Natural Pig Plasma Immunoglobulins Have Anti-Bacterial Effects: Potential for Use as Feed Supplement for Treatment of Intestinal Infections in Pigs

Hedegaard, Chris J.; Strube, Mikael L.; Hansen, Marie B.; Lindved, Bodil K.; Lihme, Allan; Boye, Mette; Heegaard, Peter M. H.

Syto24-stained bacteria were pre-incubated with various amounts of ppIgG (from 100 mg/ ml to 0.2 mg/ml, plus controls with no ppIgG) in a total volume of 50 μl for 30 min at 4°C. While the bacteria and immunoglobulins were incubating, the IPEC-J2 cells were placed for 30 min at 4°C; just before addition of pre-incubated bacteria, the IPEC-J2 cell culture medium was substituted with 50 μl 4°C adhesion buffer. Next, 50 μl bacteria in different swine immunoglobulin concentrations were added in parallel series to wells with or without IPEC-J2 cells; the latter wells served as non-adhesion controls. The plates were incubated for 180 min at 4°C. After adhesion, plates were washed three times in 100 μl adhesion buffer, and 100 μl adhesion buffer was added before reading fluorescence at 485/528 nm by means of Synergy HT (BioTek, Holm & Halby, Brøndby, Denmark) using Gen5 software (BioTek).