An improved procedure for the isolation and purification of the hemolysin produced by a group B streptococcus was developed, and the inactivation of partially purified hemolysin by several enzymes was studied. Hemolysin obtained in buffer containing starch and Tween 80 was inactivated by subtilisin and alpha-amylase, suggesting that the hemolysin may consist of a protein hemolytic moiety comple...

It is evident that there are numerous interacting factors which affect streptolysin in the presence of fermented sugars. The principal action is the change in the metabolism of the streptococcus by which more carbohydrate and less protein is utilized; although the growth is much increased there is proportionately less hemolysin. The acid developed in these cultures not only lessens the vitality...

Haemophilus ducreyi, the etiologic agent of chancroid, a genital ulcer disease, produces a cell-associated hemolysin whose role in virulence is not well defined. Hemolysin is encoded by two genes, hhdA and hhdB, which, based on their homology to Serratia marcescens shlA and shlB genes, are believed to encode the hemolysin structural protein and a protein required for secretion and modification ...

The halophilic bacterium Vibrio fluvialis is an enteric pathogen that produces an extracellular hemolysin. This hemolysin was purified to homogeneity by using sequential hydrophobic-interaction chromatography with phenyl-Sepharose CL-4B and gel filtration with Sephacryl S-200. It has a molecular weight of 63,000 and an isoelectric point of 4.6, and its hemolytic activity is sensitive to heat, p...

A vibrio isolated from the intestine of a coastal fish was identified as Vibrio hollisae by its biochemical characteristics. The isolate reacted with the gene probe for the thermostable direct hemolysin of Vibrio parahaemolyticus. The hemolysin produced by the isolate from the fish had traits identical to those of the thermostable direct hemolysin-like hemolysin produced by a clinical strain of...

The prevalence of 31 virulence factors was analyzed among nalidixic acid-susceptible and -resistant Escherichia coli strains from phylogenetic group B2. Hemolysin, cytotoxic necrotizing factor 1, and S and F1C fimbriae genes were less prevalent among nalidixic acid-resistant E. coli strains. Quinolone resistance may be associated with a decrease in the presence of some virulence factors.

Staphylococcus aureus (S. aureus) is a human commensal and an opportunistic pathogen that may affect the gastrointestinal tract, the heart, bones, skin or the respiratory tract. S. aureus is frequently involved in hospitalor community-acquired lung infections. The pathogenic potential is associated with its ability to secrete highly effective virulence factors. Among these, the pore-forming tox...

Enterococcus faecalis is a leading cause of infections in liver transplant patients. This study reviewed the incidence of virulence factors such as hemolysin, gelatinase, aggregation substances (asa1 and asa373), or the enterococcal surface protein (Esp) in isolates from liver transplant patients. In total, 133 isolates from liver transplant patients were compared with 47 isolates from feces of...

Haemophilus ducreyi, the causative agent of chancroid, produces a hemolysin, whose role in virulence is not well defined. To assess the possible role of hemolysin in pathogenesis, we evaluated its target cell range by using wild-type H. ducreyi 35000, nonhemolytic mutants with the hemolysin structural gene deleted, and isogenic strains expressing different amounts of hemolytic activity. The cyt...

Delta-hemolysin of coagulase-negative staphylococcal strains was immunologically identical to delta-hemolysin of Staphylococcus aureus (Newman) but distinct from delta-hemolysin from a canine strain of S. aureus.