Inhibition of biofilm formation by the antisense peptide nucleic acids targeted at the motA gene in Pseudomonas aeruginosa PAO1 strain

Pseudomonas aeruginosa is a ubiquitous bacterium which is able to attach to many abiotic and biotic surfaces and form biofilms resulting in infections. The motA gene was an essential gene in the early phase of biofilm formation of P. aeruginosa PAO1. In this study, antisense peptide nucleic acids (PNAs) and PNAs conjugated with the peptide (KFF)(3)K were used to investigate whether they could mediate gene-specific antisense effects in P. aeruginosa PAO1. We found that antisense (KFF)(3)K-PNA targeted at motA gene could inhibit biofilm formation in P. aeruginosa PAO1 in a dose-dependent manner. The minimal effective concentration of this antisense agent was 1 mu mol l(-1), and the inhibited effect could last for at least 8 h. When compared with the control group, the value of OD570 of P. aeruginosa PAO1 reduced apparently when treated with (KFF)(3)K-PNA. The expression of motA was sharply reduced when treated with (KFF)(3)K-PNA, but reduced slightly when treated with PNA, and had no reduction when treated with (KFF)(3)K. Our results demonstrated that the cell-penetrating peptide of (KFF)(3)K improved significantly the antisense inhibition effect of PNA. The (KFF)(3)K-PNA conjugates might be used as antisense agent for inhibition of the biofilm formation. This provides exciting possibility for developing new tool for microbial genetic treatment.