Epidemic of Klebsiella pneumoniae ST11 Clone Coproducing KPC-2 and 16S rRNA Methylase RmtB in a Chinese University Hospital

Table 2 Susceptibility profiles of 48 RPKP and 36 RNKP isolates

Antimicrobial agents	MIC range, μg/mL		MIC _50, μg/mL		MIC _90, μg/mL		Susceptible percentage,%			P-value
Antimicrobial agents	RNKP(n = 48)	RPKP(n = 36)	RNKP	RPKP	RNKP	RPKP	all isolates	RNKP	RPKP	P-value
Imipenem	4-256	8-128	128	128	256	128	0	0	0	—
Meropenem	2-256	4-128	64	64	128	64	0	0	0	—
Ertapenem	4-512	8-512	128	128	256	128	0	0	0	—
Cefotaxime	16 to >512	16 to >512	256	>512	512	>512	0	0	0	—
Cefepime	4-256	4-512	128	128	128	512	11.1	11.1	11.1	>0.99
Gentamicin	1 < to >512	256 to >512	8	>512	128	>512	21	47.2	0	<0.01
Netilmicin	1 to >512	256 to >512	8	>512	256	>512	32.1	72.2	0	<0.01
Amikacin	2 to >512	256 to >512	4	>512	>512	>512	39.5	88.9	0	<0.01
Tetracycline	4 to >512	8-256	16	32	512	128	3.7	8.3	0	0.084
Minocycline	2-128	4-32	4	8	64	32	27.2	52.8	6.7	<0.01
Ciprofloxacin	0.25 < to 64	2-64	64	64	64	64	6	13.9	0	0.015
Ofloxacin	0.25 < to 64	1-64	64	64	64	64	8.4	13.9	4.3	0.23
Tigecycline	0.5-4	0.5-4	2	2	2	2	96.3	97.2	95.6	>0.99
Colistin	0.25-256	0.5-2	1	1	2	2	98.8	97.2	100	0.44
Fosfomycin	1 to >1024	2 to > 1024	16	>1024	64	>1024	43.4	88.9	8.5	<0.01

Footnotes. RPKP, rmtB-positive KPC-producing K. pneumoniae; RNKP, rmtB-negative KPC-producing K. pneumoniae; MIC, minimum inhibitory concentration; MIC₅₀, MIC required to inhibit the growth of 50% of organisms; MIC₉₀, MIC required to inhibit the growth of 90% of organisms.