Antagonistic Activity of Newly Isolated Lactobacillus Strains Against Morganella Morganii

Morganella morganii is an important clinical pathogen with fast-paced multidrug resistance and virulence. Probiotics with potent antimicrobial activity are considered as a promising alternative to antibiotics in infection treatment. We isolated 12 lactobacilli strains of human and plant origin and characterized their beneficial properties focusing on their antagonistic activity against M. morganii. Tolerance to the hostile gastrointestinal environment, surface properties (hydrophobicity and autoaggregation), and acidification rate values varied considerably between strains and were strain-specific. Most Lactobacillus strains showed antibiotic resistance profiles typical for lactobacilli. Lactobacilli demonstrated inhibitory activity towards the growth of M. morganii in the agar-overlay assay, produced bacteriocins and coaggregated with M. morganii cells, but did not affect the growth of the pathogen during co-culturing in the mixed-species biofilms. Lactiplantibacillus plantarum strain FCa3L was selected as the candidate strain with potential probiotic properties for further investigation.