El Tor and non-O1 strains of Vibrio cholerae were analyzed to determine whether synthesis of secreted hemolysin was influenced by the concentration of iron in the medium. Synthesis of hemolysin was found to be iron regulated in both El Tor and non-O1 isolates. Increased levels of hemolytic activity were detected in supernatants of iron-starved cells. Spontaneous hemolysin-deficient mutants of o...

Skalka B.: Antagonistic Effect of Staphylococcus hyicus and Staphylococcus chromogenes Exhibited on Staphylococcal Delta Hemolysin. Acta vet. Bmo, 60,1991: 61-69. Staphylococcus hyicus and Staphylococcus chromo genes are able to inhibit hemolytic effect of the staphylococcal delta hemolysin on agar media supplemented with human or sheep erythrocytes. This inhibition takes place even when the ef...

A thermolabile direct hemolysin from an El Tor cholera vibrio strain has been isolated and partially characterized as a simple protein of ca. 20,000 molecular weight. In addition to its hemolytic activity, the hemolysin is cytotoxic, cardiotoxic, and rapidly lethal. In these respects it resembles the thermostable direct hemolysin/cytotoxin/cardiotoxin/lethal toxin of Vibrio parahaemolyticus and...

To gain further evidence for the role of the Escherichia coli alpha-hemolysin in pathogenesis, its in vitro effects on human peripheral leukocyte function were studied. Leukocytes exposed to low doses of alpha-hemolysin responded with a marked chemiluminescence response, indicating activation of oxidative metabolism. This response was time and dose dependent. Pretreatment of leukocytes with dos...

Bacillus cereus causes distinct exotoxin-mediated diarrheal and emetic food poisoning syndromes and a variety of nongastrointestinal infections. Evidence is accumulating that hemolysin BL is a major B. cereus virulence factor. We describe two methods for detection of hemolysin BL in crude samples and on primary culture media. In the first method, the highly unusual discontinuous hemolysis patte...

To evaluate the pathogenicity of staphylococci from bovine raw milk, the general characteristics of 775 strains isolated from 798 samples of milk were studied. The coagulase test was performed by use of rabbit plasma. Chromogenesis, mannitol fermentation, and gelatin liquefaction were investigated on Chapman's Medium 110, after 48 hr of incubation. Production of beta-hemolysin, which has been c...

Some properties of eight strains of Newcastle disease virus (cell-fusing ability, hemolysin, heat stability of hemagglutinin or of hemolysin) do not correlate with virulence of these strains.

The Staphylococcus aureus toxin, α-hemolysin, is an important and well-studied virulence factor in staphylococcal infection. It is a soluble monomeric protein that, once secreted by the bacterium, forms a heptameric pore in the membrane of a broad range of host cell types. Hemolysin was recently discovered to bind and activate a disintegrin and metalloprotease 10 (ADAM10). In epithelial and end...

Although Pseudomonas aeruginosa has been known to produce hemolysis on blood agar plates, attempts to obtain hemolysin in broth culture filtrates of this organism have been generally unsuccessful. Bullock and Hunter (1900) noted that filtrates of 3 to 4 week old broth cultures of this organism lysed suspensions of erythrocytes of several animal species, including man. This finding was confirmed...

Davie, Joseph M. (Indiana University, Bloomington), and Thomas D. Brock. Action of streptolysin S, the group D hemolysin, and phospholipase C on whole cells and spheroplasts. J. Bacteriol. 91:595-600. 1966.-The effect of streptolysin S, the group D hemolysin, and phospholipase C (the alpha toxin of Clostridium perfringens) on whole cells and spheroplasts or protoplasts of three strains of strep...