Antimicrobial Peptides: Virulence and Resistance Modulation in Gram-Negative Bacteria

Abstract

Growing resistance to antibiotics is one of the biggest threats to human health. One of the possibilities to overcome this resistance is to use and develop alternative molecules such as antimicrobial peptides (AMPs). However, an increasing number of studies have shown that bacterial resistance to AMPs does exist. Since AMPs are immunity molecules, it is important to ensure that their potential therapeutic use is not harmful in the long term. Recently, several studies have focused on the adaptation of Gram-negative bacteria to subinhibitory concentrations of AMPs. Such concentrations are commonly found in vivo and in the environment. It is therefore necessary to understand how bacteria detect and respond to low concentrations of AMPs. This review focuses on recent findings regarding the impact of subinhibitory concentrations of AMPs on the modulation of virulence and resistance in Gram-negative bacteria.

Keywords: Gram-negative; antimicrobial peptide; resistance; subinhibitory concentration; virulence.

Figure 1

Impact of subinhibitory concentrations of antimicrobial peptides on resistance, virulence, and biofilm formation in Gram-negative bacteria. The double arrows illustrate the connections between virulence, resistance, and biofilm formation. Examples of Gram-negative bacteria responding to subinhibitory concentrations of antimicrobial peptides (AMPs) are provided in each section.