Identification of Leukotoxin and other vaccine candidate proteins in a Mannheimia haemolytica commercial antigen

Tucci, Paula; Estevez, Verónica; Becco, Lorena; Cabrera-Cabrera, Florencia; Grotiuz, Germán; Reolon, Eduardo; Marín, Mónica

M. haemolytica culture for vaccine antigen preparation was performed following the industrial standardized protocol. Culture media used was developed by Virbac Uruguay S.A. and is based on protein hydrolysates, yeast extract, dextrose, and sodium and potassium salts. The inoculum was prepared as previously described using 1 vial of production seed of M. haemolytica serotype A1 (production strain code B059). The production fermentor was inoculated with a 1:100 dilution of the inoculum and the culture was performed at 37°C with automatic agitation and aeration until the end of the logarithmic growth phase. After harvesting, culture was inactivated by incubation at 37°C with formaldehyde 0.5% (v/v) during 24 h. To obtain culture supernatant the inactivated culture was centrifuged at 8000×g for 30 min at 4°C. Inactivated culture supernatant was stored at −20°C.