Genetic Diversity and in vitro Activity of Aztreonam/Avibactam and Ceftazidime/Avibactam Against Carbapenem-Resistant Enterobacterales: A Multi-Center Study in Southwest China

Figures & data

Table 1 Characteristics of Carbapenemase Genes Among 312 CRE Clinical Isolates

Species	n	Carbapenemase Genes
		blaKPC, n	blaNDM/IMP, n	blaKPC + blaNDM/IMP, n
K. pneumoniae	206	blaKPC-2, 145	blaNDM-1, 21 blaNDM-5, 11 blaNDM-1+blaIMP4, 1	blaKPC-2+blaNDM-1, 17 blaKPC-2+blaIMP-4, 1 blaKPC-2+blaIMP-4+blaNDM-1, 1
E. coli	43	blaKPC-2, 1	blaNDM-5, 26 blaNDM-1, 8 blaIMP-4, 2	0
E. cloacae	42	blaKPC-2, 1	blaNDM-1, 28 blaNDM-5, 2 blaIMP-4, 2 blaNDM-1+blaIMP-4, 1	blaKPC-2+blaNDM-1, 2 blaKPC-2+blaIMP-2, 1
C. freumdii	7	0	blaNDM-1, 6 blaNDM-1+blaIMP-8, 1	0
K. oxytoca	6	0	blaNDM-1, 2 blaNDM-1+blaIMP-2, 2	0
K. aerogenes	4	0	blaNDM-1, 1 blaNDM-5, 1	blaKPC-2+blaNDM-1, 1
S. marcescens	2	0	blaNDM-5, 1	0
C. braakii	1	0	blaNDM-1, 1	0
P. rettgeri	1	0	blaNDM-1, 1	0

Table 2 Antimicrobial Susceptibility of 312 CRE Isolates and Different Isolates by Genotypes (MICs, μg/mL)

Antimicrobial Agent	Total (n = 312)				KPC Group (n = 147)				MBL Group (n = 118)				KPC-MBL Group (n = 23)				Non-CP Group (n = 24)
	%R	MIC Range	MIC50	MIC90	%R	MIC Range	MIC50	MIC90	%R	MIC Range	MIC50	MIC90	%R	MIC Range	MIC50	MIC90	%R	MIC Range	MIC50	MIC90
CAZ	98.4	≤1-≥64	≥64	≥64	99.3	8-≥64	≥64	≥64	99.2	≤1-≥64	≥64	≥64	100.0	≥64	≥64	≥64	87.5	≤1-≥64	≥64	≥64
CAZ/AVI	48.1	≤0.125-≥512	4	≥512	2.0	≤0.125-≥512	1	4	100.0	16-≥512	≥512	≥512	100.0	16-≥512	≥512	≥512	25.0	≤0.25-≥512	2	128
ATM	90.4	≤1-≥64	≥64	≥64	100.0	16-≥64	≥64	≥64	78.8	≤1-≥64	≥64	≥64	100.0	16-≥64	≥64	≥64	79.2	≤1-≥64	≥64	≥64
ATM/AVI	0.0	≤0.125–2	≤0.125	0.5	0.0	≤0.125–2	0.25	0.5	0.0	≤0.125–1	≤0.125	0.5	0.0	≤0.125–0.5	≤0.125	0.5	0.0	≤0.125–0.5	≤0.125	0.5
FEP	94.6	≤1-≥64	≥64	≥64	98.6	2-≥64	≥64	≥64	94.9	≤1-≥64	≥64	≥64	95.7	≤1-≥64	≥64	≥64	66.7	≤1-≥64	≥64	≥64
TZP	96.2	≤4-≥128	≥128	≥128	100.0	≥128-≥128	≥128	≥128	93.2	≤4-≥128	≥128	≥128	100.0	≥128-≥128	≥128	≥128	83.3	≤4-≥128	≥128	≥128
ETP	99.4	≤0.5-≥8	≥8	≥8	100.0	≥8-≥8	≥8	≥8	100.0.	4-≥8	≥8	≥8	100.0	4-≥8	≥8	≥8	91.7	≤0.5-≥8	≥8	≥8
IMP	95.5	≤1-≥16	≥16	≥16	100.0	8-≥16	≥16	≥16	98.3	2-≥16	≥16	≥16	95.7	≤1-≥16	≥16	≥16	54.2	≤1-≥16	4	≥16
MEM	96.2	≤1-≥16	≥16	≥16	100.0	4-≥16	≥16	≥16	97.5	≤1-≥16	≥16	≥16	95.7	≤1-≥16	≥16	≥16	66.7	≤1-≥16	8	≥16
GEN	80.1	≤1-≥16	≥16	≥16	92.5	≤1-≥16	≥16	≥16	66.9	≤1-≥16	≥16	≥16	91.3	≤1-≥16	≥16	≥16	58.3	≤1-≥16	≥16	≥16
TOB	72.4	≤1-≥16	≥16	≥16	92.5	≤1-≥16	≥16	≥16	50.0	≤1-≥16	8	≥16	87.0	≤1-≥16	≥16	≥16	45.8	≤1-≥16	8	≥16
AMK	61.5	≤2-≥64	≥64	≥64	92.5	≤2-≥64	≥64	≥64	28.0	≤2-≥64	≤2	≥64	82.6	≤2-≥64	≥64	≥64	16.7	≤2-≥64	≤2	≥64
CIP	85.6	≤0.25-≥4	≥4	≥4	99.3	0.5-≥4	≥4	≥4	67.8	≤0.25-≥4	≥4	≥4	100.0	1-≥4	≥4	≥4	75.0	≤0.25-≥4	≥4	≥4
LVX	81.7	≤0.25-≥8	≥8	≥8	99.3	1-≥8	≥8	≥8	61.0	≤0.25-≥8	≥8	≥8	91.3	1-≥8	≥8	≥8	66.7	≤0.25-≥8	≥8	≥8
NIT	59.0	≤16-≥512	256	≥512	96.4	64-≥512	≥512	≥512	26.3	≤16-≥512	32	≥512	83.3	≤16-≥512	≥512	≥512	/	/	/	/
SXT	63.1	≤1-≥16	≥16	≥16	58.5	≤1-≥16	≥16	≥16	65.3	≤1-≥16	≥16	≥16	82.6	≤1-≥16	≥16	≥16	62.5	≤1-≥16	≥16	≥16

Notes: R, resistance; /MICs of NIT were not analyzed in Non-CP group because of limited number of strains.

Abbreviations: CAZ, ceftazidime; AVI, avibactam; ATM, aztreonam; FEP, cefepime; TZP, piperacillin/tazobactam; ETP, ertapenem; IMP, imipenem; MEM, meropenem; GEN, gentamicin; TOB, tobramycin; AMK, amikacin; CIP, ciprofloxacin; LVX, levofloxacin; NIT, nitrofurantoin; SXT, trimethoprim/sulfamethoxazole.

Figure 1 The MICs distribution of CAZ/AVI against 147 CRE isolates carrying single bla_KPC gene.

Figure 2 The MICs distribution of ATM/AVI against 312 CRE isolates.