Summary. An elastase of Staphylococcus epidermidis was purified by ion exchange chromatography on CM-Sepharose and characterised. Its M, is c. 21 kDa, its optimal temperature for activity is 42OC and the pH optimum is 6.8. The enzyme is activated by cysteine and other SH-donators and inhibited by ~-trans-epoxy-succinylleucylamido-(4-guanidin0)butane (E64), an inhibitor of cysteine proteases, but not by 3,4-dichloroisocoumarin (3,4-DCI), an inhibitor of serine proteases. This finding suggests that the elastase of S. epidermidis is a cysteine protease. Because S. epidermidis elastase degrades human sIgA, IgM, serum albumin, fibrinogen, and fibronectin, this enzyme may be regarded as a virulence factor.

Adherence to biomaterials and production of biofilm is thought to be pivotal in the pathogenesis of prosthetic device infection by Staphylococcus epidermidis. In this study a strong association (P < .001) of hemagglutination with adherence and biofilm production was observed. Hemagglutination was not associated with cell surface hydrophobicity (P = .906). Hemagglutination inhibition studies revealed that hemagglutination was not affected by heat, pH, cation concentration, proteolytic enzymes, biologic detergent, serum proteins, or subinhibitory antibiotics. Hemagglutination was abolished by periodate oxidation and digestion with glycosidases. It was markedly inhibited by beta-lactose and its monosaccharide constituents in a concentration-dependent fashion. Hemagglutinin expression depended on the presence of glucose. Chemical analysis of a partially purified hemagglutinin preparation and cell-free hemagglutinating supernatants revealed little or no protein and small quantities of reducing sugars, pentose, ketose, hexosamine, uronic acid, and phosphate. Hemagglutinin of S. epidermidis appears to be a polysaccharide distinct from other known adhesins of S. epidermidis.

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Our results suggest that the Helicobacter pylori infection does not play a pathogenic role in stress ulcer bleeding. Prophylactic cure of Helicobacter pylori can not be recommended in this setting.