Antimicrobial Resistance of Uropathogenic Escherichia coli from Elderly Patients at a General Hospital, Argentina

Table 1: Antimicrobial resistance in Escherichia coli isolated from elderly patients with urinary tract infections.

ATM	I (%)	R (%)	MIC Range (µg/mL)	MIC₅₀ (µg/mL)	MIC₉₀ (µg/mL)
Ampicillin	0	80.5	≤2-64	32	64
AMC^a	3.1	28.6	≤2-64	4.0	64
Cefazolin	46.2	21.6	≤1-64	4.0	32
Cefuroxime	0	20.7	1-32	2.0	32
Cefoxitin	11.2	3.1	1-32	1.0	32
Cefotaxime	0	9.7	≤1-64	0.25	2.0
Ceftazidime	0	9.7	≤4-64	0.25	2.0
Cefepime	0	8.4	0.5-32	0.50	8.0
Ertapenem	0	0	≤0.25-0.5	0.12	0.5
Imipenem	0	0	≤0.25-1	0.12	0.50
Gentamicin	0.9	13.8	≤0.5-128	0.50	64
Nalidixic acid	0.1	61.7	≤16-64	32	64
Ciprofloxacin	3.0	42.8	≤0.25-8	0.12	8.0
TMS^b	0.1	37.6	2-320	2.0	160
Nitrofurantoin	0	2.3	2-128	4.0	32

ATM, antimicrobial; I, intermediate susceptibility; R, resistance; AMC, amoxicillin-clavulanate; TMS, trimethoprim-sulfamethoxazole. MIC, Minimum inhibitory concentration. ^aFor MICs determination, the concentration of clavulanic acid was fixed at 2 µg/mL. ^bTMS in the ratio 1:19. MICs values are expressed as the trimethoprim concentration.