Polyamines as regulators of biofilm formation in Escherichia coli isolates with different levels of fluoroquinolone resistance

Fluoroquinolone-resistant Escherichia coli isolates were shown to have an elevated ability to form biofilms and possess by increased activity of ornithine decarboxylase, the key enzyme of polyamine synthesis. Upregulation of biofilm formation under sublethal fluoroquinolone treatment was observed. Putrescine and spermidine were found to have positive effect on biofilm formation in strains with different levels of levofloxacin resistance in both the presence of this antibiotic and its absence.