. 2009 Oct;22(4):582–610. doi: 10.1128/CMR.00040-09

TABLE 3.

Characteristics of RND efflux pumps in P. aeruginosa

Operon	Component	Function^a	Regulator^e		Substrate(s)
Operon	Component	Function^a	Primary^b	Secondary^c	Antibiotics	Additional compounds
mexAB-oprM	MexA	MFP	MexR	NalC	Fluoroquinolones, β-lactams, β-lactamase inhibitors, tetracyclines, chloramphenicol, macrolides, novobiocin, trimethoprim, sulfonamides	Biocides (e.g., triclosan), detergents, dyes, HSL,^f aromatic hydrocarbons
	MexB	RND	NalD
	OprM	OMF
mexCD-oprJ	MexC	MFP	NfxB		Fluoroquinolones, β-lactams, tetracycline, chloramphenicol, macrolides, trimethoprim, novobiocin	Biocides (e.g., triclosan), detergents, dyes, aromatic hydrocarbons
	MexD	RND
	OprJ	OMF
mexEF-oprN	MexE	MFP	MexT	MexS	Fluoroquinolones, chloramphenicol, trimethoprim	Biocides (e.g., triclosan), aromatic hydrocarbons
	MexF	RND		MvaT
	OprN	OMF
mexXY	MexX	MFP	MexZ		Fluoroquinolones, β-lactams, tetracycline, aminoglycosides, macrolides, chloramphenicol
	MexY	RND
	OprM/Opm-^d	OMF
mexJK	MexJ	MFP	MexL		Tetracycline, erythromycin	Biocides (e.g., triclosan)
	MexK	RND
	OprM/OpmH	OMF
mexGHI-opmD	MexG	?	SoxR		Fluoroquinolones	Vanadium
	MexH	MFP
	MexI	RND
	OpmD	OMF
mexVW	MexV	MFP	—		Fluoroquinolones, tetracycline, chloramphenicol, erythromycin
	MexW	RND
	OprM	OMF
mexPQ-opmE	MexP	MFP	—		Fluoroquinolones, tetracycline, chloramphenicol, macrolides
	MexQ	RND
	OpmE	OMF
mexMN	MexM	MFP	—		Chloramphenicol, thiamphenicol
	MexN	RND
	OprM	OMF
triABC	TriA	MFP	—			Triclosan
	TriB	MFP
	TriC	RND
	OpmH	OMF

MFP, membrane fusion protein; RND, resistance-nodulation-division transporter; OMF, outer membrane factor; ?, encodes a protein of unknown function.

Regulatory proteins that directly control expression of the efflux operons.

Proteins that indirectly activate operon expression when mutated.

MexXY may utilize OpmB, OpmG, OpmH, and/or OmpI as OMFs.

—, not identified.

HSL, homoserine lactones.