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Segovia Hernández, Manuel

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Segovia Hernández, Manuel
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Universidad de Murcia. Departamento de Genética y Microbiología
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    Genetic diversity and phylogenetic relationships between Leishmania infantum from dogs, humans and wildlife in south-east Spain
    (Wiley, 2019-08-05) Ortuño, María; Latrofa, María S.; Iborra Bendicho, Maria Asunción; Pérez Cutillas, Pedro; Bernal Gambín, Luis Jesús; Risueño Iranzo, José; Muñoz Hernández, Clara; Bernal, Ana; Sánchez López, Pedro F.; Segovia Hernández, Manuel; Annoscia, Giada; Maia, Carla; Cortes, Sofia; Campino, Lenea; Otranto, Domenico; Berriatua Fernández de Larrea, Eduardo; Sin departamento asociado
    Leishmania infantum causes human and canine leishmaniosis. The parasite, transmitted by phlebotomine sand flies, infects species other than dogs and people, including wildlife, although their role as reservoirs of infection remains unknown for most species. Molecular typing of parasites to investigate genetic variability and evolutionary proximity can help understand transmission cycles and designing control strategies. We investigated Leishmania DNA variability in kinetoplast (kDNA) and internal transcribed spacer 2 (ITS2) sequences in asymptomatically infected wildlife (n = 58) and symptomatically and asymptomatically infected humans (n = 38) and dogs (n = 15) from south-east Spain, using single nucleotide polymorphisms (SNPs) and in silico restriction fragment length polymorphism (RFLP) analyses. All ITS2 sequences (n = 76) displayed a 99%–100% nucleotide identity with a L. infantum reference sequence, except one with a 98% identity to a reference Leishmania panamensis sequence, from an Ecuadorian patient. No heterogeneity was recorded in the 73 L. infantum ITS2 sequences except for one SNP in a human parasite sequence. In contrast, kDNA analysis of 44 L. infantum sequences revealed 11 SNP genotypes (nucleotide variability up to 4.3%) and four RFLP genotypes including B, F and newly described S and T genotypes. Genotype frequency was significantly greater in symptomatic compared to asymptomatic individuals. Both methods similarly grouped parasites as predominantly or exclusively found in humans, in dogs, in wildlife or in all three of them. Accordingly, the phylogenetic analysis of kDNA sequences revealed three main clusters, two as a paraphyletic human parasites clade and a third including dogs, people and wildlife parasites. Results suggest that Leishmania infantum genetics is complex even in small geographical areas and that, probably, several independent transmission cycles take place simultaneously including some connecting animals and humans. Investigating these transmission networks may be useful in understanding the transmission dynamics, infection risk and therefore in planning L. infantum control strategies.
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    Spatial distribution of human asymptomatic Leishmania infantum infection in southeast Spain: a study of environmental, demographic and social risk factors
    (Elsevier, 2015-03-20) Pérez Cutillas, Pedro; Goyena Salgado, Elena; Chitimia Dobler, Lidia; Rúa Tarín, Pilar de la; Bernal Gambín, Luis Jesús; Fisa, Roser; Riera, Cristina Ferri; Iborra Bendicho, Maria Asunción; Murcia, Laura; Segovia Hernández, Manuel; Berriatua Fernández de Larrea, Eduardo; Anatomía y Anatomía Patológica Comparada; Facultades de la UMU::Facultad de Veterinaria
    Recent PCR studies indicate that asymptomatic L. infantum infection is common in people in southern Europe. Understanding its spatial distribution is a requisite to evaluate the public health implications and to design disease control schemes. We investigated infection in blood samples from 657 donors in southeast Spain using PCR and antibody ELISA. They came from 19 blood centers and were interviewed about their residence, occupation, dog ownership and Leishmaniosis awareness. The percentage of PCR and ELISA positives were 8% (49/618) and 2% (13/657). Donor's residences were spatially clustered around blood donning centers and PCR prevalence was 18% in rural municipalities with 20–1330 inhabitants, 12% in those with 1467–5088 inhabitants and 3% in larger communities, and was associated with dog ownership (p < 0.05). Further analysis of data from rural donors indicated that PCR status was strongly related to the climate, altitude and soil type in the donor's residence area and not to other demographic or sociologic variables. Mixed logistic regression analysis predicted PCR prevalence to be greatest in the 200–300 m altitude range with a mean spring–summer (time of highest vector activity) temperature of 18.4–19.0 °C. A temperature and altitude risk map was generated that will provide the basis for elaborating evidence-based vector surveillance studies.
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