Inhibition of verotoxin (VT) 2 absorption into systemic blood from intestine by repeated administration of bovine immune colostral antibody against VT2 in mice.

BACKGROUND/PURPOSE: Whether absorption of verotoxin (VT) 2 from the intestine in mice is inhibited by administration bovine immune colostral antibody against VT2 was investigated. METHODS: Three-week-old mice were administered VT2 solution at 477.8 ng/mL or 955.6 ng/mL, and bovine immune colostral antibody against VT2 was then administered three times. Whey without antibody against VT2 was administered to control mice. Serum levels of VT2 were measured by fluorescence enzyme immunoassay. RESULTS: Serum levels of VT2 in mice administered VT2 solution at 477.8 ng/mL and bovine immune colostral antibody against VT2 scarcely changed. By contrast, serum levels of VT2 in control mice increased and peaked 12 hours after administration. Peak values were 15.4 ± 5.04 ng/mL. Furthermore, serum levels of VT2 at 12 hours and 16 hours in control mice were significantly higher than in mice administered bovine colostral antibody against VT2. Serum levels of VT2 in mice administered antibody at 955.6 ng/mL showed no significant differences between repeated administration of bovine immune colostral antibody and controls. CONCLUSION: These results suggest that absorption of VT2 from the intestine was inhibited by repeated administration of bovine immune colostral antibody against VT2 at early stages of Escherichia coli O157:H7 infection, whereas VT2 in the intestine remained at low levels.

Human serum amyloid P component protects against Escherichia coli O157:H7 Shiga toxin 2 in vivo: therapeutic implications for hemolytic-uremic syndrome.

Shiga toxin (Stx) 2 causes hemolytic-uremic syndrome (HUS), an intractable and often fatal complication of enterohemorrhagic Escherichia coli O157:H7 infection. Here, we show that serum amyloid P component (SAP), a normal human plasma protein, specifically protects mice against the lethal toxicity of Stx2, both when injected into wild-type mice and when expressed transgenically; in the presence of human SAP, there was greatly reduced in vivo localization of Stx2 to the kidneys, suggesting a possible mechanism of protection. In humans, circulating SAP concentrations did not differ between patients with suspected enterohemorrhagic E. coli infection with antibodies to E. coli O157:H7 lipopolysaccharide and those without antibodies or between patients with HUS and those without it. However, the potent protection conferred by human SAP in the mouse model suggests that infusion of supplemental SAP may be a useful novel therapeutic approach to the treatment of this devastating condition.