Phenotypic and transcriptional analysis of the antimicrobial effect of lactic acid bacteria on carbapenem-resistant Acinetobacter baumannii: Lacticaseibacillus rhamnosus CRL 2244 an alternative strategy to overcome resistance?"

Carbapenem-resistant (CRAB) is a recognized nosocomial pathogen with limited antibiotic treatment options. Lactic acid bacteria (LAB) constitute a promising therapeutic alternative. Here we studied the antibacterial properties of a collection of LAB strains using phenotypic and transcriptomic analysis against clinical strains. One strain, CRL 2244, demonstrated a potent inhibitory capacity on with a significant killing activity. Scanning electron microscopy images showed changes in the morphology of with an increased formation of outer membrane vesicles. Significant changes in the expression levels of a wide variety of genes were also observed. Interestingly, most of the modified genes were involved in a metabolic pathway known to be associated with the survival of . The operon, Hut system, and fatty acid degradation were some of the pathways that were induced. The analysis reveals the impact of CRL 2244 on response, resulting in bacterial stress and subsequent cell death. These findings highlight the antibacterial properties of CRL 2244 and its potential as an alternative or complementary strategy for treating infections. Further exploration and development of LAB as a treatment option could provide valuable alternatives for combating CRAB infections.