Genetic Diversity of Escherichia coli Coharboring mcr-1 and Extended Spectrum Beta-Lactamases from Poultry

Table 2

Minimum inhibitory concentration distribution of colistin-resistant Escherichia coli isolates.

Antimicrobial agents	Breakpoints	No. of isolates with MIC (μg/ml) of
		≤0.25	0.5	1	2	4	8	16	32	64	128	≥256
Amikacin	≥64	—	—	—	6	4	3	—	—	4	11	7
Gentamicin	≥16	—	—	2	1	—	—	1	12	11	7	1
Tobramycin	≥16	—	—	8	13	2	—	1	6	2	3	—
Ciprofloxacin	≥1	11	—	—	—	—	2	12	5	4	1	—
Cefotaxime	≥4	2	6	1	—	—	1	9	12	3	1	—
Ceftazidime	≥16	—	1	7	1	—	—	—	2	16	7	1
Cefepime	≥16	2	3	4	—	—	—	2	6	15	3	—
Imipenem	≥4	25	10	—	—	—	—	—	—	—	—	—
Meropenem	≥4	20	11	4	—	—	—	—	—	—	—	—
Colistin	≥4	—	—	—	—	20	14	1	—	—	—	—
Tigecycline	≥8	13	19	3	—	—	—	—	—	—	—	—