Rapid Killing and Biofilm Inhibition of Multidrug-Resistant Strains and Other Microbes by Iodoindoles

Multi-drug resistant is well-known for its rapid acclimatization in hospital environments. The ability of the bacterium to endure desiccation and starvation on dry surfaces for up to a month results in outbreaks of health care-associated infections. Previously, indole and its derivatives were shown to inhibit other persistent bacteria. We found that among 16 halogenated indoles, 5-iodoindole swiftly inhibited growth, constrained biofilm formation and motility, and killed the bacterium as effectively as commercial antibiotics such as ciprofloxacin, colistin, and gentamicin. 5-Iodoindole treatment was found to induce reactive oxygen species, resulting in loss of plasma membrane integrity and cell shrinkage. In addition, 5-iodoindole rapidly killed three strains, , and the fungus , but did not inhibit the growth of . This study indicates the mechanism responsible for the activities of 5-iodoindole warrants additional study to further characterize its bactericidal effects on antibiotic-resistant and other microbes.