Abstract
Biofilm formation on endotracheal tubes (ETT) is an important factor in the development of ventilator-associated pneumonia (VAP). This work aimed to investigate the effectiveness of colistin (COL) against the early stages of biofilm formation by Pseudomonas aeruginosa. Two strategies were used: pre-conditioning the adhesion surfaces with COL before biofilm formation and growing biofilms in its presence. The combined effect of treating P. aeruginosa 24-hours old biofilms with Ciprofloxacin (CIP) or colistin (COL) on clean and COL-conditioned surfaces was also assessed. Random deposition of COL residues altered the physico-chemical properties of the adhesion surfaces and impaired biofilm formation. Moreover, as a consequence of the reduced amount of biofilms attached to COL conditioned surfaces, adhered cells became more exposed to the subsequent action of CIP or COL, suggesting a combined outcome of prophylactic and therapeutic COL-based strategies. Results highlighted the promising use of COL to prevent the establishment of biofilms on ETT.
Disclosure statement
The authors declare that they have no conflict of interest with the subject.