Afb Mtb - Pas Disk Diffusion Infected Tissue

4-Aminosalicylic acid, commonly known as PAS, is an antibiotic used to treat tuberculosis. This organic compound has been use since the 1940s for the treatment of inflammatory bowel diseases (IBDs), where it has shown greater potency in Ulcerative Colitis and Crohn's disease. It is thought to act via NF-_B (nuclear factor-kappa B) inhibition and free radical scavenging. 5-Aminosalicylic acid, sold under the name mesalazine, is a closely related compound that also has medical uses. A specific concentration of organism from a culture isolate is applied to an agar plate. Discs of absorbent material to which specific concentrations of antibiotic have been added are placed on the agar. The agar plate is incubated to allow the isolate to grow on the plate in the presence of the antibiotic. If the organism grows to the edge of the impregnated disc, the organism is resistant to that antibiotic. If an area surrounds the disc where growth of the organism has be inhibited, the organism may be susceptible to the antibiotic on the disc. The length of area of inhibition can be measured and compared to standards to determine if the organism is susceptible, intermediate, or resistant to the antibiotic.