0000000000006743
AUTHOR
María Dolores Bargues
Human fascioliasis endemic areas in Argentina: multigene characterisation of the lymnaeid vectors and climatic-environmental assessment of the transmission pattern
Background: In South America, fascioliasis stands out due to the human endemic areas in many countries. In Argentina, human endemic areas have recently been detected. Lymnaeid vectors were studied in two human endemic localities of Catamarca province: Locality A beside Taton and Rio Grande villages; Locality B close to Recreo town. Methods: Lymnaeids were characterised by the complete sequences of rDNA ITS-2 and ITS-1 and fragments of the mtDNA 16S and cox1. Shell morphometry was studied with the aid of a computer image analysis system. Climate analyses were made by nearest neighbour interpolation from FAO data. Koeppen & Budyko climate classifications were used. De Martonne aridity index a…
Triatomine vectors of Trypanosoma cruzi: a molecular perspective based on nuclear ribosomal DNA markers.
Chagas disease (American trypanosomiasis) is mainly transmitted by blood-sucking bugs of the reduviid subfamily Triatominae (Hemiptera: Prosorrhyncha). Control strategies are directed mainly against these insect vectors, as no vaccine is available and, except in the very early stage of infection, there is no effective chemotherapy. Studies of deoxyribonucleic acid (DNA) will lead to major advances in our knowledge of Triatominae and their relationships to Chagas disease transmission, epidemiology and control. Analyses of complete sequences of nuclear genes coding for ribosomal ribonucleic acid (rRNA) (rRNA genes) and spacers furnish significant information at the levels of higher taxons, ge…
Genetic and phenotypic variation of the malaria vector Anopheles atroparvus in southern Europe
Abstract Background There is a growing concern that global climate change will affect the potential for pathogen transmission by insect species that are vectors of human diseases. One of these species is the former European malaria vector, Anopheles atroparvus. Levels of population differentiation of An. atroparvus from southern Europe were characterized as a first attempt to elucidate patterns of population structure of this former malaria vector. Results are discussed in light of a hypothetical situation of re-establishment of malaria transmission. Methods Genetic and phenotypic variation was analysed in nine mosquito samples collected from five European countries, using eight microsatell…
American Trypanosomiasis Chagas disease : one hundred years of research
Abstract In understanding biodiversity, taxonomy and systematics work together, although the two terms are often confused. The objective of systematics is to understand the natural mechanisms responsible for the biodiversity, while the task of taxonomy is to set up a useful classification of the organisms concerned. The Triatominae (Hemiptera, Reduviidae) are the vectors of Chagas disease. Their classification faces frequent divergence between the modern concepts of systematics and the traditional, morphologically-based, classification. This chapter revises the main concepts of species in general, and their application to the Triatominae. We summarize the current classification of the vecto…
SSU rDNA Characterization of Lymnaeid Snails Transmitting Human Fascioliasis in South and Central America
The small subunit (18S) rRNA gene sequences of the lymnaeid morphs I and II (Mollusca: Gastropoda: Basommatophora: Lymnaeidae) transmitting human fascioliasis in the high endemic zone of the northern Bolivian Altiplano and of Lymnaea cubensis from Mexico and Guadeloupe island (Caribbean) have been obtained by direct polymerase chain reaction PCR cycle sequencing and silver staining methods and compared to that of the 6 most common European Lymnaeidae species. Results allow us to establish definitively the distinction between the lymnaeids from the northern Bolivian Altiplano and L. cubensis. Lymnaea cubensis is a valid species distributed in North and Central America but absent in the north…
Intraspecific variation within Phlebotomus sergenti Parrot (1917) (Diptera: Psychodidae) based on mtDNA sequences in Islamic Republic of Iran.
