Impedance-based biosensor as a promising tool for rapidly detecting the formation of multidrug-resistant Pseudomonas aeruginosa biofilms.

AIMS: To evaluate the use of an impedimetric biosensor for studying Pseudomonas aeruginosa biofilms, with particular emphasis on multidrug-resistant (MDR) P. aeruginosa variants.

MATERIALS AND

METHODS

Included in this work were 16 clinical MDR P. aeruginosa strains, which had been previously isolated from respiratory secretions of children with cystic fibrosis (CF) with chronic lung infections, in addition to the reference strains ATCC® 15692™ and ATCC® 27853™. The P. aeruginosa biofilms were studied over a total of 72 h using the standard crystal violet (CV) staining method, whereas impedance measurements with the biosensor were performed every 20 min.

RESULTS

The impedances detected from 24 h, 48 h, and 72 h did not correlate with the CV staining data at the same time points; however, there were negative correlations among the impedance detected at 100 min, and the forming biofilms at 48 h and 72 h identified using the CV method, where the strongest correlation was identified at 100 min (1:40 h) (ρ = -0.49; p < 0.01, Spearman's ρ).

CONCLUSIONS

Therefore, this biosensor could be useful for inferring MDR P. aeruginosa biofilm formation in less than 2 h.