E.-G. Hoffmann

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Lipoteichoic acid (LTA) is a component of nearly all gram-positive membranes and recently has been found to be excreted into growth media by certain lactic acid bacteria. Cell-free extracts of LTA are usually contaminated with proteins, polysaccharides, and nucleic acids, thus causing problems to investigators studying the true biological function(s) of(More)
It was shown in this study that complement-resistant Brucella abortus used were unable to activate complement in the absence of specific antibody. Complement-resistant isolates possessed O-antigen, but complement-sensitive organisms used are O-antigen deficient. Since B. abortus LPS does not activate the alternative pathway of complement, we concluded that(More)
DNA sequence analysis showed that pyruvate decarboxylase (one of the most abundant proteins in Zymomonas mobilis) contains 559 amino acids. The promoter for the gene encoding pyruvate decarboxylase was not recognized by Escherichia coli, although the cloned gene was expressed at relatively high levels under the control of alternative promoters. The promoter(More)
The ability of serum complement to kill bacteria has been linked to host resistance to Gram-negative bacteria. A mechanism for killing extracellular organisms during early invasion, following release from infected phagocytic cells, or during bacteremia would contribute to a host's ability to resist disease. In fact, the ability of serum complement to kill(More)
This research explored the possibility that a mechanism for the inhibition of C exists that is capable of restricting lysis of antibody-sensitized homologous E. The ability of C to lyse E from six species was compared by using a passive lysis system that employed E coated with B. abortus LPS and bovine antibodies specific for B. abortus. A system was(More)
The indirect hemolysis test (IHLT) for the diagnosis of brucellosis uses a lipopolysaccharide (LPS) antigen obtained by dimethyl sulfoxide extraction of Brucella abortus. We showed that a non-LPS antigen can be obtained as a by-product of the IHLT antigen preparation. The antigen was purified to homogeneity by a combination of gel-filtration chromatography(More)
OBJECTIVE To evaluate the ability of bovine complement to kill a variety of field isolates and laboratory strains of Brucella abortus. DESIGN The experimental approach was to determine the sensitivity of B abortus isolates to killing by bovine serum, and to document the role of complement in brucellacidal activity. SAMPLE POPULATION Six laboratory(More)
Bovine immunoglobulin preparations from normal serum and from sera containing antibodies against Brucella abortus interfered with the brucellacidal action of bovine serum, whereas unfractionated normal serum and antisera were not inhibitory. The inhibitory property of immunoglobulin appeared to be attributable to some anticomplementary property because it(More)