A Novel Strain of Probiotic Leuconostoc citreum Inhibits Infection-Causing Bacterial Pathogens

Area of Science:

• Microbiology
• Food Science
• Biotechnology

Background:

• Antimicrobial resistance necessitates novel strategies to combat infectious diseases.
• Probiotics are emerging as potential antibiotic alternatives due to their pathogen-inhibiting properties.

Purpose of the Study:

• To isolate and characterize probiotic strains with antibacterial efficiency against common pathogens.
• To evaluate the potential of identified strains as natural alternatives to antibiotics.

Main Methods:

• Isolation and identification of bacterial strains using 16S rRNA sequencing.
• In vitro assessment of probiotic characteristics, including enzyme production, carbohydrate fermentation, and gastrointestinal tract tolerance.
• Evaluation of antibacterial activity of cell-free supernatants against key pathogens (e.g., E. faecalis, E. coli, P. aeruginosa, S. aureus).
• Co-culture studies to assess competitive inhibition of pathogen growth.

Main Results:

• Two strains, identified as Leuconostoc citreum KCC-57 and KCC-58, exhibited significant probiotic traits.
• Both strains demonstrated tolerance to harsh gastrointestinal conditions and possessed auto-aggregation and hydrophobicity properties.
• Cell-free supernatants effectively inhibited the growth of tested pathogens, including Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus.
• Co-culture experiments confirmed the competitive exclusion of pathogens by L. citreum KCC-57 and KCC-58.

Conclusions:

• Leuconostoc citreum KCC-57 and KCC-58 display substantial probiotic potential and potent antibacterial activities.
• These strains represent promising candidates for development as natural antimicrobial agents, offering a viable alternative to conventional antibiotics for infectious disease control.