The detection and quantification of Legionella pneumophila (responsible for legionnaire's disease) in water samples can be achieved by various methods. However, the culture‐based ISO 11731:2017, which is based on counts of colony‐forming units per ml (CFU·ml^‐1) is still the gold standard for quantification of Legionella species (spp.). As a powerful alternative, we propose real‐time monitoring of the growth of L. pneumophila using an isothermal microcalorimeter (IMC). Our results demonstrate that, depending on the initial concentration of L. pneumophila, detection times of 24–48 h can be reliably achieved. IMC may, therefore, be used as an early warning system for L. pneumophila contamination. By replacing only visual detection of growth by a thermal sensor, but otherwise maintaining the standardized protocol of the ISO 11731:2017, the new procedure could easily be incorporated into existing standards. The exact determination of the beginning of metabolic heat is often very difficult because at the beginning of the calorimetric signal the thermal stabilization and the metabolic heat development overlap. Here, we propose a new data evaluation based on the first derivation of the heat flow signal. The improved evaluation method can further reduce detection times and significantly increase the reliability of the IMC approach.

中文翻译：

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使用等温微量热法和改进的评估方法对嗜肺军团菌进行基于培养的快速检测。

水样中嗜肺军团菌（军团菌病的致病菌）的检测和定量可以通过多种方法实现。然而，基于每毫升菌落形成单位 (CFU·ml ^{‐1 ) 计数的基于培养的 ISO 11731:2017 仍然是}军团菌 (spp.)定量的黄金标准。作为一个强大的替代方案，我们建议实时监测L的生长。 使用等温微量热计 (IMC) 检测嗜肺杆菌。我们的结果表明，取决于L的初始浓度。对于嗜肺杆菌，可以可靠地实现 24-48 小时的检测时间。因此，IMC 可用作嗜肺军团菌污染的早期预警系统。通过仅用热传感器取代视觉生长检测，但保持 ISO 11731:2017 的标准化协议，新程序可以轻松纳入现有标准。准确确定代谢热的开始通常非常困难，因为在量热信号开始时，热稳定和代谢热产生重叠。在这里，我们提出了一种基于热流信号一阶导数的新数据评估。改进的评估方法可以进一步减少检测时间并显着提高IMC方法的可靠性。