Recent advances in antibacterial applications of metal nanoparticles (MNPs) and metal nanocomposites (MNCs) against multidrug-resistant (MDR) bacteria

ABSTRACT

Introduction: In recent years, multidrug resistance (MDR) in bacteria has drastically increased and has posed a great threat to the human health. This problem has generated an urgent need to search alternatives for the treatment of MDR bacteria. It has been proved that metal nanoparticles (MNPs) and metal nanocomposites (MNCs) possess remarkable antimicrobial potential, and hence can be used in alternative therapy.

Areas covered: This review is aimed to discuss recent reports on antibacterial activities of MNPs and MNCs against MDR bacteria.

Expert opinion: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Serratia marcescens, Streptococcus pneumoniae, and Staphylococcus epidermidis are important pathogenic bacteria which have shown MDR against a wide range of conventional antibiotics. In this context, effects of MNPs and MNCs on these pathogens have demonstrated considerable efficacy. Several mechanisms concerning activity of MNPs and MNCs against pathogenic bacteria which are mainly dependent on type of their precursors and treated bacterium have been investigated. In addition, many studies have been made on antibacterial activities of these nanomaterials with similar and different results.

KEYWORDS:

• Multidrug resistance
• nanomaterials
• metal nanoparticles
• metal nanocomposites
• antibacterial mechanisms

Article highlights

• Annually, 100,000 tons of antibiotics are produced to treat bacterial infections. However, these antibiotics have failed to control MDR bacteria, and therefore, there is a pressing need to search for novel antibiotics or other alternatives.

• Several mechanisms can contribute to antibiotic resistance of bacteria involving a reduction in the drug uptake, modifications of the antibacterial target, activation of efflux mechanisms for extrusion of the antibacterial agents, and global alterations in prominent metabolic pathways.

• MNPs and MNCs with unique properties compared to bulk materials and conventional antibiotics can be considered as new suitable weapon against MDR bacteria.

• There are several methods for synthesis of these nanomaterials. Among these, biogenic synthesis is eco-friendly and economically viable.

• Recent studies have provided evidence that antibacterial activities of MNPs and MNCs may be resulted from several mechanisms including blistering (blebs), clumping of membranes, and blockage of electron transport chain.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosurest

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.