A synthetic medium capable of supporting growth of Vibrio parahaemolyticus is described. Growth yields and generation times were comparable to growth in a complex medium, although Kanagawa hemolysin was undetectable in the synthetic medium. Upon the addition of single amino acids to this synthetic medium, only D-tryptophan induced production of the hemolysin. L-Tryptophan was found to inhibit t...

Vibrio parahaemolyticus isolates derived from an outbreak of gastroenteritis in the Republic of Maldives did not have the genetic potential to produce the thermostable direct hemolysin, but one such isolate produced a hemolysin immunologically related to the thermostable direct hemolysin (T. Honda, Y. Ni, and T. Miwatani, Infect. Immun. 56:61-965, 1988). The Maldives isolates hybridized with th...

Four nucleotide sequences showing homology to known hemolysin genes were cloned and sequenced from V. anguillarum strain H775-3. The four genes, vah2, vah3, vah4 and vah5, have open reading frames encoding polypeptides of 291, 690, 200 and 585 amino acid residues, respectively, with predicted molecular masses of 33, 75, 22 and 66KDa, respectively. VAH2 is most closely related to a putative hemo...

Aeromonas hydrophila infection can cause mass mortality fish and result economic losses for farmers. These is bacterium secretes substances or compounds that support its virulence by producing toxins extracellular proteins in the form of enzymes. This study aimed to determine activity β-hemolysin toxin, DNase enzyme gelatinase A. isolated from catfish (Clarias batrachus) Sidoarjo. research was ...

OBJECTIVE Brazilian legislation has recently suggested the use of the qualitative hemolysin test instead of isohemagglutinin titers as prophylaxis for acute hemolysis related to plasma-incompatible platelet transfusions. The efficacy of this test in preventing hemolytic reactions has never been evaluated while isohemagglutinin titers have been extensively studied. The main objective of this stu...

A thermostable direct hemolysin was purified from culture filtrates of Vibrio parahaemolyticus. The purified hemolysin gave one precipitation line with the antihemolysin antiserum on agar-gel diffusion test and a single band on polyacrylamide gel electrophoresis. The hemolysin was not inactivated by heating at 70 to 100 C for 10 min. The hemolytic activity was not enhanced by the addition of le...

Escherichia coli isolates causing urinary tract infection in 83 male infants younger than 90 days with and without bacteremia were compared for phylogenetic groups and the presence of 10 virulence factors. Our result suggest that the absence of both hemolysin and antigen K1 may be used as a negative predictive factor for bacteremia.

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.

A hemolysin produced by a strain of Aeromonas hydrophila isolated from a patient with diarrhea was purified by acid precipitation and quarternary aminoethyl-Sephadex chromatography. The molecular weight of the hemolysin was estimated at 50,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and at 48,000 by Sephadex G-100 gel filtration. In polyacrylamide gel electrophoresis at pH ...

Porphyromonas gingivalis, a periodontal pathogen, has the ability to lyse erythrocytes. The hemolytic activity of P. gingivalis A7436 was purified as a 45-kDa protein from the culture supernatant of a 3-days old culture using nickel-nitrilotriacetic acid chromatography. Erythrocytes treated with purified P. gingivalis hemolysin showed the presence of pores and extracellular debris by scanning e...