Table 1.

Antimicrobial susceptibility of clinical isolates of Gram-negative bacilli collected in Belgium, Norway, Sweden and Switzerland (combined) during 2017–21

		% Susceptible
Organism	n	C/T	IPM/REL	MEM	IPMa,b	ETP	FEPb	CAZb	CRO	TZPb	LVXb,c	AMK	CST
Enterobacterales	4158	95.0	NA	99.4	99.5	97.9	87.5	82.0	81.4	84.9	84.9	98.6	85.0
NME	3833	94.7	99.6	99.4	99.1	97.7	86.7	81.3	80.6	83.7	85.0	98.7	92.1
E. coli	1842	98.9	99.9	99.8	99.8	99.5	85.6	84.4	84.6	89.0	79.1	98.9	99.7
ESBL non-CREd	276	94.9	100	100	100	100	15.9	9.8	0	75.7	35.5	94.9	99.3
K. pneumoniae	654	95.4	98.6	98.3	98.6	97.6	81.0	79.5	81.5	80.9	83.2	98.0	98.0
ESBL non-CREd	108	85.2	100	99.1	100	100	8.3	3.7	0	44.4	32.1	98.1	96.3
P. aeruginosa	823	95.7	94.5	81.7	80.0	NA	80.9	79.1	NA	77.0	84.2	93.6	99.9
FEP resistant	157	78.3	74.5	42.0	42.0	NA	0	15.3	NA	17.2	58.6	73.2	99.4
CAZ resistant	172	80.2	77.9	45.9	45.9	NA	22.7	0	NA	11.0	63.4	78.5	99.4
MEM resistant	54	55.6	42.6	0	3.7	NA	14.8	11.1	NA	3.7	24.1	63.0	98.1
TZP resistant	189	83.1	80.4	47.6	49.7	NA	31.2	19.0	NA	0	62.4	83.1	99.5
		% Susceptible

C/T, ceftolozane/tazobactam; IPM/REL, imipenem/relebactam; MEM, meropenem; ETP, ertapenem; FEP, cefepime; CAZ, ceftazidime; CRO, ceftriaxone; TZP, piperacillin/tazobactam; LVX, levofloxacin; AMK, amikacin; CST, colistin; NA, not applicable or MIC breakpoint not available.

^aThe results provided for Enterobacterales combine % susceptible, increased exposure values for Morganellaceae and % susceptible values for NME.⁶

^bThe results provided for P. aeruginosa are % susceptible, increased exposure values.⁶

^cLevofloxacin was only tested against Enterobacterales isolates from 2018 to 2021.

^dESBL non-CRE was defined by an isolate testing with a ceftriaxone MIC of ≥2 mg/L and an ertapenem MIC of ≤0.5 mg/L.