S. aureus Evolution: Lineages and Mobile Genetic Elements (MGE)
Jodi A. Lindsay
from: Staphylococcus: Molecular Genetics (Edited by: Jodi Lindsay). Caister Academic Press, U.K. (2008)
There is enormous variation between strains of S. aureus. Evolution occurs when genomes vary and the fittest bacteria are selected. Variation occurs in three major ways: single nucleotide polymorphisms (SNP) and other minor changes in conserved core genes; variation in hundreds of genes (particularly those encoding proteins that interact with host) that are associated with lineages of S. aureus; and acquisition and loss of mobile genetic elements (MGE) which often encode virulence and resistance genes. Barriers that block horizontal transfer of DNA, such as restriction modification, influence lineages and MGE. S. aureus MGE have their own complex life-cycles that control their spread and survival. Selection of the fittest bacteria is likely being driven by mammalian host factors and antibiotic use, and new strains of S. aureus are emerging that are increasingly virulent and resistant to antibiotics, causing novel healthcare issues read more ...