Table 3.

Concordance of genotypic and phenotypic resistance in bla_CTX-M-harbouring Escherichia coli

Antibiotic substanceb	blaCTX-M, n = 80a						blaCTX-M-positive ESBL-producers, n = 58a						blaCTX-M-positive non ESBL producers, n = 22a
	S		I		R		S		I		R		S		I		R
	n	%	n	%	n	%	n	%	n	%	n	%	n	%	n	%	n	%
AM	0	–	0	–	80	100	0	–	0	–	58	100	0	–	0	–	22	100
AMC	48	60	9	11.3	23	28.8	40	69	9	15.5	9	15.5	8	36.4	0	–	14	63.6
TZP	64	80	9	11.3	7	8.8	51	87.9	6	10.3	1	1.7	13	59.1	3	13.6	6	27.3
CAZ	35	43.8	1	1.3	44	55	27	46.6	1	1.7	30	51.7	8	36.4	0	–	14	63.6
CTX	11	13.8	0	–	69	86.3	0	–	0	–	58	100	11	50	0	–	11	50
FEPc	37	50	10	13.5	27	36.5	29	55.8	8	15.4	15	28.8	8	36.4	2	9.1	12	54.5
ETP	77	96.3	2	2.5	1	1.3	57	98.3	1	1.7	0	–	20	90.9	1	4.5	1	4.5
IPM	80	100	0	–	0	–	58	100	0	–	0	–	22	100	0	–	0	–
MEM	80	100	0	–	0	–	58	100	0	–	0	–	22	100	0	–	0	–
AN	78	97.5	1	1.3	1	1.3	58	100	0	–	0	–	20	90.9	1	4.5	1	4.5
GM	52	65	3	3.8	25	31.3	39	67.2	1	1.7	18	31	13	59.1	2	9.1	7	31.8
CIP	18	22.5	1	1.3	61	76.3	14	24.1	1	1.7	43	74.1	4	18.2	0	–	18	81.8

AMC: Amoxicillin/Clavulanic acid; TZP: Piperacillin/Tazobactam; ESBL: extended spectrum beta lactamase; CTX: Cefotaxime; CAZ: Ceftazidime; FEP: Cefepime; AN: Amikacin; CIP: Ciprofloxacin; S: susceptible; I: intermediate; R: resistant

^aMay not add up to 100% due to rounding errors to 1 decimal place

^bInterpretation of resistance according to the clinical breakpoints of CLSI

^c6 missing values for cefepime