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1.
Parasitology ; 146(7): 857-864, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30755288

RESUMEN

Visceral leishmaniasis (VL) was firstly reported in Armenia in 1913. Following a considerable increase of the number of cases until the mid 1950s, the disease disappeared after 1969 and re-emerged in 1999. Scientific literature about VL in Armenia is available only in Russian or Armenian. This paper presents a historical overview about leishmaniasis in Armenia based on this literature as well as an epidemiological update since the re-emergence of the disease. In 1999-2016, 116 indigenous VL cases were recorded mainly in children in 8 of the 11 districts, however, VL is underreported because of lack of trained medical personal and diagnostic facilities. The aim of this work was to apply for the first time molecular diagnosis of VL in Armenia. Out of 25 VL suspected patients, 22 were positive by microscopy and polymerase chain reaction (PCR). Genotyping using internal transcribed spacer 1-PCR-restriction fragment length polymorphism and sequencing identified the causative agent of VL in Armenia as Leishmania infantum. The present work is an important step towards the inclusion of molecular techniques in the current diagnosis of VL in Armenia and the establishment of local molecular diagnostic facilities.


Asunto(s)
Enfermedades Transmisibles Emergentes/diagnóstico , Leishmania infantum/genética , Leishmaniasis Visceral/diagnóstico , Leishmaniasis Visceral/epidemiología , Técnicas de Diagnóstico Molecular , Armenia/epidemiología , Niño , Preescolar , Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/parasitología , ADN Intergénico/genética , Femenino , Genotipo , Humanos , Lactante , Leishmaniasis Visceral/parasitología , Masculino , Persona de Mediana Edad , Tipificación Molecular , Polimorfismo de Longitud del Fragmento de Restricción , Estudios Retrospectivos
2.
Anal Bioanal Chem ; 409(29): 6907-6923, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29080902

RESUMEN

Leishmania species are protozoan parasites and the causative agents of leishmaniasis, a vector borne disease that imposes a large health burden on individuals living mainly in tropical and subtropical regions. Different Leishmania species are responsible for the distinct clinical patterns, such as cutaneous, mucocutaneous, and visceral leishmaniasis, with the latter being potentially fatal if left untreated. For this reason, it is important to perform correct species identification and differentiation. Fourier transform infrared spectroscopy (FTIR) is an analytical spectroscopic technique increasingly being used as a potential tool for identification of microorganisms for diagnostic purposes. By employing mid-infrared (MIR) spectral data, it is not only possible to assess the chemical structures but also to achieve differentiation supported by multivariate statistic analysis. This work comprises a pilot study on differentiation of Leishmania species of the Old World (L. major, L. tropica, L. infantum, and L. donovani) as well as hybrids of distinct species by using vibrational spectroscopic fingerprints. Films of intact Leishmania parasites and their deoxyribonucleic acid (DNA) were characterized comparatively with respect to their biochemical nature and MIR spectral patterns. The strains' hyperspectral datasets were multivariately examined by means of variance-based principal components analysis (PCA) and distance-based hierarchical cluster analysis (HCA). With the implementation of MIR spectral datasets we show that a phenotypic differentiation of Leishmania at species and intra-species level is feasible. Thus, FTIR spectroscopy can be further exploited for building up spectral databases of Leishmania parasites in view of high-throughput analysis of clinical specimens. Graphical abstract For Leishmania species discrimination, sample films of intact parasites and their extracted DNA were analyzed by FTIR micro-spectroscopy. Hyperspectral datasets that comprise mid-infrared fingerprints were submitted to multivariate analysis tools such as principal components analysis (PCA) and hierarchical cluster analysis (HCA).


