Table 1.

Clinical and microbiological characteristics of four pairs of isolates with conversion of carbapenem susceptibility.

Age (year)/sex	Patient 1		Patient 2		Patient 3		Patient 4
	61/M		63/M		96/M		52/M
Strain	K. pneumoniae 1-S	K. pneumoniae 1-R	K. pneumoniae 2-S	K. pneumoniae 2-R	M. morganii-S	M. morganii-R	E. aerogenes-S	E. aerogenes-R
Time from hospitalization to bacterial isolation (d)	6	29	224	231	36	129	5	17
Antibiotics use before bacterial isolationa	CXM	CXM; CED	CAZ; AK; SCF	CAZ; LEV	/	MEM	/	TGC; SCF
Source	Urine	Urine	Sputum	Sputum	Sputum	Sputum	Sputum	Sputum
STb	11	11	11	11	NA	NA	NA	NA
Minimum inhibitory concentrations (μg/ml)
Imipenem	0.25	8	0.125	32	1	2	0.5	16
Meropenem	0.5	16	0.25	32	≤ 0.06	0.25	≤ 0.06	16
Piperacillin/tazobactam	>128	>128	>128	>128	0.25	16	8	128
Ceftazidime	16	32	128	128	8	16	8	64
Amikacin	>128	>128	>128	>128	1	1	>128	>128
Levofloxacin	128	64	128	128	4	4	2	4
Polymyxin B	1	1	1	1	1	1	1	1
Tigecycline	1	1	2	2	2	2	2	2

^aCXM, cefuroxime; CED, cefradine; CAZ, ceftazidime; AK, amikacin; SCF, cefoperazone-sulbactam; MEM, meropenem; TGC, tigecycline; LEV, levofloxacin.

^bNA, not applicable.