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...

Vibrio harveyi VHH hemolysin is a putative pathogenicity factor in fish. In this study, the hemolysin gene vhhA was overexpressed in Escherichia coli, and the purified VHH was characterized with regard to pH and temperature profiles, phospholipase activity, cytotoxicity, pathogenicity to flounder, and the signal peptide.

We examined the properties of exotoxins produced by Aeromonas trota (A. enteropelogenes), one of the diarrheagenic species of Aeromonadaceae. Nine of 19 A. trota isolates that grew on solid media containing erythrocytes showed hemolytic activity. However, the hemolytic activities of the culture supernatants of these hemolytic strains of A. trota were markedly lower than those of A. sobria when ...

A hemolytic toxin related to thermostable direct hemolysin (TDH), TDH-related hemolysin (TRH), produced by Kanagawa-phenomenon-negative Vibrio parahaemolyticus is suspected of playing an important, but yet-to-be-elucidated role in diarrhea caused by this organism. In cultured human colonic epithelial cells, TRH increases Cl(-) secretion, followed by elevation of intracellular calcium.

Pigs infected with hemolytic F4(+) strains of enterotoxigenic Escherichia coli often develop septicemia secondary to intestinal infection. We tested the hypothesis that inactivation of hemolysin would reduce the ability of F4(+) enterotoxigenic E. coli to cause septicemia in swine following oral inoculation. Inactivation of the hemolysin structural gene (hlyA) did not decrease the incidence of ...

Background: Staphylococcus aureus spreads on soft agar surfaces, a phenomenon called “colony-spreading”. Results: We purified delta-hemolysin from S. aureus culture supernatant as an inhibitor of colony-spreading, and its disrupted mutant had high colony-spreading ability. Conclusion: S. aureus negatively regulates colony-spreading by secreting delta-hemolysin. Significance: This is the first e...

Lipide extracts of the red cells of several animal species have been analyzed chromatographically. Genetically determined differences in phospholipide composition were found. Lecithin is absent from the cells of ox, sheep, and goat. Cells containing lecithin are susceptible to the direct hemolysin of cobra venom while cells not containing lecithin are resistant. The facts indicate that the dire...

We determined the transcriptional start site of the thermostable direct hemolysin-related hemolysin gene (trh) of Vibrio parahaemolyticus by using a PCR-based method and identified the promoter. Mutagenic analysis indicated that the promoter-bearing region rather than its downstream inverted repeat sequence was responsible for the low-revel of trh transcription.