Haag R, Lexa P, Werkhäuser I
Antimicrob Agents Chemother. 1986 May;29(5):765-8. doi: 10.1128/AAC.29.5.765.
Liquid cultures of a Pseudomonas aeruginosa strain in Mueller-Hinton broth diluted at rates higher than the bacterial growth rate showed the expected decrease in CFU only for 1 to 2 h. Later the CFU started to increase. This phenomenon can be explained by a hypothesis that assumes that the bacteria multiply in two different compartments. From the first compartment, which comprises bacteria homogeneously distributed in the broth, cells are eliminated at a rate that is dependent on the dilution and growth rates. Concomitantly, the second compartment is formed as a nondilutable adherent population on the surface of the culture vessel. Eventually, only cells stemming from that population appeared in the medium and were subsequently diluted. This hypothesis can be described mathematically by a linear combination of two exponential functions. The calculated values fit the experimental data well. Because similar CFU versus time curves were also found with other strains, care should be taken in interpreting results of experiments performed in liquid cultures and evaluated in terms of CFU. One should bear in mind that within a liquid culture an adherent population may exist, which differs in size according to selective influences (dilution, addition of antibiotics, etc.). This may give rise to artificial and unexpected results.
在穆勒 - 欣顿肉汤中以高于细菌生长速率的稀释率对铜绿假单胞菌菌株进行液体培养时，仅在1至2小时内观察到预期的菌落形成单位（CFU）减少。之后CFU开始增加。这种现象可以用一种假设来解释，该假设认为细菌在两个不同的隔室中繁殖。在第一个隔室中，细菌均匀分布在肉汤中，细胞以取决于稀释率和生长速率的速率被清除。与此同时，第二个隔室形成为培养容器表面上不可稀释的附着群体。最终，只有源自该群体的细胞出现在培养基中并随后被稀释。这个假设可以用两个指数函数的线性组合进行数学描述。计算值与实验数据拟合良好。由于在其他菌株中也发现了类似的CFU随时间变化的曲线，因此在解释液体培养实验结果并根据CFU进行评估时应谨慎。应记住，在液体培养中可能存在附着群体，其大小根据选择性影响（稀释、添加抗生素等）而有所不同。这可能会导致人为的和意想不到的结果。
