The anti-biofilm effects of Lactobacillus plantarum and Lactobacillus reuteri cell-free supernatant on Pseudomonas aeruginosa and Staphylococcus aureus

BACKGROUND AND OBJECTIVESStaphylococcus aureus and Pseudomonas aeruginosa are important infectious agents in humans worldwide. They are associated with antibiotic resistance, adhesion to surfaces, biofilm formation on medical instruments, and the development of chronic opportunistic infections. These factors pose significant challenges in medicine, necessitating the search for alternative therapeutic agents. One of these solutions is direct use of natural antimicrobial producers, such as probiotics. This study aimed to describe the inhibitory activity of lyophilized cell-free supernatants (CFS) of Lactobacillus plantarum PTCC ۱۷۴۵ and Lactobacillus reuteri PTCC۱۶۵۵ against P. aeruginosa and S. aureus. One potential solution is the use of natural antimicrobial producers, such as probiotics. This study aimed to investigate the inhibitory activity of lyophilized cell-free supernatants (CFS) of Lactobacillus plantarum PTCC ۱۷۴۵ and Lactobacillus reuteri PTCC۱۶۵۵ against P. aeruginosa and S. aureus.MATERIALS AND METHODSAntibacterial activities of the CFS of lactobacilli were assessed by agar well diffusion and microtiter plate method to obtain MIC and MBC. The characteristics of the antibiofilm were analyzed by crystal violet assay. Metabolites in CFS were identified using GC-mass spectrometry-based analysis.RESULTS AND DISCUSSIONThe results showed that sub-MIC concentrations of cell-free supernatants of L. plantarum and L. reuteri significantly inhibited biofilm formation. The highest percentage of destruction of ۲۴ h-old biofilms after treatment with ۵MBC dose were obtained. The results were confirmed by scanning electron microscopy (SEM). It should be noted that supernatants neutralized with NaOH did not show any antibacterial activity.CONCLUSIONAccording to the results obtained in this research, CFS of L. plantarum and L. reuteri have promising antimicrobial and anti-biofilm activity to inhibit and destroy the biofilm of pathogenic strains.

کلیدواژه ها:

Biofilm ، Cell Free Supernatant (CFS) ، Antibiofilm ، L. Plantarum ، L. Reuteri ، P. Aeruginosa ، S. Aureus