A bioluminescent method was proposed for rapid detection of viable Gram-positive bacteria based on a novel antibiotic-affinity strategy on a magnetic beads (MBs) platform. Daptomycin, a highly efficient lipopeptide antibiotic for Gram-positive bacteria, was used as a recognition agent to functionalize MBs. The daptomycin-functionalized MBs showed high capture and concentration efficiency for Gram-positive bacteria due to the strong binding between daptomycin and bacterial cell membrane in the presence of Ca2+ ion. The captured bacteria were lysed by hexadecyl trimethyl ammonium bromide solution, followed by a bioluminescent detection of the released intracellular adenosine triphosphate. Four Gram-positive bacteria, including Staphylococcus aureus, Streptococcus mutans, Bacillus subtilis and Staphylococcus epidermidis, were detected as model bacteria by this method. Under the optimal conditions, the bacteria could be detected within a linear range of 1.0 × 102-3.0 × 106 CFU mL-1, with a detection limit of 33 CFU mL-1. The whole detection procedure could be completed within 20 min. Gram-negative bacteria and dead Gram-positive bacteria showed negligible interference to the detection of viable Gram-positive bacteria. The proposed method was successfully applied to quantify the amount of viable Gram-positive bacteria in cheese, milk, lake water, human urine and physiological saline injection with acceptable recovery values ranging from 75.0% to 120.0%. The strategy possessed some advantages such as high sensitivity, short assay time and simple operation, thus showed great promise for food hygiene, environment monitoring, clinical diagnosis and drug safety.

中文翻译：

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使用达托霉素作为识别剂对活革兰氏阳性菌进行生物发光检测的抗生素亲和策略

基于磁珠 (MBs) 平台上的新型抗生素亲和性策略，提出了一种生物发光方法，用于快速检测活革兰氏阳性菌。达托霉素是一种用于革兰氏阳性菌的高效脂肽抗生素，被用作识别剂以功能化 MB。由于在 Ca2+ 离子存在下达托霉素与细菌细胞膜之间的强结合，达托霉素功能化的 MB 对革兰氏阳性细菌显示出高捕获和浓缩效率。捕获的细菌用十六烷基三甲基溴化铵溶液裂解，然后对释放的细胞内三磷酸腺苷进行生物发光检测。四种革兰氏阳性菌，包括金黄色葡萄球菌、变形链球菌、枯草芽孢杆菌和表皮葡萄球菌，通过该方法检测为模型细菌。在最佳条件下，可在1.0×102-3.0×106 CFU mL-1的线性范围内检出细菌，检出限为33 CFU mL-1。整个检测过程可在20分钟内完成。革兰氏阴性菌和死革兰氏阳性菌对活革兰氏阳性菌检测的干扰可以忽略不计。所提出的方法已成功应用于量化奶酪、牛奶、湖水、人尿和生理盐水注射液中革兰氏阳性菌的数量，可接受的回收率范围为 75.0% 至 120.0%。该策略具有灵敏度高、检测时间短、操作简单等优点，在食品卫生、环境监测、临床诊断和药品安全等方面具有广阔的应用前景。