Molecular characterisation of hybrid Fasciola from central Vietnam

Sequencing revealed recombination within hybrid ITS regions; reducing the frequency of heterozygous bases and underlining their limited value for identification purposes. Phylogenetic analysis of mitochondrial NAD1 and COX1 markers revealed high diversity and geneflow of F. gigantica within Vietnam and its surrounding nations; having nine and four haplotypes, respectively. Meanwhile, hybrids showed uniformity with all mtDNA sequences grouping within the parthenogenetic hybrid ‘Fg-C2’ haplogroup that dominates Southeast Asia, indicating they were likely imported into Vietnam via infected livestock.

Finally, the use of MALDI-ToF mass spectrometry as a high-throughput molecular identification tool for Fasciola spp. was explored. Here, representative spectral profiles of flukes from six different Fasciola spp. populations were obtained that could distinguish between them. Whilst reproducibility and statistical analyses revealed their suitability for automated detection, overlaps in PCA/PLS-DA, limited resolution for infra-populations and lack of reference databases limit its immediate implementation for Fasciola spp. identification. <br><br><i>Thesis is embargoed until 31 July 2028.</i>