TABLE 6.

Effect of simultaneous expression of pairs of multicomponent pumps on susceptibility to antibiotics in P. aeruginosa

Strain	Genotype	Pump Status			MIC (μg/ml)
		MexAB-OprM	MexCD-OprJ	MexEF-OprN	Levofloxacin	Tetracycline	Chloramphenicol	Cefpirome	Cefepime	Carbenicillin	Aztreonam	Rifampin
PAM1020	Wild type	+	−	−	0.125	4	128	1	0.5	64	2	16
PAM1275	mexB::Hg	−	−	−	0.03	0.5	4	0.25	0.125	0.5	0.25	16
PAM1032	nalB1032	+++	−	−	1	32	512	4	4	256	16	16
PAM1277	mexB::Hg nfxB1033	−	+++	−	2	16	512	16	4	0.5	0.125	NDa
PAM1465	mexB::Hg nfxB1438	−	+++	−	1	16	256	8	2	0.5	0.125	ND
PAM1438	nalB1032 nfxB1438	+++	+++	−	2	64	512	16	4	256	16	16
PAM2359	nalB2281 ΔmexEF::Gm	+++	−	−	1	32	512	ND	ND	256	16	ND
PAM2360	nalB2282 ΔmexEF::Gm	+++	−	−	1	16	256	2	2	256	16	ND
PAM1278	mexB::Hg nfxC1034	−	−	+++	2	8	2048	0.25	0.25	0.5	0.125	ND
PAM2281	nalB2281 nfxC1034	+++	−	+++	4–8	64	2048	4	4	256	16	16
PAM2282	nalB2282 nfxC1034	+++	−	+++	4	32	2048	2	2	256	8	16
PAM2302	nalB2281 nfxC1034 nfxB2302	+++	+++	+++	8	128	>512	8	4	256	16	16
PAM2303	nalB2281 nfxC1034 nfxB2303	+++	+++	+++	4–8	64	2048	8	4	128	8	16
PAM2387	oprM::Hg nfxC1034 nfxB2303	−	+++	+++	4–8	32	2048	8	2	0.5	0.125	ND

^aND, not determined.