Among many other virulence determinants, ICEs may spread antibiotic and metal ion resistance genes across prokaryotic phyla.
[1][3][4][5][6] In addition, ICE elements may also facilitate the mobilisation of other DNA modules such as genomic islands.
[3][7] Although ICEs exhibit various mechanisms promoting their integration, transfer and regulation, they share many common characteristics.
Some immobile genomic pathogenicity islands are also believed to be defective ICEs that have lost their ability to conjugate.
The transfer of an integrated ICE element from the donor to recipient bacterium must be preceded by its excision from the chromosome that is co-promoted by small DNA-binding proteins, the so-called recombination directionality factors.