TABLE 2.

MICs and basal and induced ampC expression in wild-type E. cloacae ATCC 13047 and its derivative mutants

Strain	MIC (μg/ml)							Relative mRNA level of ampCa
	AMX	PTZ	FOX	CTX	CAZ	FEP	IPM	Basal	FOX inducedb	CTX inducedb
Wild-type 13047	≥256	4	≥256	0.5	1	0.03	0.5	1	21.6 ± 4.2	79.2 ± 4.5
ECLΔampC	2	4	4	0.12	0.25	0.03	0.25	≤0.01	≤0.01	≤0.01
ECLΔampR	4	4	4	0.12	0.25	0.03	0.25	1.5 ± 1.0	0.67 ± 0.1	2.9 ± 0.3
ECLΔ03254	≥256	4	≥256	0.5	1	0.03	0.5	1.1 ± 0.3	16.6 ± 3.6	60.4 ± 5.0
ECLΔ03253	≥256	4	≥256	0.5	1	0.03	0.5	1.1 ± 0.2	11.2 ± 1.6	46.3 ± 10.9
ECLΔampD	≥256	32	≥256	32	32	1	0.5	369 ± 45	707 ± 17	600 ± 106
ECLΔampE	≥256	4	≥256	0.5	1	0.03	0.5	1.2 ± 0.1	11.2 ± 1.4	145 ± 22
ECLΔampG	4	2	4	0.12	0.25	0.03	0.25	1.0 ± 0.2	1.9 ± 0.9	0.5 ± 0.2
ECLΔdacB	≥256	16	≥256	16	16	0.25	0.25	1.6 ± 0.8	7.0 ± 2.2	17.4 ± 8.5
ECLΔdacBΔampC	2	4	4	0.12	0.25	0.03	0.25	≤0.01	≤0.01	≤0.01
ECLΔampH	≥256	4	≥256	0.5	1	0.03	0.5	1.1 ± 0.7	6.0 ± 2.9	77.0 ± 18.2
ECLΔnagZ	16	2	256	0.25	0.5	0.03	0.25	1.1 ± 0.2	37.8 ± 14.1	2.1 ± 0.3

^aRelative amount of ampC mRNA compared to the wild-type 13047 basal level ± standard deviation; significant changes are indicated in bold.

^bInduction experiments carried out with 50 μg/ml of FOX or 25 μg/ml of CTX.