Molecular characterization of Fasciola gigantica in Delhi, India and its phylogenetic relation to the species from South Asian countries.

The aim of this study was to phylogenetically analyze Fasciola gigantica (F. gigantica) from mainland India and to reveal the expansion history of F. gigantica in the Indian subcontinent. We analyzed 40 Fasciola flukes that were collected from Delhi, in the Indian mainland, and identified them as F. gigantica by using nucleotide analyses of the nuclear phosphoenolpyruvate carboxykinase (pepck) and DNA polymerase delta (pold) genes. Based on the nucleotide sequence of mitochondrial NADH dehydrogenase subunit 1 (nad1) gene, the flukes had 18 haplotypes. The haplotypes were classified under haplogroup A, which is predominant in the F. gigantica of South Asia. The population genetics of haplogroup A revealed that Delhi population showed higher π value than eastern India population. These results suggest that F. gigantica of haplogroup A might have spread from the west to the east in India along with the artificial migration of the domestic Zebu cattle, Bos indicus.