Abstract:
Kikuyu poisoning occurs sporadically in South Africa. It is of major economic importance,
as valuable dairy cows are often poisoned by it, and once affected, the mortality rate is high.
Pennisetum clandestinum samples were collected during eight outbreaks of kikuyu poisoning
in cattle in the Eastern Cape Province of South Africa from 2008 to 2010. The kikuyu grass
samples were submitted specifically for the isolation and molecular identification of Fusarium
species, as it was recently suggested that mycotoxins synthesised by Fusarium torulosum
could be the cause of this intoxication. Ninety-four Fusarium isolates were retrieved from
the grass samples, of which 72 were members of the Fusarium incarnatum/Fusarium equiseti
species complex based on morphology and phylogenetic analyses of the translation elongation
factor 1α sequence data. The South African isolates from kikuyu identified as members of the
F. incarnatum/F. equiseti species complex grouped together in six separate clades. The other
isolates were Fusarium culmorum (n = 3), Fusarium redolens (n = 4) and Fusarium oxysporum
(n = 15). Although F. torulosum could not be isolated from P. clandestinum collected during
kikuyu poisoning outbreaks in South Africa, the mycotoxicosis theory is still highly plausible.
