A New Approach to Exopolysaccharides of Post Probiotic L1 Strain: Anti-quarum Sensing Activity.

BACKGROUND

Multi-antibiotic resistance, which has increased in recent years, poses a serious societal threat as it makes the fight against deadly infection-causing pathogens even more complex and difficult. As such, the search for naturally resistant probiotic microorganisms and metabolic products obtained from these organisms to prevent infections, as an alternative to antibiotics, is crucial. In this context, preventing the quorum sensing (QS) mechanism that provides communication among bacteria is considered a mechanism that can prevent the colonization and progression of deadly infections.

AIMS

To determine the QS mechanism and the immunological effects and various biological and biochemical characterizations of exopolysaccharide (EPS) obtained from the L1 strain isolated from the vaginal microflora of healthy women.

STUDY DESIGN

Experimental laboratory study.

METHODS

The antibacterial ability, the antibiofilm and QS forming activities, and interferon (IFN)-γ and interleukin (IL)-10 production capacities of EPS were determined. The total antioxidant capacity (TAC), the surface morphology of EPS by scanning electron microscopy (SEM), the presence of functional groups, and the monosaccharide composition were determined by gas chromatographymass spectrometry (GC-MS).

RESULTS

L1-EPS demonstrated a strong antibiofilm activity on (65.14%), (63.27%), and (54.21%) at a concentration of 5.0 mg/ml. The anti-QS activity of EPS was found to be quite high at 10 mg/ml EPS concentration. In the study performed with human peripheral blood mononuclear cells (hPBMC), the immunostimulatory IFN-γ value was higher (45 ± 0.0.3) than that in the experimental group, while the IL-10 value was lower than that in the control group (36 ± 0.05). The TAC value of L1- EPS was found to be 76 μg/ml at 1,000 μg concentration. According to the GC-MS analysis results, glucose constituted 13.80% of the monosaccharide composition of EPS, while alpha-D-galactose constituted 13.89%.

CONCLUSION

Interestingly, EPSs of L1 strain, which have not been reported previously, demonstrated high anti-QS and antibiofilm properties, making EPSs a prospective compound for application in the pharmaceutical and food industries owing to their strong antimicrobial and antioxidant capacities.