Electrical sensor system for in vitro bacteria biofilm diagnostics

Bacterial biofilm is a complex community of microbes that contributes to the formation of bacterial resistance to adverse environmental factors. Detection and analysis of biologically active compounds indicative of biofilm development is a promising direction in the diagnosis of biofilm formation. This paper describes the possibility of detecting surface changes in Pseudomonas bacteria when they change from planktonic to biofilm form. These surface changes were detected through the conformational changes in the outer membrane components, including lipopolysaccharide (LPS). The electrophysical profile of the same strain differed largely between planktonic and biofilm cultures. The monosaccharide and fatty acid composition and the electrophoretic mobility of cell surface LPS and the biofilm matrix polysaccharides of P. putida TSh-18 were characterized. In the LPS of biofilm cells, rhamnose and glucose residues prevailed; in the biofilm matrix polysaccharides, rhamnose, mannose, and glucose residues prevailed. The fatty acid composition of the LPS of biofilms was similar to that of the LPS of planktonic cells. The biofilms contained both S- and R-form LPS. The results are promising for the development of an electrical sensor method for the rapid in vitro diagnostics of the initial phase of bacterial biofilm formation and timely blocking of biofilm communities. •Electrical sensor system for in vitro bacterial biofilm diagnostics was described.•Correlations between the changes of LPS and electrophysical properties during biofilms formation were established.•Fatty acid and monosaccharide composition of EPM and biofilm LPS were characterized.•LPS of planktonic and biofilm forms significantly differed in monosaccharide composition.•EPM of biofilms contained polysaccharides (62%) with rhamnose, mannose, and glucose residues, as well as proteins (15%).