In Vivo Bacterial Tracking Technology Based on Membrane Dye Labeling

Present methodologies for assessing antimicrobial effectiveness in living systems are heavily dependent on terminal detection approaches, including colony-forming unit enumeration and histological examination after animal euthanasia, for evaluating antimicrobial characteristics. Such conventional assessment techniques fail to monitor real-time alterations in infectious conditions throughout therapeutic interventions. This investigation introduces an innovative approach employing lipophilic near-infrared fluorophores for bacterial fluorescent tagging, integrated with IVIS (in vivo imaging system) technology, to accomplish continuous surveillance of bacterial infections in targeted infection models. Subsequently to localized administration of fluorescently marked bacteria, IVIS imaging demonstrated temporal variations in fluorescent signals within infection sites, which were subsequently employed to assess the in vivo performance of antimicrobial biomaterials. This methodology has been successfully verified using a rat tibial bone defect infection model. Experimental findings indicate that this technique provides immediate visualization of antimicrobial treatment effects and enables accurate quantitative evaluation, offering a methodological foundation for in vivo antimicrobial efficacy assessment.