Rapid antibiotic susceptibility determination by fluorescence lifetime tracking of bacterial metabolism

Metabolic Imaging Study. In this study, we utilize NAD(P)H FLIM analysis to rapidly assess metabolic changes of bacterial cells in response to antibiotic challenges. Using susceptible, resistant, and clinical isolates of Escherichia coli as model strains, we characterize dynamic changes in metabolic state during exposure to bacteriostatic (tetracycline, chloramphenicol) and bactericidal (gentamicin) antibiotics. By tracking shifts in FLIM signal as a function of time and antibiotic concentration, we successfully identified resistant and susceptible phenotypes in under an hour and validated these results with conventional growth-based assays. These results demonstrate that FLIM is a viable method for assessment of antibiotic susceptibility.