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result(s) for
"De Elías-Escribano, Alejandra"
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DNA Multi-Marker Genotyping and CIAS Morphometric Phenotyping of Fasciola gigantica-Sized Flukes from Ecuador, with an Analysis of the Radix Absence in the New World and the Evolutionary Lymnaeid Snail Vector Filter
2021
Fascioliasis is a disease caused by Fasciola hepatica worldwide transmitted by lymnaeid snails mainly of the Galba/Fossaria group and F. gigantica restricted to parts of Africa and Asia and transmitted by Radix lymnaeids. Concern has recently risen regarding the high pathogenicity and human infection capacity of F. gigantica. Abnormally big-sized fasciolids were found infecting sheep in Ecuador, the only South American country where F. gigantica has been reported. Their phenotypic comparison with F. hepatica infecting sheep from Peru, Bolivia and Spain, and F. gigantica from Egypt and Vietnam demonstrated the Ecuadorian fasciolids to have size-linked parameters of F. gigantica. Genotyping of these big-sized fasciolids by rDNA ITS-2 and ITS-1 and mtDNA cox1 and nad1 and their comparison with other countries proved the big-sized fasciolids to belong to F. hepatica. Neither heterozygotic ITS position differentiated the two species, and no introgressed fragments and heteroplasmic positions in mtDNA were found. The haplotype diversity indicates introductions mainly from other South American countries, Europe and North America. Big-sized fasciolids from Ecuador and USA are considered to be consequences of F.gigantica introductions by past livestock importations. The vector specificity filter due to Radix absence should act as driving force in the evolution in such lineages.
Journal Article
Benzalkonium Chloride Significantly Improves Environmental DNA Detection from Schistosomiasis Snail Vectors in Freshwater Samples
by
Sánchez-Marqués, Raquel
,
Cuervo, Pablo Fernando
,
Bargues, Maria Dolores
in
Analysis
,
benzalkonium chloride
,
Bulinus truncatus survey and surveillance
2025
Urogenital schistosomiasis, caused by Schistosoma haematobium and transmitted by Bulinus snails, affects approximately 190 million individuals globally and remains a major public health concern. Effective surveillance of snail vectors is critical for disease control, but traditional identification methods are time-intensive and require specialized expertise. Environmental DNA (eDNA) detection using qPCR has emerged as a promising alternative for large-scale vector surveillance. To prevent eDNA degradation, benzalkonium chloride (BAC) has been proposed as a preservative, though its efficacy with schistosomiasis snail vectors has not been evaluated. This study tested the impact of BAC (0.01%) on the stability of Bulinus truncatus eDNA under simulated field conditions. Water samples from aquaria with varying snail densities (0.5–30 snails/L) were stored up to 42 days with BAC. eDNA detection via qPCR and multivariable linear mixed regression analysis revealed that BAC enhanced eDNA stability. eDNA was detectable up to 42 days in samples with ≥1 snail/L and up to 35 days at 0.5 snails/L. Additionally, a positive correlation between snail density and eDNA concentration was observed. These findings support the development of robust eDNA sampling protocols for field surveillance, enabling effective monitoring in remote areas and potentially distinguishing between low- and high-risk schistosomiasis transmission zones.
Journal Article
Wide variation of 'Aedes albopictus' genotypes first introduced into Canary Islands assessed by rDNA internal transcribed spacer region and mtDNA cox1 sequencing and cloning
by
Irene Serafin-Perez
,
Patricio Artigas
,
Carolina Fernandez-Serafin
in
Aedes albopictus
,
Air transportation industry
,
Airports
2025
'Aedes albopictus', one of the most rapidly spreading invasive mosquito species, has expanded from Asia to establish populations on every continent except Antarctica, show- casing exceptional adaptability, particularly in island environments. This study provides the first molecular characterization of 'Ae. albopictus' in the Canary Islands, Spain. Genotyping was conducted using rDNA 5.8S-ITS2 and mtDNA cox1 sequencing, with haplotype analysis and phylogenetic network assessment. Among 49 sequences, 28 distinct 5.8S-ITS2 haplotypes were identified, with individual specimens containing 5 to 17 haplotypes (mean, 10.6). Most haplotypes (26/28; 92.85%) were unique to Tenerife, while only two (7.14%) were shared with other regions. H1 was the most frequent haplotype, shared with Valencia and China, while H2, a short-length haplotype, was shared with Mallorca. For cox1, only two haplotypes were detected: cox1-H1, reported in Europe, China, and Brazil, and a novel haplotype, cox1-H28. This genetic diversity suggests the species' potential capacity to colonize new environments. The findings provide a foundation for further research in the Canary Islands and globally, particularly in regions with high tourism and arbovirus risks, emphasizing the importance of ongoing surveillance and genetic studies to understand the dynamics and public health impacts of invasive mosquito species.
