Identification of Pathogenic Factors in Klebsiella pneumoniae Using Impedimetric Sensor Equipped with Biomimetic Surfaces

K. pneumoniae is an opportunistic pathogen that causes nosocomial infections, such as, pneumonia, urinary tract infections, septic shock, and gastro intestinal disease. Lipopolysaccharide (LPS), capsular polysaccharide, and fimbriae are recognized major virulence factors of K. pneumoniae and play key roles during early stages of infections. In this study, we functionalized the surface of gold electrode with mannose and mucin to monitor the adhesion-associated virulence factors of K. pneumoniae. The binding characteristics of K. pneumoniae 2242 wild type and of its isogenic mutants lacking outer-core LPS (D wabG) or fimbriae (D fimA) were investigated using Faradaic impedance spectra. The results obtained showed fimbriae are responsible for K. pneumoniae adhesion to the mannose of glycoprotein on the surfaces of epithelial cells, whereas outer-core LPS and capsular polysaccharide are associated with specific binding to mucous. These results concurred with those of a conventional in vitro assay using human ileocecal epithelial cell (HCT-8 cells) and a human bladder epithelial cell (T-24), indicating that the devised method could be useful for investigating virulence-associated interactions of pathogenic bacteria with specific host cells and organs.