Quorum Sensing as target for antimicrobial chemotherapy

Abstract

The increasing antibiotic resistance of human pathogens and their tolerance mechanisms to antimicrobial agents highlight the need for new therapeutic strategies. The phenomenon of quorum sensing (QS) is mediated by small signaling molecules, and plays major roles in bacterial physiology and ecology. Since its discovery more than 40 years ago, QS has been shown in many microorganisms, including animal and plant pathogens, and extensive studies have revealed that, among other physiological properties, virulence is often controlled by QS mechanisms. These findings prompt a move for novel ways to control microbial populations, changing the focus from traditional bacteriostatic or bacteriolytic agents to new compounds targeting QS systems. Consequently, natural and synthetic QS-Interfering compounds (QSIs) that neither destroy nor inhibit the growth of pathogens, but modulate microbial phenotypes by attenuating virulence, are now being characterized. QSI agents can be potentially utilized to reduce the spread of infection or to improve the removal of pathogens. Moreover, the pharmacological targeting of nonessential functions, such as virulence factors or biofilm formation, may alleviate the development of resistance by lessening the need of using conventional agents which, by themselves, select for resistance. The usefulness of these kinds of compounds against infection does not just rely on being a therapy but also in representing a prophylactic approach to avoid invasion of materials where infection can initiate. Some relevant developments on these topics are discussed.