Intra-species variability in ITS-1 sequences of Haemonchus contortus isolated from goats in West Bengal, India

This study evaluated the existence of different genotypes of Haemonchus contortus prevailing among goats in West Bengal, India. These parasites were isolated from the abomasum of goat intestine and the molecular characterization was performed by comparing variation of nucleotide sequences of the internal transcribed spacer 1 (ITS-1) gene region. Single-strand conformation polymorphism (SSCP) analysis of ITS-1 amplified product showed the presence of three distinct conformations both in male and female parasites. The sequence analysis of conformations showed two single nucleotide polymorphisms (SNP) in male parasites at nucleotide positions 106 and 107 and one SNP was detected in female parasites at nucleotide position 157. These nucleotide variations in different isolates did not alter the interior loop structure of the predicted secondary RNA, therefore we believe these variations may not be responsible for any evolutionary changes among conformations.