Antibacterial Activity of Lactobacillus plantarum Supernatant on Non-Fermenting Gram-Negative Bacteria

Antimicrobial Effect of Lactobacillus Supernatant on Polyresistant Bacteria of the ESKAPE Group

Lactobacillus supernatants exhibit pronounced antimicrobial activity against a number of bacteria of bacteria of the ESKAPE group. The antimicrobial activity of the supernatant was evaluated using the broth microdilution assay on polystyrene plates. The highest level of inhibition (more than 10 times compared with the control) was observed against gram-positive S. aureus. Among gram-negative bacteria, the maximum level of inhibition (9.4 times compared with the control) was noted for P. aeruginosa and slightly lower in A. baumannii and K. pneumoniae. The supernatants also inhibited biofilm formation by both gram-positive and gram-negative bacteria.

The Inhibitory Activity of Lactobacillus plantarum Supernatant against Enterobacteria, Campylobacter, and Tumor Cells

Cell-free supernatant of Lactobacillus plantarum exhibit a strong antimicrobial effect against a number of pathogenic enterobacteria (E. coli, Shigella flexneri, Salmonella typhimurium, Proteus mirabilis, and Campylobacter jejuni). The degree of growth inhibition in broth culture reached a high level for all tested bacteria. The highest rates were noted for P. mirabilis (by 13 times) and the lowest for S. flexneri (by 5 times) and C. jejuni (by 4.5 times). Significant antiproliferative effect of the supernatant on cells of tumor-derived epithelial cell lines was shown. The highest degree of inhibition (by 22 times) was observed for HT-29 cells (colon carcinoma). Thus, inclusion of probiotics in traditional treatment schemes can increase the effectiveness of antibacterial and antitumor drug therapy.