Table 3.

Summary of results^a with the six different methods

Method	All isolates (n = 107)			Groups 1 and 2 (n = 53)			Group 3 (n = 54)
	In (%)	Se (%)	Sp (%)	In (%)	Se (%)	Sp (%)	In (%)	Se (%)	Sp (%)
Disk diffusion (30 mm, MH agar)
CTX	0	75	98	0	90	93	0	31	100
CAZ	0	69	100	0	85	100	0	23	100
FEP	0	89	98	0	90	93	0	85	100
CPD	0	35	100	0	46	100	0	0b
ATM	0	90	100	0	90	100	0	93	100
CTX + CAZ	0	77	98	0	90	93	0	39	100
CTX + FEP	0	94	98	0	97	93	0	85	100
CTX + CPD	0	75	98	0	90	93	0	31	100
CTX + ATM	0	94	98	0	95	93	0	92	100
CAZ + FEP	0	92	98	0	95	93	0	85	100
CAZ + CPD	0	69	100	0	85	100	0	23	100
CAZ + ATM	0	92	100	0	92	100	0	92	100
FEP + CPD	0	90	98	0	92	93	0	85	100
FEP + ATM	0	92	98	0	92	93	0	92	100
CPD + ATM	0	92	100	0	92	100	0	92	100
CTX + CAZ + CPD	0	79	98	0	90	93	0	46	100
CAZ + CPD + ATM	0	92	100	0	92	100	0	92	100
CTX + FEP + (CAZ or CPD or ATM)	0	96	98	0	97	93	0	92	100
Any other association of three antibiotics	0	94	98	0	95	93	0	92	100
CAZ + CPD + ATM + (CTX or FEP)	0	94	98	0	95	93	0	92	100
Any other association of four or five antibiotics	0	96	98	0	97	93	0	92	100
Vitek2 card
N017	31	64	56	23	77	50	39	23	59
N017 + extended card	25	79	53	9	95	43	41	31	56
N052	27	65	60	15	80	71	39	23	56
N052 + extended card	26	73	56	6	92	79	46	15	49
Cica-Beta test
ESBL or multidrug resistance	14	75	80	15	74	57	13	77	88
ESBL Etest strip (MH agar)
CTX	49	71	29	19	87	50	78	23	22
CAZ	49	62	35	21	74	64	76	23	24
FEP	11	90	89	2	97	79	6	69	93
CTX + CAZ	49	73	27	19	87	50	78	31	20
CTX + FEP	39	90	29	11	97	50	67	69	22
CAZ + FEP	38	90	31	11	97	50	65	69	24
CTX + CAZ + FEP	40	90	27	11	97	50	69	69	20
Combined disk (MH agar)
CCTX	0	85	89	0	97	86	0	46	90
CCAZ	0	75	91	0	85	93	0	46	90
CFEP	0	89	89	0	90	93	0	85	88
CCTX + CCAZ	0	85	86	0	97	86	0	46	85
CCTX + CFEP	0	96	84	0	100	86	0	85	83
CCAZ + CFEP	0	92	82	0	95	86	0	85	81
CCTX + CCAZ + CFEP	0	96	80	0	100	86	0	85	78
Double disk diffusion (20 mm, MH agar)
CTX	0	87	98	0	100	93	0	46	100
CAZ	0	85	100	0	97	100	0	46	100
FEP	0	100	98	0	100	93	0	100	100
CPD	0	83	96	0	95	86	0	46	100
ATM	0	100	96	0	100	86	0	100	100
CTX + CAZ	0	87	98	0	100	93	0	46	100
CTX + CPD or CAZ + CPD	0	87	96	0	100	86	0	46	100
CTX + FEP or CAZ + FEP	0	100	98	0	100	93	0	100	100
Any other association of two antibiotics	0	100	96	0	100	86	0	100	100
CTX + CAZ + CPD	0	87	96	0	100	86	0	46	100
CTX + CAZ + FEP	0	100	98	0	100	93	0	100	100
Any other association of three, four, or five antibiotics	0	100	96	0	100	86	0	100	100

^aIn, percentage of indeterminate results.

^bNo synergy was observed with cefpodoxime among group 3 Enterobacteriaceae isolates.