title: Effects of Fusobacterium necrophorum leukotoxin on rabbit peritoneal macrophages in vitro.
abstract: A method to demonstrate leukotoxic activity of Fusobacterium necrophorum in vitro is described. Continuous dialysis sac culture system, using reduced liquid medium was used to grow F necrophorum for 7-day periods. The continuous culture dialysis filtrate contained leukotoxic substance(s) which appeared to be less than 10,000 in molecular weight, heat resistant, and stable at 4 C for at least 10 days. Leukotoxic activity was demonstrated in vitro by determining the percentage of macrophages taking up trypan blue dye after these were exposed to a 1:2 solution of continuous culture dialysis filtrate and Eagle's minimal essential medium at 1, 2, 4, and 6 hours. Approximately 90% of these macrophages were destroyed during the 6-hour incubation period.
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000302:isolation & purification / Q000494:pharmacology*; D002478:Cells, Cultured; D003470:Culture Media; D003956:Dialysis; D005673:Fusobacterium / Q000032:analysis / Q000254:growth & development; D008264:Macrophages / Q000187:drug effects*; D008970:Molecular Weight; D011817:Rabbits; D014462:Ultrafiltration
chemical_list: D001427:Bacterial Toxins; D003470:Culture Media