1.Nematode control failure due to anthelmintic resistance in a sheep farm in Malaysia: First identification of the F200Y mutation in the isotype 1 β-tubulin gene
Khadijah, S. ; Wahaf, A.N.S. ; Syahmi, M.I. ; Tan, T.K. ; Low, V.L. ; Azrul, L.M. ; Chong, J.L ; Lim, Y.A.L ; Abdullah, C.I.
Tropical Biomedicine 2018;35(4):999-1006
This paper reports total nematode anthelmintic resistance towards albendazole,
fenbendazole, levamisole and ivermectin in a commercial sheep farm located in Terengganu,
Malaysia. Faecal Egg Count Reduction Test (FECRT) was conducted on 25 sheep, where
five sheep in each group were treated with the respective four anthelmintics based on live
bodyweight. The balance of five sheep placed in the control group were not treated with
any anthelmintics. At day 13 post-treatment, faecal egg count was conducted and nematode
worm egg count reduction percentage was calculated to determine the resistance status
towards the respective anthelmintics tested. Results showed that nematodes were resistant
to all the anthelmintics tested, namely albendazole, fenbendazole, levamisole and ivermectin
with reduction percentage of 87%, 46%, 94% and 68%, respectively. Subsequently, the third
stage larvae of Haemonchus contortus and Trichostrongylus colubriformis recovered
from post-treatment faecal cultures were subjected to allele-specific polymerase chain
reaction (AS-PCR) assay to determine the presence of the benzimidazole resistance gene.
This study reports the occurrence of the classical F200Y mutation in the isotype 1 β-
tubulin gene, for the first time in Malaysia.