Benzimidazole resistance in Teladorsagia circumcincta of goats

The present study describes the status of benzimidazole (BZ) resistance in Teladorsagia circumcincta of goats in Uttarakhand by egg hatch test (EHT) and by allele specific polymerase chain reaction (AS-PCR). The application of AS-PCR was done based on amino acid mutation at position 200 (F200Y) of beta-tubulin isotype-1. Adult worms were collected from slaughtered animals at different places of Uttarakhand from January 2017 to December 2019 and were identified morphologically. Results of EHT revealed susceptible populations of strongyles in Uttarakhand. AS-PCR of 139 adult worms revealed 0.72% homozygous resistant (rr), 97.12% homozygous susceptible (SS) and 2.16% heterozygous susceptible (rS) among different regions of Uttarakhand. The study revealed that the allele frequency was 1.8% and 98.2%, respectively for resistant (TAC, tyrosine) and susceptible (TTC, phenylalanine). Our findings indicate that the SNP F200Y is important for benzimidazole resistance in the studied populations and the status of BZ resistance in T. circumcincta is very low in all the parts of the state.