Sensitive PCR for detecting Benzimidazole resistant sub populations
of ovine nematodes in the Waikato
S. Lehrer, H. Davey, T. Watson, R.J. Wilkins
Israel Institute for Biological Research, PO Box 19, Ness-Ziona, Israel
Proceedings of the New Zealand Society of Animal Production. 1995,
55: 209-210
Repeated sheep treatment with the anthelmintic drug benzimidazole
(BZ) resulted in selection of genetically benzimidazole-resistant (BZ-R)
nematodes, which code for a specific allele of isotype 1Beta-tubulin. The
presence of this allele was tested in the Waikato ovine nematode, using an
allele specific PCR. Two isotype allele specific oligomers for O.
circumcincta (O.c.) Beta-tubulin gene were designed. The last
base at the 3í end of each primer, corresponding to amino acid 200, confers
the specificity. PCR with those 2 upstream primers, in combination with a
common downstream primer at the reverse side, distinguished between BZ-R
and BZ-sensitive O.c. nematodes. To detect <1% resistant
O.c. subpopulations which are undetectable with allel specific PCR,
Amplification Created Restriction Site (ACRS) PCR was developed. An
upstream primer was designed which is cleavable by the restriction enzyme
Sca 1 in resistant but not sensitive O.c.. The test using
individual larva DNA proves this approach is potentially sensitive for
widespread use under field conditions.
Keywords: NZSAPAB;
Benzimidazole; Betal-tubulin; O. circumcincta; benzimidalole
resistance, allele specific PCR
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Last Updated 25-01-1997
