Isolation and characterisation of four distinct cytotoxic factors of Salmonella Weltevreden.

摘要: Four distinct cytotoxins with different biological, physico-chemical and antigenic characteristics were isolated from a single Salmonella Weltevreden strain recovered buffalo meat. The toxins purified by means of salt precipitation, dialysis, gel filtration ion-exchange chromatographic methods. Cytotoxin I was dermonecrotic, verocytotoxic lethal for the mouse (LD50 120 micrograms). It induced accumulation serosanguinous fluid in rabbit ligated ileal loop (RLIL) mucinous stomach. active within narrow pH range (5.0-8.0) lost its activity on autoclaving 1 min. II verocytotoxic, enterotoxic to (LD50, mg). delayed vasopermeability skin, at between 5.6 8.4 only heat-sensitive (100 degrees C, 30 min). III neither dermatotoxic nor enterotoxic. vacuolation, multinucleation formation syncytia Vero cells. pH-sensitive beyond 4.8 8.2. completely inactivated boiling IV intensely necrotizing skin 6 h inoculation lysed also possessed haemolytic lecithinase/phospholipase-C activities. cytotoxin heating 90 C (30 min) but remained 2.5 7.5. PIs estimated be 9.0, 7.0, 3.0, respectively. All four immunogenic rabbits antigenically unrelated as anticytotoxin neutralized homologous did not cross-react heterologous cytotoxins.