First morphogenetic analysis of parasite eggs from Schistosomiasis haematobium infected sub-Saharan migrants in Spain and proposal for a new standardised study methodology

Abstract

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Geographical Influence on Morphometric Variability of Genetically “Pure” Schistosoma haematobium Eggs from Sub-Saharan Migrants in Spain

“…For mitochondrial cox 1 profiling, an RD-PCR of each of the 162 eggs was performed using one universal forward (5′-TTTTTTGGTCATCCTGAGGTGTAT-3′) and three reverse species-specific primers (5′-CACAGGATCAGACAAACGAGTACC-3′, 5′-TGCAGATAAAGCCACCCCTGTG-3′ and 5′-TGATAATCAATGACCCTGCAATAA-3′) [ 26 , 27 , 28 ] to amplify a specific mtDNA cox 1 region (differing in length) for S. bovis (306 bp), S. mansoni (375 bp) and S. haematobium (543 bp). The PCR reactions were carried out in a final volume of 12.6 μL, comprising 8 μL of DNA template, 2.5 μL of 5X Colorless GoTaq Flexi Buffer, 0.75 μL of MgCl 2 (25 mM), 0.25 μL of dNTP (10 mM), 1 μL of primer mix (1 μM), 0.1 μL of GoTaq G2 Hot Start Polymerase (Promega, Madison, WI, USA) and using PCR conditions as previously described [ 23 ]. The amplified products were separated electrophoretically on a 2.5% agarose gel containing GelRed (Biotium, San Francisco, CA, USA).…”

“…The information provided by the maternally inherited mtDNA profiling was complemented with the partial sequence of the 5.8S rRNA gene and the complete ITS-2 of the rDNA. PCR amplification and sequencing were performed independently on each of the 162 eggs using primers 3S and A28S [ 23 , 29 , 30 , 31 ], designed in the flaking regions of the 5.8S and 28S rRNA genes. PCR conditions were an activation step of 4 min at 94 °C, followed by 32 cycles of 55 secs at 94 °C, 1 min at 55–62 °C and 1.30 min at 72 °C with a final extension of 5 min at 72 °C followed by a final cooling at 4 °C.…”

“…Molecular data are particularly relevant in the case of human schistosome eggs excreted in urine to identify pure or hybrid species, as both present a typical terminal spur morphology. Regarding morphologic characterization, a standardized methodology able to provide morphological data complementary to molecular data has been proposed [ 23 ]. Furthermore, these new morphometric concepts offer a suitable method to morphologically characterize the phenotype of Schistosoma eggs in order to assess the influence of different factors on the shape and size of parasite eggs, such as the geographical origin of the parasite.…”

Variability ofCalodium hepaticumeggs from sigmodontine host species through geometric morphometric analysis

“…The PCA, CVA and Mahalanobis distances were performed using both the Collecting Landmarks for Identification and Characterization package and the available online XYOM software (https://xyom.io/) and tested by non-parametric permutation tests with 1000 iterations each. Values were considered statistically significant when P < 0.05 (Dujardin & Dujardin, 2019;García-Sánchez et al, 2019;Reguera-Gomez et al, 2021). Nevertheless, to avoid matrix singularities, some measurements were discarded because of their partial overlap with other measurements.…”

“…For this reason, new tools should be applied to advance in diagnostics. Furthermore, morphological analyses are necessary to complement molecular techniques (Valero et al, 2001(Valero et al, , 2009(Valero et al, , 2012García-Sánchez et al, 2019Reguera-Gomez et al, 2021).…”