Editing Staphylococcus aureus (section)

==== Efflux pumps ====
Among the various mechanisms that MRSA acquires to elude antibiotic resistance (e.g., drug inactivation, target alteration, reduction of permeability) there is also the overexpression of [[efflux pump]]s. Efflux pumps are membrane-integrated proteins that are physiologically needed in the cell for the exportation of xenobiotic compounds. They are divided into six families, each of which has a different structure, function, and transport of energy. The main efflux pumps of ''S. aureus'' are the MFS ([[Major Facilitator Superfamily]]) which includes the MdeA pump as well as the NorA pump and the MATE (Multidrug and Toxin Extrusion) to which it belongs the MepA pump. For transport, these families use an electrochemical potential and an ion concentration gradient, while the ATP-binding cassette (ABC) family acquires its energy from the hydrolysis of ATP.{{citation needed|date=December 2022}}

These pumps are overexpressed by MDR ''S. aureus'' (Multidrug resistant ''S. aureus)'' and the result is an excessive expulsion of the antibiotic outside the cell, which makes its action ineffective. Efflux pumps also contribute significantly to the development of impenetrable biofilms.{{citation needed|date=December 2022}}

By directly modulating efflux pumps' activity or decreasing their expression, it may be possible to modify the resistant phenotype and restore the effectiveness of existing antibiotics.<ref>{{cite journal | vauthors = Holasová K, Křížkovská B, Hoang L, Dobiasová S, Lipov J, Macek T, Křen V, Valentová K, Ruml T, Viktorová J | title = Flavonolignans from silymarin modulate antibiotic resistance and virulence in ''Staphylococcus aureus'' | journal = Biomedicine & Pharmacotherapy | volume = 149 | pages = 112806 | date = May 2022 | pmid = 35303568 | doi = 10.1016/j.biopha.2022.112806 | doi-access = free }}</ref>