Plant Essential Oils as Potent Antimicrobials

Antimicrobial resistance (AMR) is spreading at an alarming rate, reducing the effectiveness of antibiotics and producing undesirable results such as increased mortality and significant economic loss. Public health is seriously threatened by this global problem, which restricts our capacity to treat common infections and increases risk for vulnerable groups. To address this expanding issue, a novel and effective antimicrobial agent or treatment strategy is needed. Essential oils represent an important source of a diverse range of bioactive constituents with potent antimicrobial activity. Wider acceptance due to its traditional use, lower toxicity, and ability to target multiple determinants of resistance makes essential oils a potent candidate for effectively tackling AMR and eradicating drug-resistant pathogens. Essential oil-loaded nanomaterials have also shown improved efficacy in treating antimicrobial resistance due to increased bioavailability, stability, and solubility and reduced degradation of the active principles of essential oils. Furthermore, combining essential oils with antibiotics has a synergistic impact, helping to revitalize an otherwise depleted antibiotic arsenal. This chapter gives a comprehensive summary of the antibacterial properties of essential oils and their active principles. The chapter also highlights the major bacterial AMR-determinants targeted by plant essential oils besides discussing the successful experiments on the combination of essential oils with antibiotics and nanomaterials for combating drug-resistant microbes.