Sensitivity testing of bacteria to ceftriaxone using discs with different amounts of antibiotic

Studies were performed to compare the results of sensitivity testing of bacteria to ceftriaxone using discs containing 10, 20, 30 and 40 micrograms of the antibiotic. The highest correlation between diameters of zone inhibition and MIC values was found with discs containing 30 micrograms of ceftriaxone. The lowest percentage of false results was also obtained with 30 micrograms discs.