A fluorogenic substrate of beta-lactamases and its potential as a probe to detect the bacteria resistant to the third-generation oxyimino-cephalosporins.

We devised and synthesized a fluorogenic substrate of β-lactamases as a probe to detect the activity of the enzymes. Fluorescence of the probe emitted upon treatment of a β-lactamase and increased proportionally to the concentration of the enzyme, demonstrating its sensing property for the activity of the enzyme. We also showed that the probe could be utilized to assay the enzyme and to determine kinetic parameters of the enzyme. Moreover, the probe was able to detect resistance to the third-generation oxyimino-cephalosporin-derived antibiotics such as cefotaxime and ceftazidime. In particular, the probe could identify the ceftazidime-resistance in bacteria that was not detectable using conventional pH-sensing materials, indicating the practical utility of the probe.