Asunto(s)
Dermatoglifia del ADN , Leishmania/genética , Espectroscopía Infrarroja por Transformada de Fourier , Análisis por Conglomerados , Humanos , Leishmania/clasificación , Análisis Multivariante , Proyectos Piloto , Análisis de Componente Principal
3.
Exp Parasitol ; 144: 44-51, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24932536

RESUMEN

Most of cutaneous leishmaniasis cases occur in only 7 countries, including Iran. Leishmania tropica is the main cause of anthroponotic cutaneous leishmaniasis in Iran. In order to study the heterogeneity and phylogeny of L. tropica in southern Iran, a total of 61 isolates were obtained from Bam district and the cities Kerman and Shiraz. The internal transcribed spacer (ITS) from the ribosomal DNA locus was amplified and then analysed by sequencing. Analysis of the ITS sequences showed four haplotypes in the isolates, including 3 haplotypes among the 58 isolates from the south eastern region, including Bam district and Kerman city, and 2 haplotypes among the 3 isolates from Shiraz city. The results showed a monophyletic structure for the south eastern population. In comparison to GenBank sequences of L. tropica from different countries, most of the southeast Iranian and Indian isolates are comprised in one cluster, while isolates from other countries and few other Iranian isolates group in a different cluster. Analysis of ITS sequences of south eastern L. tropica showed a homogeneous population which could be the basis for other molecular epidemiology studies using more discriminative markers and tracing possible changes in the population structure of L. tropica.


Asunto(s)
ADN Protozoario/genética , ADN Espaciador Ribosómico/genética , Heterogeneidad Genética , Leishmania tropica/genética , Leishmaniasis Cutánea/parasitología , Adolescente , Adulto , Distribución por Edad , Secuencia de Bases , Niño , Preescolar , ADN Protozoario/química , ADN Espaciador Ribosómico/química , Marcadores Genéticos , Haplotipos , Humanos , Lactante , Irán/epidemiología , Leishmania tropica/clasificación , Leishmaniasis Cutánea/epidemiología , Persona de Mediana Edad , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Adulto Joven
4.
Animal ; 17(3): 100719, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36801550

RESUMEN

Extensive pastoral livestock systems in Central Europe provide multiple ecosystem services and support biodiversity in agricultural landscapes but their viability is challenged by livestock depredation (LD) associated with the recovery of wolf populations. Variation in the spatial distribution of LD depends on a suite of factors, most of which are unavailable at the appropriate scales. To assess if LD patterns can be predicted sufficiently with land use data alone at the scale of one federal state in Germany, we employed a machine-learning-supported resource selection approach. The model used LD monitoring data, and publicly available land use data to describe the landscape configuration at LD and control sites (resolution 4 km * 4 km). We used SHapley Additive exPlanations to assess the importance and effects of landscape configuration and cross-validation to evaluate the model performance. Our model predicted the spatial distribution of LD events with a mean accuracy of 74%. The most influential land use features included grassland, farmland and forest. The risk of livestock depredation was high if these three landscape features co-occurred with a specific proportion. A high share of grassland, combined with a moderate proportion of forest and farmland, increased LD risk. We then used the model to predict the LD risk in five regions; the resulting risk maps showed high congruence with observed LD events. While of correlative nature and lacking specific information on wolf and livestock distribution and husbandry practices, our pragmatic modelling approach can guide spatial prioritisation of damage prevention or mitigation practices to improve livestock-wolf coexistence in agricultural landscapes.


Asunto(s)
Ecosistema , Lobos , Animales , Ganado , Conservación de los Recursos Naturales/métodos , Biodiversidad , Agricultura
5.
Parasitol Res ; 111(4): 1559-68, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22752721

RESUMEN

Resistance to pentavalent antimonials has emerged as a major hurdle to the treatment and control of visceral leishmaniasis (VL), also known as kala-azar (KA), caused by Leishmania donovani. In India, over 60% of KA patients are unresponsive to the first-line drug sodium antimony gluconate (SAG). Resistance determinants in laboratory strains are partly known; however, the mechanism operating in field isolates is not well understood. In this study, we attempted to analyze the genetic polymorphism between SAG sensitive and resistant parasites using a total of 52 L. donovani isolates obtained either from bone marrow of VL patients or from skin lesions of post kala-azar dermal leishmaniasis (PKDL) patients that constitute an important reservoir of parasite. The clinical isolates were analyzed in comparison with L. donovani parasites from reference strains belonging to distinct geographical locations, at internal transcribed spacer 1 region; coding region of gp63 and nine microsatellite repeat regions. Our results demonstrated that both SAG resistant (n = 26) and sensitive (n = 19) Indian isolates, whether causing VL or PKDL, were monomorphic at all the genetic loci tested, unlike the L. donovani in East African or Leishmania infantum in Mediterranean countries where intraspecies variations exist at these loci. Further, the Indian isolates were found closest to the Kenyan isolates of L. donovani on the basis of fragment analysis of microsatellite markers.


