Understanding the shared bacterial genome

Abstract

The shared bacterial gene pool is most fluid in Gram-negative bacteria, probably because their principle adaptations are to polymicrobial ecosystems in which intercommunication and the ability to rapidly acquire genetic material are great assets. Accordingly, responses to specific antimicrobial exposure in mammalian hosts over the last several decades include the sharing of genes encoding protective enzymes and other mechanisms. These provide an excellent model of adaptive behavior. Here, we discuss the ways in which common elements form mosaic structures in the shared bacterial genome, using antibiotic resistance genes in multiresistance regions and in gene-capture and mobilization systems in Gram-negative bacteria as illustrations. © 2010 Springer-Verlag New York.