Table 1:

Susceptibility of Escherichia coli clinical isolates to colistin, stratified by study year

YearNo. of isolates% susceptible*% resistant*
2008113099.9 (1129/1130)0.1 (1/1130)
2009109799.9 (1096/1097)0.1 (1/1097)
2010101399.5 (1008/1013)0.5 (5/1013)
2012499100.0 (499/499)0.0 (0/499)
201365599.7 (653/655)0.3 (2/655)
2014618100.0 (618/618)0.0 (0/618)
201555999.5 (556/559)0.5 (3/559)
  • Note: MIC = minimum inhibitory concentration.

  • * European Committee on Antimicrobial Susceptibility Testing breakpoints for colistin v. Enterobacteriaceae: an MIC of 2 μg/mL or less is defined as susceptible; an MIC of 4 μg/mL or more is defined as resistant.