Passive immunoprophylaxis of edema disease in weaned pigs

August 1, 2005 —  Adam Moeser (ed. MontseTorremorell)
  [ES]

The objective of this study was to determine if parentally administered antitoxin serum against Stx2e (shiga toxin 2e) was protective against E. coli edema disease. Antitoxic serum was derived from slaughter pigs vaccinated repeatedly with Stx2e vaccine toxoid. The cytotoxic dose (CD50) and titer of neutralizing antibodies in serum was determined using the Vero cell assay. To determine the dynamics of the Stx2e neutralizing antibodies in the sera, 73 post-weaned pigs (10-18 kg, 3 days post-weaning) with no clinical signs of disease were administered 3 ml of antitoxic sera (with titers ranging between 8,000 and 32,000) subcutaneously. Serum administration induced significant increases in serum neutralizing antibody titers in weaned pigs (range = 16 to 512) when measured at 24 hours post-injection. Despite the high variability in titer responses in pigs, serum antibody titers of antitoxic sera were positively correlated with serum titers in piglets. Antibody titers of 8 or higher were observed in all piglets 14 days post-injection. Passively acquired antibodies disappeared between weeks 4 and 8 after serum administration in most piglets. To determine the protective dose of serum antibodies to Stx2e,recently-weaned pigs (7-9 kg) were injected in the knee fold with varying doses of porcine antitoxic sera (0.05 ml to 3 mL) with an antibody titer to St2xe of 130,000. The remaining pigs received porcine serum containing no antibodies to Stx2e serving as the control. Pigs were injected on the following day with 3 ml of culture supernatant of a shiga-toxigenic E. coli with a Stx2e titer of 150, 000 in the opposite knee fold. Administration of 0.2 to 3 ml of porcine immune serum protected pigs against Stx2e infection whereas piglets receiving 0.05 ml or less of antitoxic serum experienced severe clinical signs of edema disease following Stx2e injection that were observed within 18 hours of Stxe2 injection.

Reference:

Alexa P, Hamrik J, Stourakova K, Konstantinova L, Salajka. Passive immunoprophylaxis of edema disease in weaned pigs. Vet Med. - Czech. 49:447-452, 2004.