount of thymidine and thymine, which can inhibit the effect of sulfonamides and trimethoprim.
- The presence of divalent cations in the agar controls the activities of aminoglycosides, tetracycline, and colistin, especially for evaluating Pseudomonas aeruginosa.
- After incubation for the required time, observe bacterial growth on the surface of the plate and the zones of inhibition around antibiotic discs. The identification of isolated bacteria must be further confirmed using appropriate tests. If isolated colonies still appear, retesting is necessary.
- To measure the complete inhibition zones (including the antibiotic discs), invert the plate and hold it up to the light. Use a ruler graduated to millimeters to measure the diameter of the complete inhibition zones.
- The edge of the inhibition zone should be read from the area where bacterial growth is not visible to the naked eye. Faint or small colonies at the edge of the growth inhibition zone may only be visible under magnification and should be ignored.
- For interpreting the zone sizes, refer to CLSI M100 guidelines for each bacterial strain.