A note on gentamicin susceptibility testing: the validity of the MS-2 system and Rosco Neosensitabs agar diffusion

The MS-2 automated system was compared with Rosco Neosensitabs agar diffusion for the gentamicin susceptibility of a group of 267 organisms isolated from clinical material. With Rosco Neosensitabs agar diffusion agreement with reference minimal inhibitory concentrations was 98.5%, while with the MS-2 system it was 100% if calcium and magnesium-supplemented MS-2 broth was used.