Journal Article
Schistosoma mansoni x S. haematobium hybrids frequently infecting sub-Saharan migrants in southeastern Europe: Egg DNA genotyping assessed by RD-PCR, sequencing and cloning
by
Reguera-Gomez, Marta
,
De Elías-Escribano, Alejandra
,
Salas-Coronas, Joaquín
in
Adult
,
Africa South of the Sahara
,
Africans
2025
Globalization and neglected tropical diseases (NTDs) are increasingly closely linked. In recent years, Spain and Southern Europe are experiencing a considerable increase in the influx of migrants infected by NTDs, mainly from West African countries. This study focuses on imported schistosomiasis and the entry into Europe of hetero-specific hybrids between two human species, Schistosoma mansoni and S. haematobium, causing intestinal and urogenital schistosomiasis respectively.
Individualized genetic identification by molecular analysis using RD-PCR, sequencing and cloning of nuclear rDNA and mtDNA of 134 Schistosoma eggs was performed, including 41 lateral-spined and 84 terminal-spined eggs from urine, and nine lateral-spined eggs from stools. These eggs were recovered from six migrant males from Senegal, Guinea-Bissau, Côte d'Ivoire and Mali, who shared ectopic shedding of S. mansoni-like eggs in their urine. A high hybridization complexity was detected in the eggs of these patients, involving three Schistosoma species. The six patients were infected by S. mansoni x S. haematobium hybrids shedding S. mansoni-like eggs, and also S. haematobium x S. curassoni hybrids shedding S. haematobium-like eggs. SmxSh hybrids were mostly detected in S. mansoni-like eggs from urine (94.59%), whereas in feces the detection of those hybrids was less frequent (5.41%).
This study contributes to: (i) a better understanding of the heterospecific hybrids between S. mansoni and S. haematobium from the genetic point of view; (ii) it shows the frequency with which they are entering non-endemic countries, such as Spain and consequently in Europe; (iii) it determines the diversity of hybrid eggs and haplotypes that can occur within a single patient, e.g., up to two types of hybrids involving three Schistosoma species and up to six different haplotypes; (iv) it provides information to be considered in clinical presentations, diagnosis, responses to treatment and epidemiological impact in relation to possible transmission and establishment in non-endemic areas.
Journal Article
Geographical Influence on Morphometric Variability of Genetically “Pure” Schistosoma haematobium Eggs from Sub-Saharan Migrants in Spain
by
Reguera-Gómez, Marta
,
Bargues, Maria Dolores
,
De Elías-Escribano, Alejandra
in
Bladder
,
CIAS
,
Eggs
2023
Schistosome eggs play a key role in schistosomiasis diagnosis and research. The aim of this work is to morphogenetically study the eggs of Schistosoma haematobium found in sub-Saharan migrants present in Spain, analyzing their morphometric variation in relation to the geographical origin of the parasite (Mali, Mauritania and Senegal). Only eggs considered “pure” S. haematobium by genetic characterization (rDNA ITS-2 and mtDNA cox1) have been used. A total of 162 eggs obtained from 20 migrants from Mali, Mauritania and Senegal were included in the study. Analyses were made by the Computer Image Analysis System (CIAS). Following a previously standardized methodology, seventeen measurements were carried out on each egg. The morphometric analysis of the three morphotypes detected (round, elongated and spindle) and the biometric variations in relation to the country of origin of the parasite on the egg phenotype were carried out by canonical variate analysis. Mahalanobis distances, when all egg measurements were analyzed, showed differences between: (i) Mali-Mauritania, Mali-Senegal and Mauritania-Senegal in the round morphotype; (ii) Mali-Mauritania and Mauritania-Senegal in the elongated morphotype; and (iii) Mauritania-Senegal in the spindle morphotype. Mahalanobis distances, when spine variables were analyzed, showed differences between Mali-Senegal in the round morphotype. In conclusion, this is the first phenotypic study performed on individually genotyped “pure” S. haematobium eggs, allowing the assessment of the intraspecific morphological variations associated with the geographical origin of the schistosome eggs.
