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Chitosan and chitosan-zinc oxide nanocomposite inhibit expression of LasI and RhlI genes and quorum sensing dependent virulence factors of Pseudomonas aeruginosa
- Badawy, Mona Shaban E.M., Riad, Omnia Karem M., Taher, F.A., Zaki, Samar A.
- International journal of biological macromolecules 2020 v.149 pp. 1109-1117
- Fourier transform infrared spectroscopy, Pseudomonas aeruginosa, X-ray diffraction, antibiotics, biofilm, chemical structure, chitosan, gene expression regulation, genes, homoserine, lactones, nanocomposites, particle size, phenotype, pyocyanin, quantitative polymerase chain reaction, quorum sensing, therapeutics, thermal stability, virulence, zinc oxide
- The great ability of Pseudomonas aeruginosa to cause chronic infection is attributed to several virulence factors, biofilm formation, intrinsic and acquired resistance to many antibiotics. Anti-quorum sensing (QS) and anti-virulence therapy are promising alternatives to the existing antibiotic therapy. In this study, the effect of chitosan and the prepared chitosan-zinc oxide (CH/ZnO) nanocomposite on QS-dependent virulence factors and acyl homoserine lactone “AHL” production was studied. The chemical structure of the prepared CH/ZnO nanocomposite was characterized by FT-IR spectrum and XRD. The thermal stability and particle size were determined. Chitosan causes a significant decrease in AHL, biofilm, pyocyanin production and motility of P. aeruginosa. CH/ZnO nanocomposite augments the inhibitory activity of chitosan in both phenotypic and genotypic levels. Both chitosan and CH/ZnO nanocomposite downregulate the expression of LasI and RhlI genes using quantitative real-time PCR. The expression of RhlI gene in PAO1 is reduced by 1240 folds after treatment with CH/ZnO nanocomposite. The expression of LasI and RhlI genes in clinical isolates is reduced by 1778.07 and 627.29 folds upon treatment with CH/ZnO. These promising results may find a rescue in the battle of fighting P. aeruginosa by repressing its QS-dependent virulence factors.