Abstract Introduction and objective Even the most resistant bacteria are rarely resistant to all antibiotics, leaving potential treatment options. However, existing antibiotic susceptibility tests (AST) often fail to identify them.AtbFinder is a next-generation, phenotypic but culture-independent diagnostic test designed to guide antibiotic selection for hard-to-treat respiratory infections caused by multidrug-resistant (MDR) bacteria, including VAP, COPD, CF.The AtbFinder test-kit consists of four 48-well plates, each containing a novel agar supplemented with one or more antibiotics, and antibiotic-free control wells. Antibiotics are added to the agar at concentration achievable in the lungs allowing AtbFinder to select drugs based on site-specific efficacy rather than plasma-based MIC-breakpoints used in standard AST methodsClinical samples (sputum/BAL) are plated to the agar, and for each patient , the AtbFinder tests up to 184 antibiotics within 4-8 hours.AtbFinder is the first test to select antibiotics based on (1) the response of the entire polymicrobial biofilm from the site of infection to (2) antibiotics at lung-achievable concentrations. Materials and Methods Prospective, nonrandomized, open-label study utilizing AtbFinder to formulate an individualized antibiotic regimen in ICU patients with VAP caused by MDR ESKAPE-pathogens. Outcomes were compared with control patients from the same hospitals, in whom antibiotics were selected using standard AST methods (Vitek-2,MALDI-TOF,disk-diffusion, or microbroth-dilution). Results AtbFinder group: 20 patients; Control group: 40. The 30 day mortality rate among patients treated with antibiotics selected with the AtbFinder was 0%, compared with 26% from the control group. The 30-day mortality rate among patients treated with AtbFinder-selected antibiotics was 0%, compared with 26% in the control group. The mean time to eradication of Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter spp., MRSA, VRSA, and Acinetobacter was 12.6 days, with 100% eradication in all patients. In contrast, only 46% of control patients achieved eradication, with an average of 24.2 days (p 0.01). The number of ICU and ventilator days was reduced by 60% and 78%, respectively. The relative reduction in 90-day readmission was 75%, and the total number of broad-spectrum antibiotic courses decreased by 62% in the AtbFinder group compared with controls. There were no significant differences in the outcomes among control patients treated with antibiotics selected using different AST methods. Conclusion AtbFinder addresses a critical clinical question: Can the antibiotic concentrations actually achieved in the lungs eliminate bacterial biofilms? This approach demonstrated clear superiority over standard AST methods, enabling more effective, targeted, and rapid antibiotic selection for MDR respiratory infections. This abstract is funded by: None
Tetz et al. (Fri,) studied this question.