Protection of calves against fatal enteric colibacillosis by orally administered Escherichia coli K99-specific monoclonal antibody

Abstract

A monoclonal antibody (MCA) to enterotoxigenic Escherichia coli K99 antigen agglutinated K99+ enterotoxigenic E. coli strains B44 (09:K30;K99;F41:H-) and B41 (0101:K99;F41:H-) grown at 37°C but not at 18°C. The MCA, which was characterized as immunoglobulin G1, reacted specifically with K99 antigen in an enzyme-linked immunosorbent assay and precipitated radiolabeled K99 antigen. A total of 45 colostrum-fed and colostrum-deprived calves were used in three separate trials to determine whether the orally administered K99-specific MCA would prevent diarrhea caused by strain B44. Twenty-eight calves were fed 1 ml of mouse ascitic fluid containing K99-specific MCA at 10 h of age and were orally challenged with strain B44 at 12 to 14 h of age. Control calves either received no placebo or were fed 1 ml of mouse ascitic fluid containing fibronectin-specific MCA at 10 h of age. There was no difference in the incidence of diarrhea between the two groups after challenge. However, the severity of diarrhea, as evaluated by the proportion of calves in each group that developed severe dehydration, the degree of clinical dehydration, the degree of clinical depression, the degree of weight loss, and the duration of diarrhea after challenge was significantly reduced in calves that received the K99-specific MCA. The mortality rate was also significantly lower (P < 0.001) in the treated (29%) than in the control (82%) group. These results suggest that orally administered K99-specific MCA can prevent severe fatal enteric colibacillosis.

Passive immunisation, an old idea revisited: Basic principles and application to modern animal production systems

“…E.g. colostrum replacers contain IgG purified from colostrum or plasma in addition to other proteins, fat, vitamins and minerals and provide 100-150 g IgG per 1.5-2 l dose (Jones and Heinrichs, 2005) and colostrum replacers can thus prevent FPT. In an experimental setting, Sherman et al administered ascites fluid containing monoclonal antibodies against K99 bacterial antigen orally to calves before oral challenge with ETEC O9:K30:K99:F34; 82% of the untreated control calves died in comparison to only 29% of the passively immunised calves (Sherman et al, 1983). This demonstrates proof-of-principle for passive immunisation mediated protection against this E. coli infection; however monoclonal antibodies are not generally available or applicable for passive immunisation of production animals as they are prohibitively expensive.…”

Bovine Enteric Colibacillosis

“…Furthermore the severity of clinical disease was also significantly reduced in calves receiving oral K99 specific M CA. 68…”

Bovine monoclonal antibodies to the F5 (K99) pilus antigen of E. coli, produced by murine/bovine hybridomas

“…Preventive and control measures to date including treatment with antibiotics (Kistwaria, Misra and Choudhuri, 1982) and maternal vaccination programmes (Acres, 1985) have met with varying success. Another treatment is to dose calves with antibodies to K99 pilus antigen, and a murine monoclonal anti-K99 antibody has been used for this purpose (Sherman, Acres, Sadowski, Springer, Bray, Raybould and Muscoplat, 1983).…”