Phytochemicals against drug-resistant microbes

Abstract

Bacteria are able to adapt to undesirable changes in nutrient availability, environmental conditions and presence of antimicrobial products, as well as to immunological defenses. Antibiotic resistant bacteria are increasingly prevalent and consequently new antimicrobials are needed to control these pathogens. Serious infections caused by bacteria that have become resistant to commonly used antibiotics have become a major global healthcare problem in the twenty-first century. Development of resistance, including multidrug resistance (MDR), is unavoidable because it represents a particular aspect of the general microbial evolution. Many bacterial diseases, which were thought to have been eradicated from developing countries, might once again become a serious health problem. There is thus an urgent need for products that act on novel molecular targets that circumvent resistance mechanisms. In this context, plant secondary metabolites (phytochemicals) have already demonstrated their potential as antibacterials when used alone, and as synergists/potentiators of less effective products. Moreover, phytochemicals can be used where bacterial resistance mechanisms, such as MDR, make conventional treatments ineffective and also in the control of biofilms. The aim of this chapter is to cover the recent advances on phytochemical antibacterial activities against drug-resistant bacteria.