[3] Although the general makeup of pathogenicity islands (PAIs) might vary throughout bacterial pathogen strains, all PAIs are known to have characteristics with all genomic islands, which includes virulence genes, functional mobility elements, and areas of homology to tRNA genes and direct repeats.
The spread of antibiotic resistance and, more generally, the conversion of non-pathogenic strains in natural environments to strains that infect animal and plant hosts with disease are two examples of the evolutionary and ecological changes brought about by the transmission and acquisition of PAIs among bacterial species.
[2] The most basic kind of mobile genetic element is an insertion sequence (IS), which usually just has one or two open reading frames that encode genes to make transposition easier.
The majority are surrounded by brief terminal inverted repeats that serve as homologous recombination sites, enhancing a PAI's stability.
[5] The bacterial membranes contain the type III secretion system (T3SS), which functions essentially as a molecular syringe.
[2] This may be due to the structure of PAIs, with direct repeats, insertion sequences and association with tRNA that enables deletion and mobilization at higher frequencies.
[3] Additionally, deletions of pathogenicity islands inserted in the genome can result in disrupting tRNA and subsequently affect the metabolism of the cell.