Anti-virulence properties of catechin-in-cyclodextrin-in-phospholipid liposome through down-regulation of gene expression in MRSA strains

Methicillin resistant Staphylococcus aureus (MRSA) is a prime pathogen responsible for various infections in human beings. Expression of virulence factors is a biggest challenge in MRSA, which results in failure of conventional antibiotic therapy. In connection to the search for natural and safe anti-virulence compounds, the present study focused to evaluate the anti-virulence potential of catechin-in-cyclodextrin-in-phospholipid liposome (CCPL) on MRSA strains. CCPL inhibited young biofilm (64.15-72.70%) as well degraded mature biofilm (55.60-63.65%) at 1/2 and 1/4 MIC doses, which was further confirmed by scanning electron microscopy and confocal laser scanning microscope studies. CCPL was capable enough to modify the surface hydrophobicity (40.26-48.59%), reduce the EPS production (1.71-2.25 folds) and bacterial motility. In addition, CCPL inhibited the synthesis of virulence factors like slime production (0.40-0.50 folds), DNase production, hemolytic activity (28.08-49.07%), proteolytic production (14.65-18.04%), lipase production, autolysis and cell auto-aggregation. CCPL prevented the staphyloxanthin production and thereby increased the susceptibility of MRSA strains towards H2O2. Further, CCPL significantly down-regulated the virulence genes (agrA, agrC, clfA, clfB, fnbA, fnbB, icaA, icaD, hla, hld, rna III, atlA, sarA, sigB & geh). Thus, the results of present study revealed that the CCPL can effectively reduce the virulence properties and its application could inhibit the pathogenicity and also prevents the development of drug-resistance in MRSA strains.

Automated summary

This study evaluated the anti-virulence potential of catechin-in-cyclodextrin-in-phospholipid liposome (CCPL) on MRSA strains. The results showed that CCPL inhibited biofilm formation, modified bacterial surface characteristics, reduced toxin synthesis, and down-regulated virulence-related genes. Therefore, CCPL could be a promising approach to inhibit MRSA infections and prevent the development of drug resistance.