Diagnosis of Benzimidazole Resistance in Haemonchus contortus of Sheep by Allele Specific PCR

J Tiwari,K M L Pathak,A P Kolte,S Kumar,D Singh,C P Swarnkar

doi:10.5713/ajas.2007.7

Abstract

The study was conducted on 162 adult male Haemonchus contortus of sheep collected from Avikanagar, Jaipur and Bikaner regions to diagnose the benzimidazole (BZ) resistance in H. contortus. The BZ resistance is primarily linked with the mutation in β-tubulin isotype 1 gene which substitute phenylalanine (Phe) into tyrosine (Tyr) at the 200 codon of the gene. An allele specific polymerase chain reaction (AS-PCR) technique was used for diagnosis of BZ resistance in H. contortus. In AS-PCR, one reverse primer (TGG 312) was used in two separate reactions with each of 2 forward primers (resistant TGG 331 and susceptible CAW 106 primer) that differed only at 3' nucleotide position. Therefore, the amplified products from resistant and susceptible parasites were produced 267 and 266 bp, respectively. A total of 162 parasites were genotyped, of which 130 parasites found homozygous resistant 'rr', 22 heterozygous 'rS' and 10 homozygous susceptible 'SS' type. The prevalence of 'rr' individuals was higher in Jaipur (98%) followed by Avikanagar (93%) and Bikaner (50%) regions. Overall, the prevalence of BZ resistant allele (r) was higher (87%) as compared to 13% of BZ susceptible allele (S).

Highlights

In India, Haemonchus contortus is one of the major parasite of sheep and goat, which causes production losses and even death in severe cases
BZ resistance, which is linked to the mutation at the 200 In India, the first occurrence of anthelmintic resistance codon of β-tubulin isotype 1 gene, was detected by allele in H. contortus of sheep was reported by Varshney and specific-PCR
Adult male H. contortus were genotyped for detection of mutation in the β-tubulin isotype 1 gene using Allele specific-PCR (AS-PCR) technique

Summary

Introduction

In India, Haemonchus contortus is one of the major parasite of sheep and goat, which causes production losses and even death in severe cases. BZ resistance, which is linked to the mutation at the 200 In India, the first occurrence of anthelmintic resistance codon of β-tubulin isotype 1 gene, was detected by allele in H. contortus of sheep was reported by Varshney and specific-PCR. The aim of the study was to (5’-G TAG AGA ACA CCG ATG AAA CAT A-3’) as use an allele specific-PCR for the detection of BZ resistance resistant primer.

Objectives

Results

Conclusion