An intraspecific study on the morphological and molecular characteristics of Phlebotomus sergenti s.l., the main vector of Leishmania tropica, was performed on 28 Iranian populations from 11 provinces and a few samples from Greece, Morocco, Lebanon, Turkey, Pakistan, and Syria. Three morphotypes were identified as A, B and C, with some intermediate forms in the samples under investigation. Based on the number of setae and the width of basal lobe of coxite, differences between A and B morphotypes were highly significant. Excluding one unusual haplotype, sequence analysis of ∼439 bp of mtDNA (a fragment of cytochromeB gene, tRNA for serine gene, and a fragment of NADH1 gene) revealed a 6–7% g…
Evidence of autochthonous transmission of urinary schistosomiasis in Almeria (southeast Spain): An outbreak analysis.
Abstract Background Schistosomiasis is endemic in 78 countries belonging to tropical and subtropical areas. However, autochthonous transmission of urogenital schistosomiasis was reported in Corsica (France) in 2013. We present evidence of autochthonous transmission of urogenital schistosomiasis in Almeria (Spain) in 2003. Methods Description of the outbreak in farmers and subsequent epidemiological studies aimed at searching for Bulinus snails and their genotypic characteristics. Results The outbreak affected 4 farmers out of a group of 5 people who repeatedly bathed that summer in an irrigation pool in the area. Two of them presented macroscopic hematuria with bilharziomas, showing the pre…
Lymnaea schirazensis, an Overlooked Snail Distorting Fascioliasis Data: Genotype, Phenotype, Ecology, Worldwide Spread, Susceptibility, Applicability
BackgroundLymnaeid snails transmit medical and veterinary important trematodiases, mainly fascioliasis. Vector specificity of fasciolid parasites defines disease distribution and characteristics. Different lymnaeid species appear linked to different transmission and epidemiological patterns. Pronounced susceptibility differences to absolute resistance have been described among lymnaeid populations. When assessing disease characteristics in different endemic areas, unexpected results were obtained in studies on lymnaeid susceptibility to Fasciola. We undertook studies to understand this disease transmission heterogeneity.Methodology/principal findingsA ten-year study in Iran, Egypt, Spain, t…
Chapter 2 Fasciola, Lymnaeids and Human Fascioliasis, with a Global Overview on Disease Transmission, Epidemiology, Evolutionary Genetics, Molecular Epidemiology and Control
Abstract Fascioliasis, caused by liver fluke species of the genus Fasciola, has always been well recognized because of its high veterinary impact but it has been among the most neglected diseases for decades with regard to human infection. However, the increasing importance of human fascioliasis worldwide has re‐launched interest in fascioliasis. From the 1990s, many new concepts have been developed regarding human fascioliasis and these have furnished a new baseline for the human disease that is very different to a simple extrapolation from fascioliasis in livestock. Studies have shown that human fascioliasis presents marked heterogeneity, including different epidemiological situations and…
A nuclear ribosomal DNA pseudogene in triatomines opens a new research field of fundamental and applied implications in Chagas disease
A pseudogene, designated as "ps(5.8S+ITS-2)", paralogous to the 5.8S gene and internal transcribed spacer (ITS)-2 of the nuclear ribosomal DNA (rDNA), has been recently found in many triatomine species distributed throughout North America, Central America and northern South America. Among characteristics used as criteria for pseudogene verification, secondary structures and free energy are highlighted, showing a lower fit between minimum free energy, partition function and centroid structures, although in given cases the fit only appeared to be slightly lower. The unique characteristics of "ps(5.8S+ITS-2)" as a processed or retrotransposed pseudogenic unit of the ghost type are reviewed, wi…
The ITS-2 of the nuclear rDNA as a molecular marker for populations, species, and phylogenetic relationships in Triatominae (Hemiptera: Reduviidae), vectors of Chagas disease.
