Characterization of Indolicidin

Indolicidin was characterized for minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) (Table 1), in vitro stability (temperature, proteases, physiological concentration of salts) assays, in vitro safety (hemolysis and cytotoxicity) assays (Supplementary Files S1–S3 and Supplementary Files S3–S6). The membrane permeabilization effect of Indolicidin on MDR-EAEC strains (n = 3) was assessed by flow cytometry while, the outer and inner membrane permeability of MDR-EAEC isolates treated with MIC (1X and 2X) values of Indolicidin was carried out based on the nitrocefin activity as well as release of cytoplasmic β-galactosidase activity, respectively (Supplementary Files S4–S6). Further, Indolicidin was evaluated for its antibacterial effect against commensal gut flora (Lactobacillus rhamnosus MTCC 1408 and Lactobacillus acidophilus MTCC 10307) (Supplementary File S7).

MIC and MBC observed for Indolicidin against MDR-EAEC isolates.