colistin and indole

Combinations of polymyxins and phytochemicals were tested for antimicrobial activity against two gram-negative bacteria. Various degrees of potentiation were found against Pseudomonas aeruginosa and Escherichia coli with (E)-2-hexenal and indole. Three-compound combinations were found to further increase the activity of polymyxin B sulfate and colistin methanesulfonate against both bacteria. Combinations with colistin against P. aeruginosa resulted in the highest degree of potentiation, with a 512-fold increase in colistin antimicrobial activity. These results indicate the potential efficacy of phytochemical combinations with antibiotics to enhance total biological activity.

Topics: Anti-Bacterial Agents; Colistin; Drug Combinations; Drug Synergism; Escherichia coli; GABA Modulators; Hexobarbital; Indoles; Microbial Sensitivity Tests; Polymyxin B; Pseudomonas aeruginosa