Suppression of bacterial cell-cell signalling, biofilm formation and type III secretion system by citrus flavonoids. Academic Article uri icon

abstract

  • AIM: This study investigated the quorum sensing, biofilm and type three secretion system (TTSS) inhibitory properties of citrus flavonoids. METHODS AND RESULTS: Flavonoids were tested for their ability to inhibit quorum sensing using Vibrio harveyi reporter assay. Biofilm assays were carried out in 96-well plates. Inhibition of biofilm formation in Escherichia coli O157:H7 and V. harveyi by citrus flavonoids was measured. Furthermore, effect of naringenin on expression of V. harveyi TTSS was investigated by semi-quantitative PCR. Differential responses for different flavonoids were observed for different cell-cell signalling systems. Among the tested flavonoids, naringenin, kaempferol, quercetin and apigenin were effective antagonists of cell-cell signalling. Furthermore, these flavonoids suppressed the biofilm formation in V. harveyi and E. coli O157:H7. In addition, naringenin altered the expression of genes encoding TTSS in V. harveyi. CONCLUSION: The results of the study indicate a potential modulation of bacterial cell-cell communication, E. coli O157:H7 biofilm and V. harveyi virulence, by flavonoids especially naringenin, quercetin, sinensetin and apigenin. Among the tested flavonoids, naringenin emerged as potent and possibly a nonspecific inhibitor of autoinducer-mediated cell-cell signalling. Naringenin and other flavonoids are prominent secondary metabolites present in citrus species. Therefore, citrus, being a major source of some of these flavonoids and by virtue of widely consumed fruit, may modulate the intestinal microflora. SIGNIFICANCE AND IMPACT OF THE STUDY: Currently, a limited number of naturally occurring compounds have demonstrated their potential in inhibition of cell-cell communications; therefore, citrus flavonoids may be useful as lead compounds for the development of antipathogenic agents.

published proceedings

  • J Appl Microbiol

altmetric score

  • 3

author list (cited authors)

  • Vikram, A., Jayaprakasha, G. K., Jesudhasan, P. R., Pillai, S. D., & Patil, B. S.

citation count

  • 232

complete list of authors

  • Vikram, A||Jayaprakasha, GK||Jesudhasan, PR||Pillai, SD||Patil, BS

publication date

  • January 2010