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Table 1 Viability (%) of each Escherichia coli isolate after different antibiotic treatments with and without exposure to benzalkonium chloride, expressed as mean +/− standard deviation

From: Effect of subinhibitory exposure to quaternary ammonium compounds on the ciprofloxacin susceptibility of Escherichia coli strains in animal husbandry

E. coli isolate - originMIC
(mg/L CIP)
CIP treatment (mg/L)SubpopulationNo BKC exposureBKC exposure
KL6; Poultry0.120;
Resistant (non-WT)
0.000Live98.44±0.5161.40±2.10
 Intermediate0.35±0.1720.71±0.79
 Dead0.17±0.0416.89±1.64
0.064Live97.15±0.8287.57±0.93
Intermediate1.02±0.559.77±1.02
Dead0.38±0.191.54±0.77
0.640Live76.03±3.5258.75±3.20
Intermediate18.73±4.1235.67±2.58
Dead2.97±0.342.94±0.24
6.400Live25.80±3.4449.32±3.57
Intermediate68.14±2.3744.96±4.84
Dead5.12±1.274.38±0.77
KQ26; Poultry0.030; Susceptible* (WT)0.000Live97.03±0.3079.47±2.08
 Intermediate0.95±0.184.17±0.58
 Dead1.62±0.2815.70±1.38
0.064Live51.55±0.8878.27±2.95
Intermediate42.48±1.3217.34±2.13
Dead4.95±0.412.17±0.16
0.640Live64.12±2.4363.73±5.40
Intermediate30.96±1.6431.46±5.65
Dead3.57±0.643.48±0.12
6.400Live83.16±1.6070.69±1.51
Intermediate12.91±1.3026.86±1.50
Dead2.69±0.241.52±0.19
VA57; Pork0.030; Susceptible* (WT)0.000Live93.97±0.3050.50±4.41
 Intermediate1.37±0.029.88±0.66
 Dead3.93±0.3138.66±4.93
0.064Live51.75±2.6053.87±9.77
Intermediate34.45±3.6035.97±7.70
Dead12.68±3.328.71±2.47
0.640Live69.72±2.0951.10±3.74
Intermediate14.59±0.6340.18±2.64
Dead13.93±1.337.71±1.42
6.400Live67.12±7.4949.07±7.07
Intermediate26.31±5.7944.51±7.12
Dead5.59±1.755.27±0.05
ATCC 10536≤ 0.015; Susceptible* (WT)0.000Live88.62±2.2954.84±2.09
 Intermediate2.74±0.226.76±1.39
 Dead7.89±2.0937.07±2.04
0.064Live67.56±3.6841.25±1.33
Intermediate22.19±3.7954.12±2.47
Dead7.67±0.504.07±0.27
0.640Live55.73±6.1739.37±2.91
Intermediate38.62±7.9556.31±2.47
Dead4.42±1.443.66±0.65
6.400Live52.92±6.9627.46±4.16
Intermediate44.05±5.5667.88±4.45
Dead2.34±1.154.06±2.69
  1. MIC Minimal Inhibitory Concentration, CIP ciprofloxacin, WT wild type; *susceptible/resistant to CIP, defined by the epidemiologic cutoff value (ECOFF, 0.064 mg/L CIP) separating the bacterial population into those without (wild type; <= 0.064 mg/L CIP ), and those with acquired resistance (non-wild type; > 0.064 mg/L CIP)