Novel Antisense-Peptide Nucleic Acids to Prevent Bacterial Biofilm Among Gram-Negative Bacteria Implicated in Catheter-Associated Urinary Tract Infections

Biofilms develop in sequential steps resulting in the formation of three-dimensional communities of microorganisms that are encased in self-produced extracellular polymeric substances. Biofilms play a key role in device-associated infections, such as catheter-associated urinary tract infections (CAUTIs), because they protect microorganisms from standard antimicrobial therapies. Current strategies to prevent biofilm formation in catheter-related infections, including prophylactic antibiotics and antibiotic-coated catheters, have been unsuccessful, highlighting a need for novel technologies. In this study, biofilm-forming phenotypes of common Gram-negative bacteria associated with CAUTIs were treated with antisense-peptide nucleic acids (PNAs) and biofilm biomass and bacterial viability were quantified after 24 or 48 hours of treatment. A cocktail of PNAs targeting the global regulator genes rsmA , amrZ , and rpoS in Pseudomonas aeruginosa significantly reduced biofilm biomass and viability. Antisense-wide-range PNAs against these same gene targets and the motility regulator gene motA inhibited biofilm formation among isolates of Klebsiella pneumoniae , Enterobacter cloacae , Escherichia coli , and Proteus mirabilis , but did not reduce bacterial viability. These results suggest that antisense-PNAs are a promising new technology in preventing biofilm formation in urinary catheters, especially as a potential complement to conventional antimicrobials.