The arginine catabolic mobile element (ACME) is a
mobile genetic element
Mobile genetic elements (MGEs) sometimes called selfish genetic elements are a type of genetic material that can move around within a genome, or that can be transferred from one species or replicon to another. MGEs are found in all organisms. In h ...
of ''
Staphylococcus
''Staphylococcus'' is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillales. Under the microscope, they appear spherical ( cocci), and form in grape-like clusters. ''Staphylococcus'' species are facultat ...
''
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...
l species. This genetic element provides for several immune modulating functions, including resistance to polyamines which serve as a non-specific immune response both on intact skin and following the inflammatory response in wound healing. Diverse ACME are present in several species of ''Staphylococcus'', including ''
Staphylococcus epidermidis
''Staphylococcus epidermidis'' is a Gram-positive bacterium, and one of over 40 species belonging to the genus ''Staphylococcus''. It is part of the normal human microbiota, typically the skin microbiota, and less commonly the mucosal microbiot ...
''.
Association with virulent
MRSA
Methicillin-resistant ''Staphylococcus aureus'' (MRSA) is a group of Gram-positive bacteria that are genetically distinct from other strains of ''Staphylococcus aureus''. MRSA is responsible for several difficult-to-treat infections in humans. ...
ACME are not common among antibiotic sensitive ''
S. aureus'' (MSSA). The elements for the most prominent MRSA ACME appear to have assembled recently in ''S. epidermidis'' into the speG-positive ACME which was transferred to virulent ''S. aureus'' during the evolution of the epidemic USA300
MRSA
Methicillin-resistant ''Staphylococcus aureus'' (MRSA) is a group of Gram-positive bacteria that are genetically distinct from other strains of ''Staphylococcus aureus''. MRSA is responsible for several difficult-to-treat infections in humans. ...
strain. This broadened the ability of ''S. aureus'' to colonize sites other than a specific part of the nose.
This strain is able to persist on intact skin and is spread rapidly person-to-person. As a result, the speG-positive ACME is a particularly important element of MRSA pathogenesis.
See also
*
Mobile genetic elements
Mobile genetic elements (MGEs) sometimes called selfish genetic elements are a type of genetic material that can move around within a genome, or that can be transferred from one species or replicon to another. MGEs are found in all organisms. In ...
References
Molecular biology
Mobile genetic elements
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