TABLE 4

Checkerboard assay results for antibiotic-compound 79 synergy in E. coli ATCC 25922 and MDR CTX-M-15-producing ST131 strains

Antibiotic or compoundATCC 25922ST131
MIC aloneaMIC at FIC indexbFIC indexcMIC aloneMIC at FIC indexFIC index
Erythromycin1610.19256160.19
Fusidic acid500160.1650040.14
Novobiocin160.50.161620.25
Rifampin20.030.1440.250.19
Compound 7920.25NAd20.25NA
  • a MIC of each antibiotic (μg/ml) or compound (μM) individually.

  • b MIC in compound-antibiotic combination at the lowest fractional inhibitory concentration index.

  • c FIC index, fractional inhibitory concentration index.

  • d NA, not applicable.