Antibiotic Susceptibility Testing Methods 1) Kirby Bauer Disk Diffusion: disks impregnanted w/ Abx → circular gradient → zone of inhibition. x MIC 2) Broth microdilution: Abx in 2-fold dilutions in 96-well plate. ✓ MIC 3) Gradient diffusion (E test): Hybrid between disk diffusion & broth microdilution. Strip sprayed w/abx gradient → ellipse meets strip ✓ MIC 4) Automated testing. May use abx dilutions or few abx concentrations + algorithms → standardized breakpoints to determine ✓ MIC Infectious Diseases Fellows Network @ID_fellows #Antibiotic #Sensitivity #Susceptibility #Testing #laboratory #microbiology
