Antibiotics promoting oxidative stress inhibit formation of Escherichia coli biofilm via indole signalling.
Recent studies have revealed that antibiotics can promote the formation of reactive oxygen species which contribute to cell death. In this study, we report that five different antibiotics known to stimulate production of reactive oxygen species inhibited growth of Escherichia coli biofilm. We demonstrated that supression of biofilm formation was mainly a consequence of the increase in the extracellular concentration of indole, a signal molecule which suppresses growth of bacterial biofilm. Indole production was enhanced under antibiotic-mediated oxidative stress due to overexpression of tryptophanase (TnaA), which catalyzes synthesis of indole. We found that DMSO (dimethyl sulfoxide), a hydrogen peroxide scavenger, or the lack of trypthophanase, which catalyzes production of indole, partly restored formation of E. coli biofilm in the presence of antibiotics. In conclusion, these findings confirmed that antibiotics which promote formation of ROS (reactive oxygen species) can inhibit development of E. coli biofilm in an indole-dependent process.
Kuczyńska-Wiśnik
Dorota
D
Department of Biochemistry, Faculty of Biology, University of Gdańsk, Kładki 24, 80-952 Gdańsk, Poland. wisnik@biotech.ug.gda.pl
Matuszewska
Ewelina
E
Furmanek-Blaszk
Beata
B
Leszczyńska
Daria
D
Grudowska
Alicja
A
Szczepaniak
Paweł
P
Laskowska
Ewa
E
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development*; D004121:Dimethyl Sulfoxide / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D016166:Free Radical Scavengers / Q000378:metabolism; D020869:Gene Expression Profiling; D007211:Indoles / Q000378:metabolism*; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D014368:Tryptophanase / Q000096:biosynthesis
D000900:Anti-Bacterial Agents; D016166:Free Radical Scavengers; D007211:Indoles; D017382:Reactive Oxygen Species; C030374:indole; D014368:Tryptophanase; D004121:Dimethyl Sulfoxide