Fasciola hepaticaandFasciola giganticacoexistence in domestic ruminants in Nigeria: application of a PCR-based tool

摘要

The distinction betweenFasciola hepaticaandFasciola giganticahas been traditionally based on morphological criteria, although accurate recognition of the two flukes is usually difficult because of substantial variations in morphological features. The main aim of this study was to develop a PCR-based assay for discrimination between both species collected in sheep and cattle from Nigeria. A total of 47 animals, 33 cattle and 14 sheep, were sampled, and a single adult fluke was collected from each animal. DNA was extracted from flukes, and primers were designed based on mitochondrial DNA sequences to amplify a 304 bp fragment for the identification ofF. hepaticaand 752 bp forF. gigantica. PCR products from 12 flukes were sequenced for phylogenetic analysis. A total of 29 out of 47 flukes were identified asF. hepaticaand 18 asF. gigantica. Within each host, the percentage of each fluke species was as follows: In cattle, 18/33 (54.5%) and 15/33 (45.5%) wereF. hepaticaandF. gigantica, respectively. In sheep, 11/14 (78.6%) wereF. hepaticaand 3/14F. gigantica(21.4%). The phylogenetic analysis confirmed these results. Although the number of flukes collected in sheep was limited, it seems thatF. hepaticais more prevalent in sheep thanF. gigantica, whereas the percentage of each species was similar in cattle. This study confirms the presence ofF. hepaticain Nigeria.