Asunto(s)
Antimonio/farmacología , Antiprotozoarios/farmacología , Resistencia a Medicamentos , Leishmania donovani/genética , Leishmaniasis Visceral/parasitología , Polimorfismo Genético , Adolescente , Adulto , Niño , Preescolar , Femenino , Genotipo , Humanos , India , Leishmania donovani/clasificación , Leishmania donovani/efectos de los fármacos , Leishmania donovani/aislamiento & purificación , Masculino , Repeticiones de Microsatélite , Persona de Mediana Edad , Adulto Joven
6.
PLoS Negl Trop Dis ; 15(4): e0009288, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33872307

RESUMEN

BACKGROUND: Visceral leishmaniasis (VL) is re-emerging in Armenia since 1999 with 167 cases recorded until 2019. The objectives of this study were (i) to determine for the first time the genetic diversity and population structure of the causative agent of VL in Armenia; (ii) to compare these genotypes with those from most endemic regions worldwide; (iii) to monitor the diversity of vectors in Armenia; (iv) to predict the distribution of the vectors and VL in time and space by ecological niche modeling. METHODOLOGY/PRINCIPAL FINDINGS: Human samples from different parts of Armenia previously identified by ITS-1-RFLP as L. infantum were studied by Multilocus Microsatellite Typing (MLMT). These data were combined with previously typed L. infantum strains from the main global endemic regions for population structure analysis. Within the 23 Armenian L. infantum strains 22 different genotypes were identified. The combined analysis revealed that all strains belong to the worldwide predominating MON1-population, however most closely related to a subpopulation from Southeastern Europe, Maghreb, Middle East and Central Asia. The three observed Armenian clusters grouped within this subpopulation with strains from Greece/Turkey, and from Central Asia, respectively. Ecological niche modeling based on VL cases and collected proven vectors (P. balcanicus, P. kandelakii) identified Yerevan and districts Lori, Tavush, Syunik, Armavir, Ararat bordering Georgia, Turkey, Iran and Azerbaijan as most suitable for the vectors and with the highest risk for VL transmission. Due to climate change the suitable habitat for VL transmission will expand in future all over Armenia. CONCLUSIONS: Genetic diversity and population structure of the causative agent of VL in Armenia were addressed for the first time. Further genotyping studies should be performed with samples from infected humans, animals and sand flies from all active foci including the neighboring countries to understand transmission cycles, re-emergence, spread, and epidemiology of VL in Armenia and the entire Transcaucasus enabling epidemiological monitoring.


Asunto(s)
Enfermedades Transmisibles Emergentes/diagnóstico , Leishmania infantum/genética , Leishmaniasis Visceral/diagnóstico , Leishmaniasis Visceral/epidemiología , Repeticiones de Microsatélite , Armenia/epidemiología , Preescolar , Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/parasitología , Ecosistema , Femenino , Genotipo , Humanos , Lactante , Leishmaniasis Visceral/parasitología , Masculino , Epidemiología Molecular , Tipificación Molecular , Proyectos Piloto , Polimorfismo de Longitud del Fragmento de Restricción , Medición de Riesgo
7.
Hist Cienc Saude Manguinhos ; 27(4): 1097-1124, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33338179

RESUMEN

This review presents the 100-year history of the Martsinovsky Institute of Medical Parasitology and Tropical Medicine in Moscow, Russia, starting with its foundation and early activities, and also describes the impact of its leading scientists, some of whom became internationally known. The institute headed a network of nine tropical institutes in the various Soviet republics from the 1920s to 1990. The extensive body of literature on the history and research accomplishments of this institute has mainly been published in Russian; our goal here is to introduce these achievements and this expertise to the international scientific and medical community, focusing on malaria and leishmaniasis and the development of measures to control and monitor these diseases in the USSR.


