Dornbusch K
Scand J Infect Dis Suppl. 1980;Suppl 23:46-53.
The composition of the growth medium, especially the presence of divalent cations Mg2+ and Ca2+, affects the susceptibility of bacteria to aminoglycoside antibiotics. Regression lines were calculated for gentamicin and netilmicin with 146 fresh clinical isolates and by the use of the standardized disc diffusion and agar dilution methods on PDM-agar or Mueller-Hinton agar. At the break-point less than or equal to 4 micrograms/ml, denoting susceptibility different zones of inhibition were obtained on the different agar media. When performing regression line analysis from tests with 56 isolates by the disc diffusion method on Mueller-Hinton agar versus MIC's in Mueller-Hinton broth, the resulting lines were different from those when performing the MIC's in agar. Furthermore, the bacteria were twofold or more susceptible in unsupplemented Mueller-Hinton broth than on Mueller-Hinton agar.
生长培养基的组成，尤其是二价阳离子Mg2+和Ca2+的存在，会影响细菌对氨基糖苷类抗生素的敏感性。使用146株新鲜临床分离株，通过在PDM琼脂或穆勒-欣顿琼脂上采用标准化纸片扩散法和琼脂稀释法，计算了庆大霉素和奈替米星的回归线。在断点小于或等于4微克/毫升（表示敏感）时，在不同的琼脂培养基上获得了不同的抑菌圈。当通过纸片扩散法在穆勒-欣顿琼脂上对56株分离株进行测试并与穆勒-欣顿肉汤中的最低抑菌浓度（MIC）进行回归线分析时，所得的线与在琼脂中进行MIC测试时不同。此外，在未补充的穆勒-欣顿肉汤中，细菌的敏感性是在穆勒-欣顿琼脂上的两倍或更高。
