Occurrence and antimicrobial susceptibility profile of Escherichia coli O157:H7 from food of animal origin in Bishoftu town, Central Ethiopia

Table 1 Guidelines for antibiotic discs used for antimicrobial susceptibility test of E. coli with their respective concentrations

Antimicrobial agent	Symbol	Disc content	Zone of inhibition in millimeters (mm) with its interpretation
Antimicrobial agent	Symbol	Disc content	Susceptible	Intermediate	Resistant
Ceftriaxone	CRO	30 μg	≥ 23	20–22	≤ 19
Streptomycin	S	10 μg	≥ 15	12–14	≤ 11
Tetracycline	TTC	30 μg	≥ 15	12–14	≤ 11
Gentamycin	GN	10 μg	≥ 15	13–14	≤ 12
Ciprofloxacilin	CIP	5 μg	≥ 21	16–20	≤ 15
Vancomycin	VA	30 μg	≥ 12	10–11	≤ 9
Chloramphenicol	C	30 μg	≥ 18	13–17	≤ 12
Ampicillin	AMP	10 μg	≥ 14	12–13	≤ 11