Asunto(s)
Academias e Institutos/historia , Investigación Biomédica/historia , Leishmaniasis/historia , Malaria/historia , Medicina Tropical/historia , Historia del Siglo XX , Humanos , Moscú , Parasitología/educación , Parasitología/historia , U.R.S.S.
8.
Pathogens ; 9(12)2020 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-33317097

RESUMEN

Sand flies (Diptera: Psychodidae: Phlebotominae) are blood-feeding insects that transmit the protozoan parasites Leishmania spp. and various arthropod-borne (arbo) viruses. While in Mediterranean parts of Europe the sand fly fauna is diverse, in Central European countries including Austria mainly Phlebotomus mascittii is found, an assumed but unproven vector of Leishmania infantum. To update the currently understudied sand fly distribution in Austria, a sand fly survey was performed and other entomological catches were screened for sand flies. Seven new trapping locations of Ph. mascittii are reported including the first record in Vienna, representing also one of the first findings of this species in a city. Morphological identification, supported by fluorescence microscopy, was confirmed by two molecular approaches, including sequencing and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) protein profiling. Sand fly occurrence and activity were evaluated based on surveyed locations, habitat requirements and climatic parameters. Moreover, a first comparison of European Ph. mascittii populations was made by two marker genes, cytochrome c oxidase subunit 1 (COI), and cytochrome b (cytb), as well as MALDI-TOF mass spectra. Our study provides new important records of Ph. mascittii in Austria and valuable data for prospective entomological surveys. MALDI-TOF MS protein profiling was shown to be a reliable tool for differentiation between sand fly species. Rising temperatures and globalization demand for regular entomological surveys to monitor changes in species distribution and composition. This is also important with respect to the possible vector competence of Ph. mascittii.

9.
J Clin Microbiol ; 47(9): 2818-25, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19587302

RESUMEN

A multilocus microsatellite typing (MLMT) approach based on the analysis of 15 independent loci has been developed for the discrimination of strains belonging to different Viannia species. Thirteen microsatellite loci were isolated de novo from microsatellite-enriched libraries for both Leishmania braziliensis and L. guyanensis. Two previously identified markers, AC01 and AC16, were modified and added to our marker set. Markers were designed to contain simple dinucleotide repeats flanked by the minimal possible number of nucleotides in order to allow variations in repeat numbers to be scored as size variations of the PCR products. The 15 markers in total were amplified for almost all of the strains of Viannia tested; one marker did not amplify from the two L. peruviana strains included in the study. When 30 strains of L. braziliensis, 21 strains of L. guyanensis, and 2 strains of L. peruviana were tested for polymorphisms, all strains except two strains of L. guyanensis had individual MLMT types. Distance-based analysis identified three main clusters. All strains except one strain of L. guyanensis grouped together. Two clusters consisted of strains of L. braziliensis according to their geographical origins. The two strains of L. peruviana grouped together with strains of L. braziliensis from Peru and the adjacent Brazilian state of Acre. MLMT has proven capable of individualizing strains even from the same areas of endemicity and of detecting genetic structures at different levels. MLMT is thus applicable for epidemiological and population genetic studies of strains within the subgenus Viannia.


Asunto(s)
Dermatoglifia del ADN/métodos , ADN Protozoario/genética , Leishmania/clasificación , Leishmania/genética , Leishmaniasis/parasitología , Repeticiones de Microsatélite , Reacción en Cadena de la Polimerasa/métodos , Animales , Análisis por Conglomerados , ADN Protozoario/química , Genotipo , Geografía , Humanos , Leishmania/aislamiento & purificación , Datos de Secuencia Molecular , Polimorfismo Genético , Análisis de Secuencia de ADN
10.
Infect Genet Evol ; 9(1): 24-31, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18957333

