Protective effects of a transgenic carrot vaccine on piglet diarrhea / 대한수의학회지

The study evaluated whether a transgenic carrot vaccine could induce a K88-specific immune response in sows and whether the resultant maternal antibody could protect piglets against enterotoxigenic Escherichia coli (ETEC) K88ac infection. Sows (n = 15) selected randomly from a farm in Korea were assigned to three groups (n = 5 per group: control [untreated]), group A (orally inoculated with a non-transgenic and transgenic carrot vaccines at 2 and 4 weeks ante partum, respectively), and group B (conventionally vaccinated according to the manufacturer's instructions). After 7 days of lactation, 5 piglets selected randomly from each group were challenged with 1 x 1010 colony forming units/mL ETEC K88ac. Group C had the lowest mean fecal consistency score on post-challenge days 1 and 7. Histiologically, On post-challenge day 7, group C showed an increased duodenum and ileum villus:crypt ratio, compared to group A in the duodenum, with group B displaying the highest ratio. Groups B and C had more increased villus width than group A in the jejunum. Group C displayed the greatest increase in villus width in the ileum. The colostrums and serum from groups B and C displayed higher concentrations of IgA and IgG against ETEC K88, compared to group A. Based on the results, it was concluded that the transgenic carrot vaccine in sow per oral may have an effect on preventing piglet diarrhea as good as commercial recombinant vaccine.

Actividad antibacteriana de lactoferrina bovina y lactoferrina porcina sobre Escherichia Coli K88+ / Antibacterial Activity of Bovine and Porcine Lactoferrins Against Escherichia coli K88+

Se comparó el efecto antibacteriano de las lactoferrinas (Lfs) bovina y porcina sobre Escherichia coli K88+ (E. coli K88+), uno de los principales agentes etiológicos de las diarreas en lechones en el hemisferio norte. Las Lfs se purificaron por cromatografía de intercambio iónico, confirmando su pureza por electroforesis en condiciones desnaturalizantes y reductoras (SDS-PAGE) en geles al 8% y por inmuno-detección con anticuerpos anti- lactoferrina. La actividad bacteriostática se probó utilizando concentraciones de 0,5 y 1,0 mg/mL de Holo (saturada de hierro) y Apo-Lf (libre de hierro). En todos los casos la actividad bacteriostática de las Holo-Lfs fue insignificante, mientras que en ambas concentraciones, la Apo-Lf bovina mostró un mayor efecto en la inhibición del crecimiento de la E. coli K88+ que la Apo-Lf porcina. La actividad bactericida se ensayó utilizando concentraciones de 2,0; 4,0; 6,0 y 8,0 mg/mL de Lfs bovina o porcina. La Lf bovina mostró efecto bactericida a una concentración de 8 mg/mL, mientras que la Lf porcina no presentó este efecto. Los resultados indican que la fuente bovina puede ser útil en la prevención de diarreas en lechones.

The antibacterial effect of bovine lactoferrin (Lf) towards Escherichia coli K88+ (E. coli K88+) was compared with that of porcine Lf. E. coli K88+ is one of the main etiological agents of piglet diarrhea in the northern hemisphere. Lactoferrins (Lfs) were purified by ion exchange chromatography and further analyzed by electrophoresis using 8% sodium dodecyl sulfate polyacrylamide gel (SDS-PAGE) and immuno detection with anti-lactoferrin antibodies. Bacteriostatic effect was assayed using 0.5 and 1.0 mg/mL of Holo-Lf (iron saturated) or Apo-Lf (iron free). In all test the holo-LFs showed negligible bacteriostatic activity while for Apo-Lfs the bovine protein had the highest activity. Bactericide activity was assayed using bovine or porcine Lf concentrations of 2.0, 4.0, 6.0 y 8.0 mg/mL. Bovine Lf had bactericide activity at 8.0 mg/mL while no growth inhibition was observed with porcine Lf. These results suggest that bovine Lf may serve in the prophylaxis of piglets’ diarrhea.