Anti‐biofilm and anti‐virulence effects of silica oxide nanoparticle–conjugation of lectin purified from Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa lectin is purified and nanoparticle‐conjugated in an attempt to inhibit biofilm formation. Thirteen (23.6%) P. aeruginosa isolates are obtained from chicken meat samples, of which 30.8% are biofilm producers and 69.2% are lectin producers. Lectin is purified 36.8‐fold to final specific activity of 506.9 U/mg. Four nanoparticle types are prepared via laser ablation: platinum (Pt), gold (Au), silica oxide (SiO2), and tin oxide (SnO2). The four types are characterised, and pulse feeding is used to conjugate the lectin and nanoparticles. Pt, Au, SiO2, and SnO2 nanoparticles inhibit biofilm formation, especially SiO2 nanoparticles, which have higher effectiveness when conjugated with purified lectin. SiO2 ‐conjugated lectin significantly (p < 0.05) inhibits biofilm formation more effectively than control and other nanoparticle‐conjugated lectins. Au‐, Pt nanoparticle‐, and SnO2 ‐conjugated lectins inhibit biofilm significantly compared with control (p < 0.05), and rhlR gene expression is decreased in the presence of SiO2 ‐conjugated lectin. Furthermore, lectin and Pt, Au, SiO2 and SnO2 nanoparticles separately, and their conjugated lectins, are effective biofilm inhibitors. Of these, SiO2‐conjugated lectin was most significant as an anti‐biofilm. Moreover, virulence factors regulon and RhlR were reduced by SiO2‐ conjugated lectin, indicating that this conjugation may also decrease the virulence of P. aeruginosa.