Enterohemolysin produced by Escherichia coli associated with infant diarrhea showed characteristics similar to those of thiol-activated hemolysins produced by Gram-positive bacteria, including inactivation by cholesterol, lytic activity towards eukaryotic cells and thermoinstability. However, enterohemolysin activity was not inactivated by oxidation or by SH group-blocking agents (1 mM HgCl2, 1...

More than 90% of the Plesiomonas shigelloides strains that we tested produced a beta-hemolysin, as judged by the results of agar overlay and contact-dependent hemolysis assays. The hemolysin was cell associated, was active against the erythrocytes of various animal species, and was synthesized at both 25 and 35 degrees C. Activity was lost after thermal or proteolytic treatments or after preinc...

A Vibrio cholerae cytotoxin, designated VcVac, was found to cause vacuolation in Vero cells. It was originally detected in the pathogenic O1 Amazonia variant of V. cholerae and later shown to be produced in environmental strains and some El Tor strains. Comparison of VcVac production in various strains suggested that hemolysin was responsible for the vacuolating phenotype. Genetic experiments e...

Three classes of immunologically reactive cells, differing only slightly in size from each other, are required for the production of hemolysin-forming cells in culture. The three classes of cells can be detected in the normal mouse spleen by the combined use of rosette formation, velocity sedimentation, and irradiation. One class of cells (peak sedimentation velocity, 3.2 mm per hr) forms roset...

We previously reported the occurrence of Vibrio parahaemolyticus in patients and the environment in the Pacific Northwest. The present studies compare the biochemical characteristics, Kanagawa hemolysin reactions, and plasmid profiles of 13 patient and 221 environmental isolates of the organism. Classical biochemical testing of the isolates revealed similar reactions for the clinical and enviro...

Post-antifungal effect (PAFE) of Candida and its production of hemolysin are determinants of candidal pathogenicity. Candida albicans is the foremost aetiological agent of oral candidosis, which can be treated with polyene, azole, and echinocandin antifungals. However, once administered, the intraoral concentrations of these drugs tend to be subtherapeutic and transient due to the diluent effec...

Extra- and intracellular Escherichia coli hemolysin expressed by two cloned hly determinants, both under the control of the activator element hlyR, were analyzed. One determinant carried all four hly genes (hlyC, hlyA, hlyB, and hlyD), whereas the other carried only the two genes (hlyC and hlyA) required for synthesis of active hemolysin but not those essential for its secretion. It was shown t...

Group B Streptococcus (GBS) is the leading cause of severe bacterial infections in human newborn infants. Advances in streptococcal molecular genetics and refinement of in vitro and in vivo model systems of GBS disease have led to the discovery and characterization of several extracellular virulence factors elaborated by this pathogen. This review summarizes our current understanding of GBS ext...