The discovery of novel therapies is required due to the stark rise in microbial resistance to currently available conventional antibiotics, which poses a significant obstacle to the effective management of infectious diseases. Nanomaterials between 1 and 100 nm in size have recently become effective antibacterial agents. In particular, several classes of antimicrobial nanomaterials and nanosized carriers for antibiotic delivery have demonstrated their efficacy for treating infectious diseases, including antibiotic-resistant ones, in vitro and in animal models. Because of their high surface area-to-volume ratios, these materials can provide better therapy than conventional drugs and have new mechanical, chemical, electrical, optical, magnetic, electro-optical, and magneto-optical properties. So, nanoparticles have been proven to be fascinating in the fight against bacteria. In this chapter, we will go into detail about the various characteristics of microorganisms and how they differ across each strain. The toxicity mechanisms change depending on the stain. Even the effectiveness of nanomaterials to treat different bacteria and their defence mechanisms varies depending on strains, particularly the composition of cell walls, the makeup of the enzymes, and other factors. As a result, a perspective on nanomaterials in the microbial world, a method to combat drug resistance by tagging antibiotics in nanomaterials, as well as predictions for their future in science.