Purification and some properties of Aeromonas hydrophila hemolysin

Abstract

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 4.0 and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the hemolysin migrated as a single band, whereas electrophoresis at pH 9.4 and thin-layer isoelectric focusing demonstrated multiple bands. The results may indicate charge isomers of the hemolysin. The purified hemolysin had a hemolytic activity of 134 hemolytic units per microgram of protein on rabbit erythrocytes. It caused fluid accumulation in infant mouse intestines and rabbit ligated ileal loops. Purified hemolysin also elicited cytotoxicity to Vero cells and lethal toxicity to mice. All these biological activities were lost on heating for 5 min at 56 degrees C. These findings support the notion that A. hydrophila hemolysin is a cytotoxic enterotoxin.

The stress hormone norepinephrine increases the growth and virulence of Aeromonas hydrophila

“…Confer & Ayalew, 2012), aerolysins (Howard, Garland, Green, & Buckley, 1987), hemolysins (Asao, Kinoshita, Kozaki, Uemura, & Sakaguchi, 1984), enterotoxins (Chopra, Houston, Peterson, & Jin, 1993;Sha et al, 2005), serine protease (Cascón, Fregeneda, et al, 2000;Méndez et al, 2012), and elastase . Further, ahyR encodes a LuxR-type quorum sensing regulator that regulates the expression of virulence factors in A. hydrophila (Kirke, Swift, Lynch, & Williams, 2004;Swift et al, 1997Swift et al, , 1999.…”

Purification and characterization of a novel metalloprotease isolated from Aeromonas caviae

“…Crude cholera toxin at 5 lg ml À1 and sterile PBS were included as positive and negative controls, respectively. The cytotoxicity of the protease was assayed using Vero cell monolayer grown in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fecal calf serum by the method of Asao et al [19]. Cell was seeded in 96 well tissue culture plate at 10 4 cells per well.…”

Hemolysin of Aeromonas sobria stimulates production of cyclic AMP by cultured cells

“…The cytotoxic enterotoxin also possesses hemolytic activity in addition to its enterotoxic activity [6,8]. The cytotoxic enterotoxin lyses erythrocytes by the following mechanism.…”