Assessment of the safety and the anti-α-Gal immune response to an oral vaccine in captive-bred Humboldt penguins (Spheniscus humboldti)
Résumé
Oral administration of Escherichia coli O86:B7 expressing high levels of galactose-α-1,3galactose (α-Gal) was previously shown to protect turkeys from aspergillosis caused by Aspergillus fumigatus. In the present study, we first tested the basal level of anti-α-Gal antibodies (Abs) in healthy Humboldt penguin (Spheniscus humboldti) sera and penguin egg yolks. We then conducted a trial to test whether modulation of α-Gal immunity by oral administration of the probiotic bacterium Escherichia coli Nissle could prevent Humboldt penguins from aspergillosis. To this aim, E. coli Nissle was administered orally to ten penguins and a placebo was concomitantly given to a control group of ten other penguins. An aspergillosis diagnostic panel (CT scans, capillary zone electrophoresis, 3-hydroxybutyrate levels, anti-A. fumigatus Abs measurements) was implemented before, during and after the interventional procedure in both penguin groups. As results, healthy penguins produced natural anti-α-Gal Abs that were also detected in the egg yolks. Surprisingly, oral administration of E. coli Nissle was associated with lower levels of anti-α-Gal and anti-A. fumigatus Abs compared with the control group. Still, a correlation was seen between anti-E.coli Abs (IgM/IgY) and anti-α-Gal Abs (IgM/IgY), only in the vaccinated penguins. E. coli Nissle is a safe probiotic to use in Humboldt penguins with potential protective effect against aspergillosis to be further tested.
Origine : Fichiers produits par l'(les) auteur(s)