The nucleotide sequences of the rDNA second internal transcribed spacer (ITS-2) of 31 populations of 12 and 3 species of the two main Triatominae tribes Triatomini and Rhodniini, including the most important Chagas disease vectors, were obtained. Sequence comparisons and parsimony, distance, and maximum-likelihood analyses indicate that ITS-2 is a useful marker for resolving supraspecific, specific, subspecific, and even sometimes population-level relationships in Triatominae. Results were markedly different between species of Triatomini and Rhodniini, suggesting polyphyly. Phylogenetic trees support an old divergence between South American and North-Central American Triatomini and query th…
Fascioliasis transmission by Lymnaea neotropica confirmed by nuclear rDNA and mtDNA sequencing in Argentina
Fascioliasis is widespread in livestock in Argentina. Among activities included in a long-term initiative to ascertain which are the fascioliasis areas of most concern, studies were performed in a recreational farm, including liver fluke infection in different domestic animal species, classification of the lymnaeid vector and verification of natural transmission of fascioliasis by identification of the intramolluscan trematode larval stages found in naturally infected snails. The high prevalences in the domestic animals appeared related to only one lymnaeid species present. Lymnaeid and trematode classification was verified by means of nuclear ribosomal DNA and mitochondrial DNA marker sequ…
Aplicação do conceito One Health na área hiperendêmica de fasciolíase humana do Altiplano Boliviano: biologia dos limneídeos, dinâmica populacional, microecologia e influência de fatores climáticos
Abstract Fascioliasis is a freshwater snail-borne zoonotic disease. The Northern Bolivian Altiplano is a very high altitude endemic area where the highest human prevalences and intensities have been reported. Preventive chemotherapy by treatment campaigns is yearly applied. However, liver fluke infection of cattle, sheep, pigs and donkeys assures endemicity and consequent human infection and re-infection risks. A One Health action has therefore been implemented. Activity concerns lymnaeid vectors and environment diversity. Studies included growth, egg-laying and life span in laboratory-reared lymnaeids. Different habitat types and influencing factors were assessed. All populations proved to…
DNA multigene characterization of Fasciola hepatica and Lymnaea neotropica and its fascioliasis transmission capacity in Uruguay, with historical correlation, human report review and infection risk analysis.
Background Fascioliasis is a pathogenic disease transmitted by lymnaeid snails and recently emerging in humans, in part due to effects of climate changes, anthropogenic environment modifications, import/export and movements of livestock. South America is the continent presenting more human fascioliasis hyperendemic areas and the highest prevalences and intensities known. These scenarios appear mainly linked to altitude areas in Andean countries, whereas lowland areas of non-Andean countries, such as Uruguay, only show sporadic human cases or outbreaks. A study including DNA marker sequencing of fasciolids and lymnaeids, an experimental study of the life cycle in Uruguay, and a review of hum…
First description of the male of Phlebotomus betisi Lewis and Wharton, 1963 (Diptera: Psychodidae).
The male of Phlebotomus (Larroussius) betisi is described from Malayan caves. Several males have been caught in association with P. betisi females. Males and females have been associated by ecology, biogeography, morphology and molecular biology (homology of the ND4 mtDNA sequences).
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
Simple Summary Fasciolid flukes collected from sheep and cattle in Ecuador showed a high diversity in DNA sequences whose analyses indicated introductions from South America, European and North American countries. These results agree with the numerous livestock importations performed by Ecuador. Abnormally big-sized liver flukes were found in Ecuadorian sheep. The morphometric phenotypic CIAS study showed that its size maximum and mean very pronouncedly and significantly surpassed those of the Fasciola hepatica populations from South America and Spain and proved to be intermediate between standard F. hepatica and F. gigantica populations. Such a feature is only known in intermediate fasciol…
Malaria resurgence risk in southern Europe: climate assessment in an historically endemic area of rice fields at the Mediterranean shore of Spain
Abstract Background International travel and immigration have been related with an increase of imported malaria cases. This fact and climate change, prolonging the period favouring vector development, require an analysis of the malaria transmission resurgence risk in areas of southern Europe. Such a study is made for the first time in Spain. The Ebro Delta historically endemic area was selected due to its rice field landscape, the presence of only one vector, Anopheles atroparvus, with densities similar to those it presented when malaria was present, in a situation which pronouncedly differs from already assessed potential resurgence areas in other Mediterranean countries, such as France an…
Classification and Phylogeny of the Triatominae
Publisher Summary Perhaps the greatest challenge for the classification of Triatominae is the lack of a unifying concept of species. To discuss some of the conflicts that arise from applying modern concepts to traditional classification, and to highlight some recurrent practices regarding the systematics of the subfamily, this chapter develops this discussion in parallel with the traditional and modern concepts of species. In understanding biodiversity, one must understand that taxonomy and systematics work together, although the two terms are often confused. Divergence between the modern concepts of systematics starts at the definition given to the taxa they wish to analyze: single individ…
Hyperendemic fascioliasis associated with schistosomiasis in villages in the Nile Delta of Egypt.
