Nanoparticles as Antimicrobial Agents against Medically Important Pathogens

Nanotechnology is gaining tremendous impetus in the present century due to its capability of modulating metals into their nano size, which drastically changes the chemical, physical and optical properties of metals. The extremely small size of nanoparticles help them to occupy a greater surface area and hence a better accessibility and targeted action. Nanoparticles can overcome existing drug resistance mechanisms, including decreased uptake and increased efflux of drug from the microbial cell, biofilm formation, and intracellular bacteria. Nanoparticles can target antimicrobial agents to the site of infection, so that higher doses of drug are given at the infected site, thereby overcoming resistance. Antibacterial nanoparticles are also very important in the textile industry, water disinfection, medicine, and food packaging. Organic compounds which are used for disinfection have some disadvantages, including toxicity to the human body; therefore, the interest in inorganic disinfectants such as metal oxide nanoparticles (NPs) is increasing. Present review focuses the wide application of different antimicrobial nanoparticles against various pathogens infecting plants and animals as well. Chitosan based nanoparticles are effective against broad range of gram positive and gram negative bacteria, which can be applied for medical applications due to less toxicity caused. Various carbon based nanoparticles like carbon nanotubes, fullerene and graphene oxide nanoparticles are toxic against the pathogens like Escherichia coli, Staphylococcus aureus, Candida albicans and Bulkholderia cepecia and various others which are animal and plant pathogens. Metal oxide nanoparticles like Al2O3, Fe3O4, CeO4, ZnO, MgO, TiO2 etc. are very useful against Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella sp. and Streptococcus sp. which are medicinally important pathogens. Besides this other nanoparticles like gold nanoparticles, copper nanoparticles and silver nanoparticles are also gaining their attention due to wide host range and targeted action.