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.
Highlights
Xanthan gum is a natural anionic extracellular polysaccharide
There are two major issues associated with the discovery or development of antibacterials; the first is to find or make new chemotherapeutic antimicrobials with novel modes of action, and the second is to minimize the risk of development of antimicrobial resistance (AMR) against the discovered antimicrobials
It is envisaged that by targeting quorum sensing (QS)-regulated virulence, the likelihood of development of resistance is less, as no pressure is exerted on the growth of these pathogenic bacteria
Summary
Xanthan gum is a natural anionic extracellular polysaccharide. The non-toxic and biocompatible nature of this polymer makes it quite useful for the food sector [1]. There are two major issues associated with the discovery or development of antibacterials; the first is to find or make new chemotherapeutic antimicrobials with novel modes of action, and the second is to minimize the risk of development of AMR against the discovered antimicrobials. This has led the researchers to focus on the development of alternative anti-infective strategies to combat AMR. The effect on biofilm formation, preformed biofilm and factors such as EPS production, swarming motility, and cell surface hydrophobicity that contribute to the development of biofilm against both the bacteria was studied This is probably the first study assessing the quorum sensing and biofilm inhibitory potential of green synthesized polysaccharide-zinc oxide nanocomposite
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