Journal Article
Imported Schistosomiasis in Southwestern Europe: Wide Variation of Pure and Hybrid Genotypes Infecting Sub‐Saharan Migrants
by
Salvador, Fernando
,
Sanchez-Marques, Raquel
,
Salas-Coronas, Joaquin
in
Adult
,
Africa South of the Sahara - ethnology
,
Animals
2025
Mitochondrial cox 1 and nuclear ribosomal ITSs are commonly combined to distinguish Schistosoma species and identify hybrids in endemic countries but very rarely applied to patients diagnosed in Europe despite the increasing arrival of migrants in southwestern Europe. To assess whether those migrants are carriers of pure or hybrid schistosomes, a complete genetic characterization of Schistosoma entering Spain is performed. A total of 759 eggs (from urine + stools) from 58 patients from 8 African countries were individually processed to describe their mito‐nuclear signature by cox 1 rapid diagnostic multiplex one‐step polymerase chain reaction (RD‐PCR) and ITS‐2/18S sequencing and haplotype identification by means of the complete ITS1‐5.8S‐ITS2 rDNA and cox 1 sequencing. Combined nuclear and mitochondrial DNA markers in sub‐Saharan migrants residing in Spain are described for the first time. Twenty‐two (40.74%) patients were simultaneously carrying pure and hybrid eggs in their urine. S chistosoma haematobium × S. bovis (68.18%) and S. haematobium × S. curassoni (31.82%) hybrid combinations were the most frequent. Six (one pure and five hybrid) and two (pure) mito‐nuclear signatures, in urine and stools, respectively, and 12 nuclear and 61 mitochondrial imported haplotypes were found. This study highlights the genetic complexity of pure and hybrid schistosomes that enter Spain, and consequently Europe, and contributes to the following: correlate the geographical origin of patients with pure and/or hybrid genetic types; detect the presence of hybrids “at distance” (hybrids in migrants from Guinea‐Bissau and Mauritania are first time detected); correlate molecular haplotypes with pathologies, clinical pictures, and treatment responses; and, importantly, warn about possible sources of autochthonous transmission.
Journal Article
Mating Interactions between Schistosoma bovis and S. mansoni and Compatibility of Their F1 Progeny with Biomphalaria glabrata and Bulinus truncatus
by
Rognon, Anne
,
Onyekwere, Amos Mathias
,
Allienne, Jean-François
in
Animals
,
Biodiversity
,
Biomphalaria glabrata
2022
Contrary to the majority of other Trematoda, Schistosoma species are gonochoric. Consequently, in endemic areas where several schistosome species overlap and can co-infect the same definitive host, there may be frequent opportunities for interspecific pairing. Our experimental study provides novel insight on the pairing behavior between Schistosoma bovis and S. mansoni in mixed infections in mice. We used six mate choice experiments to assess mating interactions between the two schistosome species. We show that mating between the two Schistosoma species is not random and that S. mansoni exhibits greater mate recognition compared to S. bovis. We also performed reciprocal crosses (male S. mansoni × female S. bovis) and (female S. mansoni × male S. bovis) that produce active swimming miracidia. These miracidia were genotyped by ITS2 sequencing and proposed for mollusc infection. Molecular analyses show that all the miracidia are parthenogenetically produced (i.e., their harbor the mother ITS2 genotype) and as a consequence can only infect the mollusc of the maternal species. Offspring produced by male S. mansoni × female S. bovis pairing can only infect Bulinus truncatus whereas offspring produced by female S. mansoni × male S. bovis can only infect Biomphalaria glabrata snails. Evolutionary and epidemiological consequences are discussed.
