Open AccessIsolation and purification of Aeromonas sobria cytotonic enterotoxin and -haemolysin
Author(s) -
Peter Gosling,
P. C. B. Turnbull,
N. F. Lightfoot,
J. V. S. Pether,
Richard J. Lewis
Publication year - 1993
Publication title -
journal of medical microbiology/journal of medical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 117
eISSN - 1473-5644
pISSN - 0022-2615
DOI - 10.1099/00222615-38-3-227
Subject(s) - enterotoxin , toxin , hemolysin , lysis , microbiology and biotechnology , aeromonas , incubation , bacteria , biology , cholera toxin , chemistry , chromatography , hemolysis , biochemistry , escherichia coli , virulence , immunology , genetics , gene
Aeromonas sp., grown in tryptone soya broth supplemented with yeast extract, 0.6%, pH 7.5, and incubated with agitation at 100 oscillations/min for 15 h at 37 degrees C produced optimal amounts of beta-haemolysin and cytotonic enterotoxin. More prolonged incubation resulted in the loss of enterotoxic activity and anion exchange chromatographic analysis indicated the presence of a moiety capable of breaking down the toxin. Anion exchange fast protein liquid chromatography resulted in a single peak of haemolytic activity and two peaks with enterotoxic activity. The cytotonic enterotoxin was purified from the fraction most active in the infant mouse assay; the second peak, which did not cross-react immunologically, may represent a second cytotonic enterotoxin. Neither peak was observed in the chromatographic fractions of filtrates from strains devoid of activity in the infant mouse assay. Purified enterotoxin, estimated to have a mol. wt of 15 kDa by SDS-PAGE, caused fluid accumulation in the infant mouse assay, was non-haemolytic to rabbit erythrocytes, caused an increase in cAMP activity in tissue culture cells and did not cross-react immunologically with components of cholera toxin or the whole toxin. Purified beta-haemolysin had an estimated mol. wt of 55 kDa, lysed rabbit erythrocytes and did not cause fluid accumulation in the infant mouse test.