For more than a century, blood agar plates have been the only test for beta-hemolysis. Although blood agar cultures are highly predictive for bacterial pathogens, they are too slow to yield actionable information. Here, we show that beta-hemolytic pathogens are able to lyse and release fluorophores encapsulated in sterically stabilized liposomes whereas alpha and gamma-hemolytic bacteria have no effect. By analyzing fluorescence kinetics, beta-hemolytic colonies cultured on agar could be distinguished in real time with 100% accuracy within 6 h. Additionally, end point analysis based on fluorescence intensity and machine-extracted textural features could discriminate between beta-hemolytic and cocultured control colonies with 99% accuracy. In broth cultures, beta-hemolytic bacteria were detectable in under an hour while control bacteria remained negative even the next day. This strategy, called beta-hemolysis triggered-release assay (BETA) has the potential to enable the same-day detection of beta-hemolysis with single-cell sensitivity and high accuracy.

中文翻译：

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Beta-溶血细菌选择性触发脂质体裂解，实现快速，准确的病原体检测

一个多世纪以来，血琼脂平板一直是进行β-溶血的唯一测试。尽管血琼脂培养物可高度预测细菌病原体，但它们太慢而无法产生可操作的信息。在这里，我们表明，β-溶血性病原体能够溶解并释放封装在空间稳定脂质体中的荧光团，而α和γ-溶血性细菌则没有作用。通过分析荧光动力学，可以在6小时内以100％的准确度实时区分培养在琼脂上的β-溶血菌落。此外，基于荧光强度和机器提取的纹理特征的终点分析可以以99％的准确度区分β-溶血和共培养的对照菌落。在肉汤文化中 在不到一个小时的时间内即可检测到β-溶血细菌，而对照细菌甚至在第二天仍为阴性。这种称为β溶血触发释放测定（BETA）的策略具有以单细胞敏感性和高精度实现当日检测β溶血的潜力。