The impact of a cation channel blocker (furosemide) on Pseudomonas aeruginosa PAO1 biofilm architecture.

OBJECTIVE

To determine if furosemide could have a role in inhibition of biofilm formation.

STUDY

DESIGN

A prospective study of 72-hour biofilms grown in the Calgary Biofilm Device (CBD) treated with furosemide and controls.

METHODS

Bacteria were treated with furosemide and controls to determine its antiplanktonic properties. PA01 biofilms were treated with serial 2-fold dilutions of furosemide and controls over a 48-hour period at pH concentrations of 7.0, 8.0, and 9.0.

RESULTS

Furosemide had no effect on planktonic PA01. It had minimal effect at pH below 8.0. A pH of 8.0 and 9.0 reduced biofilms 25%. Furosemide 10 mg/mL reduced biofilms 50% at pH 8.0 and 9.0. It inhibited biofilms to < 30% at concentrations of 0.6 to 0.16 mg/mL at pH 8.0 and < 10% at concentrations of 1.25 to 0.3 mg/mL at pH 9.0.

CONCLUSION

Furosemide was found to be nonantiplanktonic, but does appear to destabilize preformed PA01 biofilms at pH-dependent concentrations.