TABLE 2.

Alteration in the permeability rate of imipenem and penems through the outer membrane of P. aeruginosa PAO1 and its mutants by transformation with pKMF014, pKMF016^a

Strain/plasmid	Phenotypeb		Permeability ratec (%) of:
	MexAB	OmpF	Imipenem	Faropenem	Sulopenem
PAO1/pKMF016	+	−	4.98 ± 0.64	1.43 ± 0.40	0.48 ± 0.06
PAO1/pKMF014	+	+	14.46 ± 2.17	2.58 ± 0.43	2.47 ± 0.39
KG2225/pKMF016	−	−	4.26 ± 0.40	1.50 ± 0.32	0.58 ± 0.10
KG2225/pKMF014	−	+	15.02 ± 1.45	2.52 ± 0.17	2.45 ± 0.02
OCR1/pKMF016	++	−	4.50 ± 0.64	1.54 ± 0.35	0.55 ± 0.08
OCR1/pKMF014	++	+	16.38 ± 2.17	2.56 ± 0.31	2.42 ± 0.14

^aAs described in Results, for the permeability test, P. aeruginosa cells carrying the respective plasmids grown to exponential phase were further incubated for 2 h in L broth containing 1 mM IPTG. 

^b+, wild-type level; −, nonexpression; ++, overexpression. 

^cThe results are presented as the mean ± standard deviation of three experiments.