| 摘要 |
A method is provided for the enhanced elaboration of leukotoxin from F. necrophorum, and subsequent production of an inactivated leukotoxoid ruminant animal vaccine against F. necrophorum infection and consequent liver abscesses and/or foot rot in such animals. The method involves forming a culture of F. necrophorum bacteria in growth media, allowing the bacteria to grow therein and to simultaneously elaborate leukotoxin in a supernate; the culturing is preferably carried out at a temperature of from about 35-41 .degree.C, a pH of from about 6.5-8, and for a period of fr om about 4-9 hours. At the end of the culturing, bacterial growth and leukotoxin elaboration are terminated, preferably by separating t he leukotoxin supernate, whereupon the vaccine is produced by inactivation of at least the supernate.
|
