Fabrication of Zinc Oxide-Xanthan Gum Nanocomposite via Green Route: Attenuation of Quorum Sensing Regulated Virulence Functions and Mitigation of Biofilm in Gram-Negative Bacterial Pathogens

Abstract

The unabated abuse of antibiotics has created a selection pressure that has resulted in the development of antimicrobial resistance (AMR) among pathogenic bacteria. AMR has become a global health concern in recent times and is responsible for a high number of mortalities occurring across the globe. Owing to the slow development of antibiotics, new chemotherapeutic antimicrobials with a novel mode of action is required urgently. Therefore, in the current investigation, we green synthesized a nanocomposite comprising zinc oxide nanoparticles functionalized with extracellular polysaccharide xanthan gum (ZnO@XG). Synthesized nanomaterial was characterized by structurally and morphologically using UV-visible spectroscopy, XRD, FTIR, BET, SEM and TEM. Subinhibitory concentrations of ZnO@XG were used to determine quorum sensing inhibitory activity against Gram-negative pathogens, Chromobacterium violaceum, and Serratia marcescens. ZnO@XG reduced quorum sensing (QS) regulated virulence factors such as violacein (61%), chitinase (70%) in C. violaceum and prodigiosin (71%) and protease (72%) in S. marcescens at 128 µg/mL concentration. Significant (p ≤ 0.05) inhibition of biofilm formation as well as preformed mature biofilms was also recorded along with the impaired production of EPS, swarming motility and cell surface hydrophobicity in both the test pathogens. The findings of this study clearly highlight the potency of ZnO@XG against the QS controlled virulence factors of drug-resistant pathogens that may be developed as effective inhibitors of QS and biofilms to mitigate the threat of multidrug resistance (MDR). ZnO@XG may be used alone or in combination with antimicrobial drugs against MDR bacterial pathogens. Further, it can be utilized in the food industry to counter the menace of contamination and spoilage caused by the formation of biofilms.

Biosynthesized Zinc Oxide Nanoparticles Disrupt Established Biofilms of Pathogenic Bacteria

“…The bacteria in the treated group were found to be in scattered form and mostly as a single layer of cells on the surface of glass coverslips. These results agree with previous findings, where zinc oxide-xanthan gum nanocomposites reduced the biofilms formation of C. violaceum and S. marcescens as observed under confocal microscope [37].…”

“…layer of cells on the surface of glass coverslips. These results agree with previous findings, where zinc oxide-xanthan gum nanocomposites reduced the biofilms formation of C. violaceum and S. marcescens as observed under confocal microscope [37]. The detailed examination of the changes in biofilm architecture by ZnO-NPs treatment was studied using scanning electron microscopy (SEM).…”

Effective inhibition and eradication of pathogenic biofilms by titanium dioxide nanoparticles synthesized using Carum copticum extract

“… 24 The elemental analysis of TiO 2 -NPs was performed by energy-dispersive X-ray (EDX) spectroscopy coupled to JEOL-JSM 6510 LV (Tokyo, Japan) at University Sophisticated Instrumentation Facility (USIF), AMU, Aligarh. 25 …”

Importance of Zinc Nanoparticles for the Intestinal Microbiome of Weaned Piglets

“…For example, it was observed the ZnNPs suppress biofilms formation in Chromobacterium violaceum, E. coli PAO1, Listeria monocytogenes, Streptococcus pneumoniae , and S. aureus in the dose-dependent manner ( 64 , 66 , 67 ). Green synthetized ZnO and xanthan gum nanocomposite showed inhibition effect to violacein (61%) chitinase (70%) in C. violaceum and prodigiosin (71%) and protease (72%) in S. marcescens at 128 mu g/mL concentration ( 68 ). In the term of E. coli , the ZnNPs showed efficiency as an anti-inflammatory agent and suppressed multidrug resistance producing virulence and resistance genes in E. coli isolated from chicken meat ( 69 ).…”