TABLE 4.

Performance of rapid antimicrobial susceptibility testing of Gram-negative rods (n = 36)

Antimicrobial agent	No. of isolate-antibiotic combinationsb	No. of isolates that werea:		No. (%) of errors			Categorical agreement (%)	Essential agreement (%)
		Resistant	Susceptible	Very major	Major	Minor
Ampicillin	35	29	6				100	100
Ampicillin-sulbactam	35	20	15		1		97.1	97.1
Piperacillin	1	0	0				100	100
Piperacillin-tazobactam	36	9	18			2	94.4	97.2
Cefuroxime	35	16	19				100	100
Cefuroxime axetil	35	15	20				100	100
Cefotaxime	36	10	26			1	97.2	97.2
Cefpodoxime	35	14	21				100	100
Ceftazidime	36	4	25				100	100
Cefepime	1	0	1				100	100
Ertapenem	35	0	35		1		97.1	97.1
Imipenem	36	0	35				100	100
Meropenem	36	0	35				100	100
Aztreonam	1	0	0				100	100
Ciprofloxacin	36	10	26				100	100
Moxifloxacin	35	10	25				100	100
Gentamicin	36	1	34				100	100
Amikacin	1	0	1				100	100
Tobramycin	1	0	1				100	100
Tetracycline	35	16	19			1	97.1	100
Tigecycline	35	1	29			1	97.1	100
Trimethoprim-sulfamethoxazole	36	14	22				100	100
Colistin	1	0	1				100	100
Total	609	169	414	0	2 (0.5)	5 (0.8)	99.2	99.3

^aThe number of results in the intermediate category can be calculated by subtracting the resistant and susceptible results from the number of isolate-antibiotic combinations tested.

^bOne as a number of isolate-antibiotic combinations for some antibiotics is due to the fact that those antibiotics are analyzed only in the card AST-N248, which was used for testing of the only isolate of P. aeruginosa.