fibrin and Impetigo

Glycocalyx collapses during dehydration to produce electron-dense accretions. Confocal laser scanning microscopy (CLSM) may be used to visualize fully hydrated microbial biofilms.. Using CLSM, to analyse glycocalyx production by Staphylococcus aureus cells in skin lesions of bullous impetigo, atopic dermatitis and pemphigus foliaceus. A second objective was to compare numbers of S. aureus cells in tissue sections prepared by different methods for routine light microscopy.. S. aureus cells in skin lesions of impetigo, atopic dermatitis and pemphigus were stained with safranin, and positive staining with fluorescein isothiocyanate-conjugated concanavalin A was considered to indicate the presence of glycocalyx.. All S. aureus cells tested in skin lesions of impetigo, atopic dermatitis and pemphigus were covered with glycocalyx and formed microcolonies. The numbers of S. aureus cells in a routine light microscopy section were significantly lower than those in a frozen section that had not been dehydrated with ethanol.. S. aureus cells generally produce glycocalyx in skin lesions of bullous impetigo, atopic dermatitis and pemphigus foliaceus, which accounts for the difficulty of removing S. aureus cells from these skin lesions. The glycocalyx may collapse during dehydration and most of the S. aureus cells may be carried away during preparation of routine light microscope sections.

Topics: Acetic Acid; Adolescent; Adult; Aged; Biofilms; Child; Child, Preschool; Colony Count, Microbial; Dermatitis, Atopic; Female; Fibrin; Fusidic Acid; Glycocalyx; Humans; Hydrochloric Acid; Impetigo; Male; Microscopy, Confocal; Middle Aged; Pemphigus; Staphylococcus aureus

The formation of membranous structure (thickness from the plastic tissue-culture coverslip (hematoxylin-eosin) > 1 mm; periodic acid-Schiff-positive) was more prominent with Staphylococcus aureus (S. aureus) strains isolated from impetigo (coagulase types I.V origin) than with S. aureus strains isolated from furuncle (coagulase type IV origin) (P < 0.05) in the plastic tissue-culture coverslip in human plasma after 72 h. Attachment of S. aureus cells to a plastic tissue-culture coverslip was more marked in 0-3% fibrinogen/tryptic soy broth (TSB) than in plasma (P < 0.05). The formation of the membranous structure was observed on the plastic tissue-culture coverslip with 0.3% fibrinogen/human serum but not with 0.3% fibrinogen + 5% glucose/TSB. Electron microscopy revealed abundant fibrin around S. aureus cells at 4 h and Ruthenium red-positive materials increased at 24 and 72 h in plasma. Staphylococcus aureus cell attachment to the plastic tissue-culture coverslip in plasma decreased by addition of levofloxacin (LVFX) at 1/2 minimum inhibitory concentration (MIC) and clarithromycin (CAM) at 1/4 MIC. Polysaccharide production of S. aureus cells on the plastic tissue-culture coverslip in plasma decreased with the addition of CAM at 1/4 MIC. Fibrinogen is closely related to initiation of infection but biofilm formation requires the conversion of fibrinogen to fibrin. Thus, attachment of S. aureus cells to the plastic tissue-culture coverslip, conversion of fibrinogen to fibrin by coagulase-prothrombin complex, and production of abundant glycocalyx by S. aureus cells are at least required for the production of biofilm in staphylococcal skin infection.

Topics: Anti-Bacterial Agents; Biofilms; Cell Membrane; Clarithromycin; Coagulase; Fibrin; Fibrinogen; Furunculosis; Humans; Impetigo; Microbial Sensitivity Tests; Microscopy, Electron; Polysaccharides; Staphylococcus aureus; Tryptophan