Effects of Fusobacterium necrophorum leukotoxin on rabbit peritoneal macrophages in vitro
Fales, W.H.; Warner, J.F.; Teresa, G.W.
American Journal of Veterinary Research 38(4): 491-495
1977
ISSN/ISBN: 0002-9645 PMID: 851282 Document Number: 119609
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.