Bacterial Sex, Superbugs & Drugs
Horizontal gene transfer (HGT) is an essential feature in the evolution of bacteria. One mechanism by which HGT can be achieved is bacterial conjugation (bacterial sex). Bacterial conjugation is cell-cell contact dependent transfer of single stranded DNA through a cell-envelope localized type IV secretion system (T4SS). Genes for this type of HGT reside on conjugative plasmids (CPs) or integrated conjugative elements (ICEs). Bacterial conjugation is ubiquitous in the bacterial and archaebacterial world and facilitates efficient gene transfer within populations of the same species and across species boundaries. It is responsible for rapid spread and persistence of virulence and antibiotic resistance genes in pathogenic bacteria (superbugs) causing increasing problems in treatment of diseases using antibiotics (drugs).