TABLE 2.

Susceptibilities of E. cloacae 8009 and various transformants to β-lactams

Strain	Presence of ampR	MIC (μg/ml)
		Cefuroxime	Cefotaxime	Ceftizoxime	Cefoperazone	Ceftazidime	Cefoselis	Cefoxitin	Moxalactam	Aztreonam	Imipenem
E. cloacae 8009	+	>100	100	6.25	>100	3.13	12.5	>100	0.78	12.5	0.78
E. coli DH10B	−	6.25	0.05	≦0.025	0.1	0.2	≦0.025	3.13	0.1	0.1	0.2
E. coli DH10B/pFCX310	−	>100	50	1.56	50	3.13	3.13	3.13	0.2	25	0.39
E. coli DH10B/pFCX320	−	>100	50	1.56	100	3.13	6.25	3.13	0.2	25	0.2
E. coli DH10B/pFCX300L	+	50	0.78	0.05	0.78	0.2	0.1	3.13	0.1	0.78	0.2
E. coli DH10B/pFCX300M	+	>100	6.25	0.2	6.25	1.56	0.78	6.25	0.2	6.25	0.39
E. coli DH10B/pFCX301	+	>100	25	0.78	25	3.13	3.13	6.25	0.39	25	0.2
E. coli DH10B/pFCX302	+	>100	25	1.56	50	3.13	3.13	6.25	0.39	25	0.2
E. cloacae 199Sa		3.13	0.05	≦0.025	0.2	0.1	≦0.025	0.78	0.05	≦0.025	0.05
E. cloacae 199S/pFCX310		>100	25	0.39	50	1.56	1.56	0.78	0.05	6.25	0.05
E. cloacae 199S/pFCX320		>100	50	1.56	>100	3.13	6.25	1.56	0.1	12.5	0.05
E. cloacae 199b		6.25	0.2	0.1	0.39	0.2	0.05	>100	0.1	0.1	0.39
E. cloacae 199Cc		>100	50	50	25	50	1.56	>100	3.13	25	0.2
E. coli DH5α	−	3.13	≦0.025	≦0.025	≦0.025	0.05	≦0.025	3.13	0.1	≦0.025	0.2
E. coli DH5α/FEC-1	−	>100	>100	6.25	>100	12.5	100	3.13	0.39	50	0.2
E. coli KU3290d	+	>100	25	50	50	100	1.56	>100	12.5	25	0.2

^aβ-Lactamase nonproducer. 

^bInducible β-lactamase producer (original strain). 

^cConstitutive β-lactamase producer. 

^dTransformant producing cloned P. vulgaris β-lactamase.