Journal Article
Wide Variation of Aedes albopictus Genotypes First Introduced into Canary Islands Assessed by rDNA Internal Transcribed Spacer Region and mtDNA cox 1 Sequencing and Cloning
, one of the most rapidly spreading invasive mosquito species, has expanded from Asia to establish populations on every continent except Antarctica, showcasing exceptional adaptability, particularly in island environments. This study provides the first molecular characterization of
in the Canary Islands, Spain. Genotyping was conducted using rDNA 5.8S-ITS2 and mtDNA
1 sequencing, with haplotype analysis and phylogenetic network assessment. Among 49 sequences, 28 distinct 5.8S-ITS2 haplotypes were identified, with individual specimens containing 5 to 17 haplotypes (mean, 10.6). Most haplotypes (26/28; 92.85%) were unique to Tenerife, while only two (7.14%) were shared with other regions. H1 was the most frequent haplotype, shared with Valencia and China, while H2, a short-length haplotype, was shared with Mallorca. For
1, only two haplotypes were detected:
1-H1, reported in Europe, China, and Brazil, and a novel haplotype,
1-H28. This genetic diversity suggests the species' potential capacity to colonize new environments. The findings provide a foundation for further research in the Canary Islands and globally, particularly in regions with high tourism and arbovirus risks, emphasizing the importance of ongoing surveillance and genetic studies to understand the dynamics and public health impacts of invasive mosquito species.
Journal Article
Impact of species hybridization on the clinical management of schistosomiasis: A prospective study
by
Muro, Antonio
,
Cabeza-Barrera, María I.
,
Salas-Coronas, Joaquín
in
Adolescent
,
Adult
,
Africa, Western - epidemiology
2024
Species hybridization represents a real concern in terms of parasite transmission, epidemiology and morbidity of schistosomiasis. It is greatly important to better understand the impact of species hybridization for the clinical management.
A prospective observational study was carried out in sub-Saharan migrants who were diagnosed with confirmed genitourinary schistosomiasis. A tailored protocol was applied, including Schistosoma serology, a specific urine LAMP tests for schistosomiasis and an ultrasound examination before treatment with praziquantel. A scheduled follow-up was performed at 3, 6 and 12 months to monitor treatment response, comparing patients carriers of Schistosoma hybrids with carriers of only genetically pure forms.
A total of 31 male patients from West Africa were included in the study with a mean age of 26.5 years. Twelve (38.7 %) of the patients were carriers of Schistosoma hybrids. As compared with patients infected with S. haematobium alone, hybrid carriers had lower haemoglobin levels (13.8 g/dL [SD 1.8] vs 14.8 g/dL [SD 1.4], p = 0.04), a greater frequency of hematuria (100 % vs 52.6 %, p = 0.005), a higher ultrasound score (2.64, SD 2.20 vs 0.89, SD 0.99; p = 0.02). However, the presence of hybrids did not result in differences in clinical and analytical responses after treatment.
The presence of Schistosoma hybrids seems to cause increased morbidity in infected individuals. However, it does not appear to result in differences in diagnostic tests or in clinical and analytical responses after treatment.
•Hybridization of schistosomes is prevalent in patients with imported schistosomiasis.•Migrants with the presence of hybrid schistosomes present a higher morbidity.•Hybridization does not appear to affect the sensitivity of diagnostic methods.•Hybrid schistosomes does not cause differences in the clinical response to treatment.
Journal Article
Geographical Influence on Morphometric Variability of Genetically “Pure” ISchistosoma haematobium/I Eggs from Sub-Saharan Migrants in Spain
Schistosome eggs play a key role in schistosomiasis diagnosis and research. The aim of this work is to morphogenetically study the eggs of Schistosoma haematobium found in sub-Saharan migrants present in Spain, analyzing their morphometric variation in relation to the geographical origin of the parasite (Mali, Mauritania and Senegal). Only eggs considered \"pure\" S. haematobium by genetic characterization (rDNA ITS-2 and mtDNA cox1) have been used. A total of 162 eggs obtained from 20 migrants from Mali, Mauritania and Senegal were included in the study. Analyses were made by the Computer Image Analysis System (CIAS). Following a previously standardized methodology, seventeen measurements were carried out on each egg. The morphometric analysis of the three morphotypes detected (round, elongated and spindle) and the biometric variations in relation to the country of origin of the parasite on the egg phenotype were carried out by canonical variate analysis. Mahalanobis distances, when all egg measurements were analyzed, showed differences between: (i) Mali-Mauritania, Mali-Senegal and Mauritania-Senegal in the round morphotype; (ii) Mali-Mauritania and Mauritania-Senegal in the elongated morphotype; and (iii) Mauritania-Senegal in the spindle morphotype. Mahalanobis distances, when spine variables were analyzed, showed differences between Mali-Senegal in the round morphotype. In conclusion, this is the first phenotypic study performed on individually genotyped \"pure\" S. haematobium eggs, allowing the assessment of the intraspecific morphological variations associated with the geographical origin of the schistosome eggs.
Journal Article