DefinePK

Abstract

Bacteria develop in order to adapt to new surroundings, colonize new niches, and become pathogenic. The presence of mobile genetic elements MGEs in  E. coli  can be increasing the genome size of a pathogenic strain by up to 1 Mb when compared to a commensal strain. Phage satellites make up one subset of MGEs they are linked to specific temperate phages, named as helper phages, which parasite bacteria for their own induction. In fact, various pathogenic  E. coli  differ in the presence of a subset of genes produced by MGEs that are crucial in hijacking host cell machinery and subverting host responses. Phages not only provide genetic variability through prophage integration, they can also mediate horizontal genetic transfer HGT within bacterial populations through the transfer of either bacterial DNA or other MGEs, such as phage satellites. The phage-mediated transfer of bacterial DNA is known as transduction and plays a crucial role in bacterial biology, diversity and evolution. Recently, it has been noticed that phage transduction occurs at an astonishing magnitude, much higher than previously anticipated. Importantly, some of the genes transferred by transduction are virulence and antibiotic resistance genes, highlighting the impact that this process has in driving evolution of pathogenic bacteria. Keywords:  E .  coli ; HGT; MGEs; Bacteriophages; Transduction;  virulence Genes