Coprologic surveys were carried out in villages of the Behera Governorate in the Nile Delta region of Egypt to characterize the epidemiologic features of human fascioliasis caused by Fasciola hepatica and F. gigantica in this lowland endemic area by comparison with fascioliasis caused by only F. hepatica in areas hyperendemic for human disease in the Andean highlands of South America. The fascioliasis prevalences detected (range = 5.2-19.0%, mean = 12.8%) are the highest obtained in Egypt. The comparison with previous results suggests that in the Nile Delta, fascioliasis is spreading from an original situation of sporadic human cases in well-known endemic foci for animal disease to an endem…
West Nile virus in Spain: Forecasting the geographical distribution of risky areas with an ecological niche modelling approach.
West Nile virus (WNV), a well-known emerging vector-borne arbovirus with a zoonotic life cycle, represents a threat to both public and animal health. Transmitted by ornithophilic mosquitoes, its transmission is difficult to predict and even more difficult to prevent. The massive and unprecedented number of human cases and equid outbreaks in Spain during 2020 interpellates for new approaches. For the first time, we present an integrate analysis from a niche perspective to provide an insight to the situation of West Nile disease (WND) in Spain. Our modelling approach benefits from the combined use of global occurrence records of outbreaks of WND in equids and of its two alleged main vectors i…
Plant-Borne Trematode Zoonoses: Fascioliasis and Fasciolopsiasis
There are six plant-borne trematode species known affecting humans: Fasciola hepatica, F. gigantica, and Fasciolopsis buski (Fasciolidae), Gastrodiscoides hominis (Gastrodiscidae), Watsonius watsoni, and Fischoederius elongatus (Paramphistomidae). Whereas F. hepatica and F. gigantica are hepatic, the other four species are intestinal parasites.
Aedes albopictus diversity and relationships in south-western Europe and Brazil by rDNA/mtDNA and phenotypic analyses: ITS-2, a useful marker for spread studies
AbstractBackgroundAedes albopictusis a very invasive mosquito, which has recently colonized tropical and temperate regions worldwide. Of concern is its role in the spread of emerging or re-emerging mosquito-borne diseases.Ae. albopictusfrom south-western Europe and Brazil were studied to infer genetic and phenetic diversity at intra-individual, intra-population and inter-population levels, and to analyse its spread.MethodsGenotyping was made by rDNA 5.8S-ITS-2 and mtDNAcox1 sequencing to assess haplotype and nucleotide diversity, genetic distances and phylogenetic networks. Male and female phenotyping included combined landmark-and outlined-based geometric morphometrics of wing size and sha…
Intermediate hosts of Angiostrongylus cantonensis in Tenerife, Spain.
The nematode Angiostrongylus cantonensis is the causative agent of human angiostrongy- liasis, the main clinical manifestation of which is eosinophilic meningitis. Although this para- site has been found recently in its definitive rat host in Tenerife (Canary Islands, Spain), showing a widespread distribution over the north-east part of the island, there are no avail- able data regarding which snail and/or slug species are acting as intermediate hosts on this island. Consequently, the objective of this work was to determine the possible role of three mollusc species, Plutonia lamarckii , Cornu aspersum and Theba pisana , as intermediate hosts of A . cantonensis in Tenerife. Between 2011 and…
Fascioliasis in Llama, Lama glama, in Andean Endemic Areas: Experimental Transmission Capacity by the High Altitude Snail Vector Galba truncatula and Epidemiological Analysis of Its Reservoir Role
Simple Summary The infection by the liver fluke Fasciola hepatica in South American camelids, mainly llamas and alpacas, has been the focus of many studies. However, their capacity to participate in the transmission of the disease and their potential reservoir role in human or animal endemic areas have never been studied. Therefore, all development stages of an isolate from Argentine llama of the high Andean plateau have been experimentally investigated, from egg embryogenesis to metacercarial infectivity, by using the vector snail Galba truncatula from the high altitude Bolivian Altiplano human hyperendemic area. Although eggs shed by llamas may successfully develop until the adult stage i…
Climate change effects on trematodiases, with emphasis on zoonotic fascioliasis and schistosomiasis.
