Hi, in my project I am doing antimicrobial susceptibility testing. I have done both disk diffusion and broth microdilution for amikacin susceptibility testing for Acinetobacter baumannii and my results does not agree. My disk diffusion states all three my isolates are resistance and my broth microdilution states that the 1st isolate is susceptible, the 2nd is susceptible/intermediate and the 3rd is resistant. I have performed the disk diffusion twice and BMD 4 times. The 1st and 2nd isolates results vary in their MIC in the 4 BMD, they are not consistent. I did this BMD the same way as the CSLI recommend and for gentamicin and tobramycin and they worked. Any idea why my amikacin BMD will not work?

Thanks!