Canadian Journal of Infectious Diseases and Medical Microbiology

Research Article

Molecular Epidemiology of Carbapenem-Resistant Klebsiella pneumoniae in a Tertiary Hospital in Northern China

Table 4

Imipenem MICs of 45 CRKP isolates with different carbapenemases, ESBLs, and AmpC combination profiles.


Resistance profile	N (%)	No. of isolates by MIC (μg/mL)							MIC₅₀ (μg/mL)	MIC₉₀ (μg/mL)
Resistance profile	N (%)	4	8	16	32	64	128	256	MIC₅₀ (μg/mL)	MIC₉₀ (μg/mL)

Carb + ESBL + AmpC+	3 (6.7)	0	0	0	3	0	0	0	32	32
Carb + ESBL + AmpC−	42 (93.3)	17	11	4	5	3	0	2	8	64
Carbapenemase genes
KPC-2	25 (55.6)	13	7	1	2	1	0	1	4	32
KPC-2, GES	14 (31.1)	3	3	3	2	2	0	1	16	64
GES	1 (2.2)	0	0	0	1	0	0	0	32	32
NDM-1	1 (2.2)	0	0	0	1	0	0	0	32	32
KPC-2, NDM-1	1 (2.2)	1	0	0	0	0	0	0	4	4
KPC-2, NDM-1, GES	1 (2.2)	0	0	0	1	0	0	0	32	32
KPC-2, NDM-1, IMP	1 (2.2)	0	1	0	0	0	0	0	8	8
GES, NDM-1	1 (2.2)	0	0	0	1	0	0	0	32	32

ESBL, extended-spectrumβ-lactamase; Carb: carbapenemase; AmpC: AmpC-β-lactamase; MIC, the minimal inhibitory concentration; μg/ml, micrograms per milliliter; MIC₅₀, minimum inhibitory concentration for 50% of the isolates; MIC₉₀, minimum inhibitory concentration for 90% of the isolates.