The capacity of climatic conditions to modulate the extent and intensity of parasitism is well known since long ago. Concerning helminths, among the numerous environmental modifications giving rise to changes in infections, climate variables appear as those showing a greater influence, so that climate change may be expected to have an important impact on the diseases they cause. However, the confirmation of the impact of climate change on helminthiases has been reached very recently. Only shortly before, helminthiases were still noted as infectious diseases scarcely affected by climate change, when compared to diseases caused by microorganisms in general (viruses, bacteriae, protozoans). Th…
Genetic variability and geographical diversity of the main Chagas' disease vector Panstrongylus megistus (Hemiptera: Triatominae) in Brazil based on ribosomal DNA intergenic sequences.
Studies were made on the ribosomal DNA intergenic region, comprising complete internal transcribed spacer (ITS)-1, 5.8S, and ITS-2 sequences, of populations of the triatomine Panstrongylus megistus, the most important vector of Chagas' disease in Brazil since Triatoma infestans eradication. Specimens were from 26 localities of Rio Grande do Sul, Santa Catarina, Paraná, São Paulo, Minas Gerais, Bahia, and Sergipe states. In total, 21 ITS-1 and 12 ITS-2 haplotypes were found. Nucleotide differences were higher in ITS-1 (3.00%) than in ITS-2 (1.33%). The intergenic region was 1,513-1,522-bp-long (mean 1,516.9 bp), providing 26 combined haplotypes. The combination of microsatellites found in bo…
Finding of Parastrongylus cantonensis (Chen, 1935) in Rattus rattus in Tenerife, Canary Islands (Spain).
Parastrongylus cantonensis is a parasite of murid rodents that can infect humans and cause health problems as eosinophilic meningitis. Although it is endemic in south Asia, the Pacific islands, Australia, USA, and a few Caribbean islands, it has been extended to new geographical regions. In the Canary Islands (Spain) a survey of helminths of Rattus rattus, Rattus norvegicus and Mus musculus domesticus was carried out. Furthermore, five species of molluscs were examined for nematode larvae to determine whether they are potential intermediate hosts of P. cantonensis. Nematodes were found in the lungs of 15% of 67 R. rattus examined in Tenerife, one of the four studied islands, with a prevalen…
Genetic structure of Triatoma venosa (Hemiptera: Reduviidae): molecular and morphometric evidence.
Triatoma venosa presents a restricted geographical distribution in America and is considered as a secondary vector of Chagas disease in Colombia and Ecuador. A total of 120 adult insects were collected in domestic and peridomestic habitats in an endemic area of the department of Boyaca, Colombia, in order to determine their genetic structure through morphometric and molecular techniques. The head and wings of each specimen were used for the analyses of size, shape, and sexual dimorphism. A significant sexual dimorphism was found, although no differences in size among the studied groups were detected. Differences were found in the analyzed structures except for male heads. DNA was extracted …
Genetically 'pure' Fasciola gigantica discovered in Algeria: DNA multimarker characterization, trans-Saharan introduction from a Sahel origin and spreading risk into north-western Maghreb countries.
