Table 1.

Antibiotic disks used to test E. coli O157:H7 and their respective concentrations.

No.	Antibiotic disks	Disk code	Concentration	Diameter of zone of inhibition in millimeters (mm)
				Resistant ≤	Intermediate	Susceptible ≥
1	Ampicillin	AM	10 μg	13	14–16	17
2	Amoxycillin-clavulanic acid	AMC	20/10 μg	13	14–17	18
3	Amikacin	AK	30 μg	14	15–16	17
4	Ciprofloxacin	CIP	5 μg	15	16–20	21
5	Ceftriaxone	CRO	30 μg	19	20–22	23
6	Cefoxitin	FOX	30 μg	14	15–17	18
7	Nitrofurantoin	F/M	50 μg	14	15–16	17
8	Kanamycin	K	30 μg	13	14–17	18
9	Nalidixic acid	NA	30 μg	13	14–18	19
10	Sulfamethoxazole- trimethoprim	SXT	25 μg	10	11–15	16
11	Tetracycline	TE	30 μg	11	12–14	15
12	Streptomycin	S	10 μg	11	12–14	15
13	Gentamicin	GM	10 μg	12	13–14	15