Extraction and Titration of Leukotoxins from Fusobacterium necrophorum Isolates Recovered from Bovine Liver Abscesses in Sulaimaniyah Region Suha Ali Hussein1 and Essam F. Al-Jumaily2

Abstract

This study was conducted to extract and titrate the leukotoxin of Fusobacterium
necrophorum isolates recovered from 75abscesses found in 24 livers of slaughtered cattle in
Sulaimaniyah region. The culture supernatants of these isolates were subjected to the
tetrazolium dye reduction test which revealed that the leukotoxin titer values of 34 F.
necrophorum subsp. necrophorum isolates ranged from 128 to 1024 (with a leukotoxin titer
mean of 516±46), whereas the leukotoxin titer values of the 11 F. necrophorum subsp.
funduliforme isolates ranged from 0 to 128 (with a leukotoxin titer mean of 73±12).