Multiple Pathways of Genome Plasticity Leading to Development of Antibiotic Resistance

Abstract

The emergence of multi-resistant bacterial strains is a major source of concern and has been correlated with the widespread use of antibiotics. The origins of resistance are intensively studied and many mechanisms involved in resistance have been identified, such as exogenous gene acquisition by horizontal gene transfer (HGT), mutations in the targeted functions, and more recently, antibiotic tolerance through persistence. In this review, we focus on factors leading to integron rearrangements and gene capture facilitating antibiotic resistance acquisition, maintenance and spread. The role of stress responses, such as the SOS response, is discussed.

Keywords: CRP; RpoS; SOS; horizontal gene transfer; integron; reactive oxygen species; sub-MIC.

Figure 1

Model of intIA regulation and its implications for genome plasticity. Grey boxes represent mechanisms involved in IntIA regulation. Horizontal gene transfer (conjugation, transformation) induces SOS through ssDNA uptake by recipient cells, which in turn triggers intIA transcription. Carbon sources present in the environment also regulate IntIA expression through carbon catabolite control (adapted from [31], Copyright© American Society for Microbiology).