Investigation of in vitro susceptibility and resistance mechanisms to amikacin among diverse carbapenemase-producing Enterobacteriaceae

Table 3 Susceptibility of strains carrying different β-lactamase genes to clinical commonly used antibiotics and amikacin (%)

Antibacterial agents	CRE(n = 72)		bla_KPC (n = 24)	bla_NDM (n = 20)	bla_{OXA−48−like} (n = 23)	bla_KPC+NDM (n = 5)
Antibacterial agents	MIC range	R%	R%	R%	R%	R%
Cefoperazone-sulbactam	32 ->128	91.7	95.8	93.1	100	100
Piperacillin-tazobactam	> 256	100	100	100	100	100
Ceftazidime-avibactam	0.5->32	27.8	0	100	0	100
Ceftazidime	2->32	98.6	95.8	100	100	100
Ceftriaxone	2->32	97.2	91.7	100	100	100
Cefepime	2->32	95.8	87.5	100	100	100
Aztreonam	2->128	94.4	95.8	90	100	80
Ertapenem	8->32	100	100	100	100	100
Imipenem	2->16	95.8	100	100	91.3	80
Meropenem	4->16	100	100	100	100	100
Amikacin	0.5–1024	41.7	20.8^*	5^*	100^*	20^*
Gentamycin	1->128	77.8	87.5	45	100	60
Ciprofloxacin	0.5->8	95.8	100	85	100	100
Levofloxacin	0.5->16	88.9	83.3	80	100	100
Trimethoprim-sulfamethoxazole	0.5->32	93.1	87.5	90	100	100
Polymyxin B	0.25->8	2.8	4.2	0	4.3	0
Tigecycline	0.125-4	5.6	4.2	10	0	20

Note: CRE, carbapenem-resistant Enterobacteriaceae; MIC50/90, 50%/90% minimum inhibitory concentration; %R, % of isolates resistant; %S, % of isolates susceptible
*The resistance rate to amikacin in bla_KPC, bla_NDM, bla_KPC+NDM groups was statistically different from that of bla_{OXA−48−like} group (Chi-squared test, P < 0.05)

ISSN: 1755-8794