A Simple Label-Free Method Reveals Bacterial Growth Dynamics and Antibiotic Action in Real-Time

Background: Understanding the response of bacteria to environmental stress is hampered by relative insensitivity methods detect growth. This means studies antibiotic resistance and other physiological often exceed 24 hours. Methods: We developed a scattered light detection system (SLIC) address this challenge, establishing LoD (LoD), time growth small inocula. compared light-scattering grown in different nutrient conditions dynamics two closely related organisms. Scattering data was modelled using Gompertz Broken Stick equations. Bacteria were also exposed meropenem, gentamicin, cefoxitin at various concentrations captured real-time.  Findings: established for SLIC be between 10-100 cfu mL-1 volume 1-2mL. Quantitative measurements effects on obtained less than four hours it possible rapidly distinguish differences of Klebsiella pneumoniae strains with without BlaKPC gene. There dose-dependent difference speed action each tested supra-MIC concentrations. The lethal effect lytic slow bactericidal demonstrated real-time. Significantly, that sensitive antibiotics could identified seconds. Interpretation: research demonstrates critical importance improving sensitivity bacterial detection. ability assess susceptibility capture wealth presented. rapid an important finding needs incorporated into pharmacokinetic pharmacodynamic models. Importantly, enhanced opens possibility results being reportable clinically few minutes. Funding Information: Scottish Enterprise, NESTA Longitude Prize, University St Andrews Declaration Interests: None declare.