Fascioliasis is a freshwater snail-borne zoonotic helminth disease caused by two species of trematodes: Fasciola hepatica of almost worldwide distribution and the more pathogenic F. gigantica restricted to parts of Asia and most of Africa. Of high pathological impact in ruminants, it underlies large livestock husbandry losses. Fascioliasis is moreover of high public health importance and accordingly included within the main neglected tropical diseases by WHO. Additionally, this is an emerging disease due to influences of climate and global changes. In Africa, F. gigantica is distributed throughout almost the whole continent except in the north-western Maghreb countries of Morocco, Algeria a…
DNA multigene sequencing of topotypic specimens of the fascioliasis vector Lymnaea diaphana and phylogenetic analysis of the genus Pectinidens (Gastropoda)
Freshwater lymnaeid snails are crucial in defining transmission and epidemiology of fascioliasis. In South America, human endemic areas are related to high altitudes in Andean regions. The species Lymnaea diaphana has, however, been involved in low altitude areas of Chile, Argentina and Peru where human infection also occurs. Complete nuclear ribosomal DNA 18S, internal transcribed spacer (ITS)-2 and ITS-1 and fragments of mitochondrial DNA 16S and cytochrome c oxidase (cox)1 genes of L. diaphana specimens from its type locality offered 1,848, 495, 520, 424 and 672 bp long sequences. Comparisons with New and Old World Galba/Fossaria, Palaearctic stagnicolines, Nearctic stagnicolines, Old Wo…
Phylogeography and genetic variation of Triatoma dimidiata, the main Chagas disease vector in Central America, and its position within the genus Triatoma.
Background Among Chagas disease triatomine vectors, the largest genus, Triatoma, includes species of high public health interest. Triatoma dimidiata, the main vector throughout Central America and up to Ecuador, presents extensive phenotypic, genotypic, and behavioral diversity in sylvatic, peridomestic and domestic habitats, and non-domiciliated populations acting as reinfestation sources. DNA sequence analyses, phylogenetic reconstruction methods, and genetic variation approaches are combined to investigate the haplotype profiling, genetic polymorphism, phylogeography, and evolutionary trends of T. dimidiata and its closest relatives within Triatoma. This is the largest interpopulational …
Combined phylogenetic and morphometric information to delimit and unify the Triatoma brasiliensis species complex and the Brasiliensis subcomplex
Made available in DSpace on 2018-12-11T16:46:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-06-01 “Triatoma brasiliensis species complex” was defined as a monophyletic group of the species: T. brasiliensis, T. juazeirensis, T. melanica, and T. sherlocki. An alternative grouping scheme proposed the concept of “Brasiliensis subcomplex” which included the former species together with T. melanocephala, T. petrocchiae, T. lenti, T. tibiamaculata, and T. vitticeps. To evaluate the relationship among these taxa we combined the results obtained with four mitochondrial genes (12S, 16S, COI and Cytb, adding to 1811 bp) and geometric morphometric analysis of wings and heads. Panstrongylus m…
Angiogenic response in an in vitro model of dog microvascular endothelial cells stimulated with antigenic extracts from Dirofilaria immitis adult worms
Abstract Background Angiogenesis can occur under pathological conditions when stimuli such as inflammation, vascular obstruction or hypoxia exist. These stimuli are present in cardiopulmonary dirofilariosis (Dirofilaria immitis). The aim of this study was to analyze the capacity of D. immitis antigens to modify the expression of angiogenic factors and trigger the formation of pseudocapillaries (tube-like structures) in an in vitro model of endothelial cells. Methods The expression of VEGF-A, sFlt, mEndoglin and sEndoglin in cultures of canine microvascular endothelial cells stimulated with extract of adult worms of D. immitis obtained from an untreated dog (DiSA) and from a dog treated for …
Genomic Changes of Chagas Disease Vector, South America
We analyzed the main karyologic changes that have occurred during the dispersion of Triatoma infestans, the main vector of Chagas disease. We identified two allopatric groups, named Andean and non-Andean. The Andean specimens present C-heterochromatic blocks in most of their 22 chromosomes, whereas non-Andean specimens have only 4-7 autosomes with C-banding. These heterochromatin differences are the likely cause of a striking DNA content variation (approximately 30%) between Andean and non-Andean insects. Our study, together with previous historical and genetic data, suggests that T. infestans was originally a sylvatic species, with large quantities of DNA and heterochromatin, inhabiting th…