Table 3.

Categorical agreement and errors for direct AST compared with culture-dependent AST in Gram-negative bacteria.

Microorganisms	Antimicrobial agents	No.	Category agreement		Minor error		Major error		Very major error
Enterobacteriaceae (n = 72)	Ampicillin	72	71	98.61%			1	1.39%
	Ampicillin/Sulbactam	72	61	84.72%	11	15.28%
	Piperacillin/Tazobactam	72	71	98.61%	1	1.39%
	Cefazolin	72	70	97.22%			2	2.78%
	Cefotetan	72	71	98.61%	1	1.39%
	Ceftazidime	72	68	94.44%	4	5.56%
	Ceftriaxone	72	72	100%
	Cefepime	72	61	84.72%	9	12.5%	2	2.78%
	Aztreonam	72	67	93.05%	2	2.78%	2	2.78%	1	1.39%
	Ertapenem	72	70	97.22%			2	2.78%
	Imipenem	72	67	93.05%	5	6.95%
	Amikacin	72	70	97.22%	2	2.78%
	Gentamicin	72	71	98.61%			1	1.39%
	Tobramycin	72	62	86.11%	10	13.89%
	Ciprofloxacin	72	72	100%
	Levofloxacin	72	72	100%
	Nitrofurantoin	72	61	84.72%	9	12.5%	2	2.78%
	Sulfamethoxazole/Trimethoprim	72	72	100%
Non-fermenting Gram-negative bacilli (n = 18)	Ampicillin	18	18	100%
	Ampicillin/Sulbactam	18	18	100%
	Piperacillin	18	16	88.89%	1	5.56%	1	5.56%
	Piperacillin/Tazobactam	18	18	100%
	Cefazolin	18	18	100%
	Cefuroxime	18	18	100%
	Cefuroxime Axetil	18	18	100%
	Cefotetan	18	18	100%
	Ceftazidime	18	16	88.89%	2	11.11%
	Ceftriaxone	18	16	88.89%			1	5.56%	1	5.56%
	Cefepime	18	17	94.44%	1	5.56%
	Aztreonam	18	14	77.78%	1	5.56%	3	16.67%
	Imipenem	18	14	77.78%	3	16.67%			1	5.56%
	Meropenem	18	16	88.89%	2	11.11%
	Amikacin	18	18	100%
	Gentamicin	18	17	94.44%	1	5.56%
	Tobramycin	18	18	100%
	Ciprofloxacin	18	17	94.44%			1	5.56%
	Levofloxacin	18	18	100%
	Nitrofurantoin	18	17	94.44%					1	5.56%
	Sulfamethoxazole/Trimethoprim	18	17	94.44%					1	5.56%