ABSTRACT
Several investigators have demonstrated differences in aminoglycoside susceptibility when employing a variety of media. The aminoglycoside susceptibility of a strain may be determined by a variety of in vitro and in vivo methods. An in vivo method of susceptibility testing which is frequently employed in the pharmaceutical industry is the mouse protection test. While most clinical, research, and pharmaceutical laboratories routinely use Mueller-Hinton media when determining aminoglycoside susceptibility, it should be emphasized that variability still occurs because of differences in media constituents from one manufacturer to another. J. Klastersky and L. Debusscher reported that susceptibility testing of several compounds including aminoglycosides were significantly affected by the pH of the medium. For aminoglycosides, the percentage of drug bound to human serum and plasma proteins has been found to be relatively low. Perhaps the most discussed variable in the susceptibility testing of aminoglycosides is the concentration of divalent cations in the medium.
