Cytochemical Differences in Bacterial Glycocalyx

Abstract

To examine new cytochemical aspects of the bacterial adhesion, a strain 41452/01 of the oral commensal Streptococcus sanguis and a wild strain of Staphylococcus aureus were grown with and without sucrose supplementation for 6 days. Osmiumtetraoxyde (OsO4), uranyl acetate (UA), ruthenium red (RR), cupromeronic blue (CB) staining with critical electrolytic concentrations (CECs), and the tannic acid-metal salt technique (TAMST) were applied for electron microscopy. Cytochemically, only RR-positive fimbriae in S. sanguis were visualized. By contrast, some types of fimbriae staining were observed in S. aureus glycocalyx: RR-positive, OsO4-positive, tannophilic and CB-positive with ceasing point at 0.3 M MgCl2. The CB staining with CEC, used for the first time for visualization of glycoproteins of bacterial glycocalyx, also reveals intacellular CB-positive substances-probably the monomeric molecules, that is, subunits forming the fimbriae via extracellular assembly. Thus, glycosylated components of the biofilm matrix can be reliably related to single cells. The visualization of intracellular components by CB with CEC enables clear distinction between S. aureus and other bacteria, which do not produce CB-positive substances. The small quantities of tannophilic substances found in S. aureus makes the use of TAMST for the same purpose difficult. The present work protocol enables, for the first time, a partial cytochemical differentiation of the bacterial glycocalyx.

In vitro anti‐adhesive activity of green tea extract against pathogen adhesion

“…The anti-adhesive activities of the tea extracts demonstrated significantly more potent activities against the pathogens and became less effective against beneficial cell surface carbohydrates that mediate pathogen-cell interactions have been discovered (Sharon, 2006). In particular, the Lewis b blood group carbohydrate antigen has been demonstrated to mediate the adherence of H. pylori to human gastric mucosa, and the formation of biofilm from the fibrin fibers and glycocalyx is an important first step in the adhesion of S. aureus to the skin (Ilver et al, 1998;Krautgartner et al, 2005). The acidic polysaccharide CS-F2 inhibits the H. pylorimediated hemagglutination (0.12 μM), much higher than sialyllactose (ca.…”