We investigated range-wide phylogeographic variation in three European ash species (Fraxinus sp., Oleaceae). Chloroplast DNA (cpDNA) microsatellites were typed in the thermophilous Fraxinus angustifolia and Fraxinus ornus and the observed haplotypes and the geographic distribution of diversity were compared to cpDNA data previously obtained in the more cold-tolerant Fraxinus excelsior. We found wide-ranging haplotype sharing between the phylogenetically close F. angustifolia and F. excelsior, suggesting hybridization (i) in common glacial refuges in the Iberian Peninsula, northern Italy, the eastern and/or Dinaric Alps and the Balkan Peninsula, and/or (ii) during postglacial recolonization. The data allowed us to propose additional glacial refuges for F. angustifolia in southern Italy and in Turkey, and populations from the latter region were particularly polymorphic. There was evidence for refuge areas in Italy, the Balkan Peninsula and Turkey for F. ornus, which did not share any single chloroplast haplotype with the other species. In both F. angustifolia and F. ornus, cpDNA diversity (h(S) = 0.027 and h(S) = 0.009, respectively) was lower and fixation levels (G(ST) = 0.964 and G(ST) = 0.983, respectively) higher than in sympatric F. excelsior (h(S) = 0.096, G(ST) = 0.870). These diversity patterns could be due to temperature tolerance or the demographic history.
Enzyme-linked immunosorbent assay (ELISA) and micro-ELISA were evaluated for their ability to detect anti-Fasciola hepatica antibodies in humans by using excretory-secretory antigen. The sensitivity of each method was 100%, but the specificity was 100% for ELISA and 97% for micro-ELISA. The micro-ELISA could be used as a screening assay and ELISA could be used as a confirmatory method for the serodiagnosis of human fascioliasis.
BackgroundIn 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.MethodsLymnaeids 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 and Gorczynski continentality index were obtained. Lymnaeid distribution was assessed in environmental studies.ResultsDNA sequences demonstrated the presence of Lymnaea neotropica and L. viator in Locality A and of L. neotropica in Locality B. Two and four new haplotypes were found in L. neotropica and L. viator, respectively. For interspecific differentiation, ITS-1 and 16S showed the highest and lowest resolution, respectively. For intraspecific analyses, cox1 was the best marker and ITS-1 the worst. Shell intraspecific variability overlapped in both species, except maximum length which was greater in L. viator. The desertic-arid conditions surrounding Locality A, the semiaridity-aridity surrounding Locality B, and the very low yearly precipitation in both localities, are very different from the typical fascioliasis transmission foci. Lymnaeids are confined to lateral river side floodings and small man-made irrigation systems. Water availability only depends on the rivers flowing from neighbouring mountains. All disease transmission factors are concentrated in small areas where humans and animals go for water supply, vegetable cultures and livestock farming.ConclusionsThe unusually high number of DNA haplotypes and the extreme climate unsuitable for F. hepatica and lymnaeid development, demonstrate that the transmission foci are isolated. Seasonal transmission may depend on the timely overlap of appropriate temperature and river water availability. Lymnaeids and F. hepatica have probably reached these localities by livestock introduction. DNA differences regarding other populations of L. neotropica and L. viator in Argentina suggest an introduction independent from the spreading movements which allowed these two lymnaeids to expand throughout the country.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1589-z) contains supplementary material, which is available to authorized users.
A new set of 14 chloroplast microsatellites, represented by mono‐ and dinucleotide repeats, was optimized in the three main species of the Fagaceae (Castanea sativa, Fagus sylvatica and Quercus petraea). The intraspecific variation was tested in some natural populations. The polymorphic microsatellites displayed two or three variants. Conservation of the primer pairs was checked on an additional set of six species of the Fagaceae and on Fraxinus excelsior. All the primer pairs produced a fragment of the expected size in the Fagaceae species while no amplification was obtained with 36% of the primers in F. excelsior.
The identification and characterisation of Cryptosporidiumgenotypes
and subtypes are fundamental to the study of cryptosporidiosis epidemiology, aiding
in prevention and control strategies. The objective was to determine the genetic
diversity ofCryptosporidium in samples obtained from hospitals of
Rio de Janeiro, Brazil, and Buenos Aires, Argentina. Samples were analysed by
microscopy and TaqMan polymerase chain reaction (PCR) assays
forCryptosporidium detection, genotyped by nested-PCR-restriction
fragment length polymorphism (RFLP) analysis of the 18S rRNA gene and subtyped by DNA
sequencing of the gp60 gene. Among the 89 samples from Rio de
Janeiro, Cryptosporidium spp were detected in 26 by
microscopy/TaqMan PCR. In samples from Buenos Aires,Cryptosporidium
was diagnosed in 15 patients of the 132 studied. The TaqMan PCR and the
nested-PCR-RFLP detected Cryptosporidium parvum,
Cryptosporidium hominis, and co-infections of both species. In
Brazilian samples, the subtypes IbA10G2 and IIcA5G3 were observed. The subtypes found
in Argentinean samples were IbA10G2, IaA10G1R4, IaA11G1R4, and IeA11G3T3, and mixed
subtypes of Ia and IIa families were detected in the co-infections. C.
hominis was the species more frequently detected, and subtype family Ib
was reported in both countries. Subtype diversity was higher in Buenos Aires than in
Rio de Janeiro and two new subtypes were described for the first time.
The distribution of haplotypic diversity of 17 Tilia cordata Mill. populations was investigated by PCRRFLP markers of the chloroplast genomes. A high number of haplotypes (14) and high total genetic diversity (hT = 0.881) were detected. The distribution of the chloroplast DNA haplotypes revealed low geographic structure of the genetic diversity; the coefficient of differentiation between populations, Gst = 0.552, was lower than the mean value reported for maternally inherited markers in Angiosperm tree species. The value of population subdivision for ordered alleles, as measured by Nst, was significantly higher than the value of population subdivision for unordered alleles (Nst = 0.662, Gst = 0.552), thus indicating the presence of a phylogeographic structure. The relatively low genetic differentiation among T. cordata populations may be explained mainly as a consequence of human impact on this species.
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