RESUMEN

In this population genetic study of Leishmania donovani parasites in the Indian subcontinent, 132 isolates obtained from patients in Bangladesh, India, Nepal and Sri Lanka suffering from Kala-azar (100), post-Kala-azar dermal leishmaniasis (PKDL) (25) and cutaneous leishmaniasis (CL) (2), and from 5 patients whose clinical patterns were not defined, were analysed by using 15 hyper-variable microsatellite loci. Multilocus microsatellite typing (MLMT) data were analysed by using a Bayesian model-based clustering algorithm and constructing phylogenic tree based on genetic distances. In total, 125 strains from Bangladesh, Bihar (India) and Nepal formed a very homogeneous population regardless of geographical origin, clinical manifestation, and whether they presented in vitro or in vivo susceptibility to antimonial drugs. Identical multilocus microsatellite profiles were found for 108 strains, other strains differed in only one marker. Considerably different microsatellite profiles were identified for three Indian strains most closely related to L. donovani from Kenya, and for four strains from Indian and Sri Lankan CL cases. The circulation of a single homogeneous population of L. donovani in Bihar (India), Bangladesh and Nepal is, most probably, related to the epidemic spread of visceral leishmaniasis in this area.


Asunto(s)
Variación Genética , Leishmania donovani/genética , Leishmaniasis Cutánea/parasitología , Leishmaniasis Visceral/parasitología , Repeticiones de Microsatélite , Animales , Asia Occidental/epidemiología , Técnicas de Tipificación Bacteriana , Teorema de Bayes , Análisis por Conglomerados , Genotipo , Humanos , Leishmania donovani/clasificación , Leishmania donovani/aislamiento & purificación , Leishmaniasis Cutánea/epidemiología , Leishmaniasis Visceral/epidemiología , Cadenas de Markov , Método de Montecarlo , Distribución Normal , Filogenia
11.
Trop Med Int Health ; 14(5): 499-503, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19222820

RESUMEN

Detection of Leishmania parasites in a clinical sample is necessary to confirm a suspected case of leishmaniasis. We compared the sensitivity of internal transcribed spacer 1-PCR (ITS 1-PCR) assay for parasite diagnosis with that of microscopic detection in clinical samples from kala-azar (KA) or post-kala-azar dermal leishmaniasis (PKDL) suspects in Mymensingh. Of 39 specimens collected from 35 KA and four PKDL suspects, 26 were positive by microscopic examination of smears from bone marrow and skin exudates; 38 specimens spotted on filter paper and 27 of the 28 Giemsa-stained slides tested by PCR proved positive by ITS1-PCR.


Asunto(s)
Médula Ósea/parasitología , Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Visceral/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Animales , Bangladesh , ADN Protozoario/análisis , Humanos , Leishmaniasis Cutánea/parasitología , Leishmaniasis Visceral/parasitología , Microscopía , Proteínas Protozoarias/análisis , Proteínas Protozoarias/genética , Sensibilidad y Especificidad
12.
Methods Mol Biol ; 1971: 9-68, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30980297

RESUMEN

Phylogenetics is an important component of the systems biology approach. Knowledge about evolution of the genus Leishmania is essential to understand various aspects of basic biology of these parasites, such as parasite-host or parasite-vector relationships, biogeography, or epidemiology. Here, we present a comprehensive guideline for performing phylogenetic studies based on DNA sequence data, but with principles that can be adapted to protein sequences or other molecular markers. It is presented as a compilation of the most commonly used genetic targets for phylogenetic studies of Leishmania, including their respective primers for amplification and references, as well as details of PCR assays. Guidelines are, then, presented to choose the best targets in relation to the types of samples under study. Finally, and importantly, instructions are given to obtain optimal sequences, alignments, and datasets for the subsequent data analysis and phylogenetic inference. Different bioinformatics methods and software for phylogenetic inference are presented and explained. This chapter aims to provide a compilation of methods and generic guidelines to conduct phylogenetics of Leishmania for nonspecialists.


Asunto(s)
Biología Computacional , ADN Protozoario/genética , Leishmania/genética , Filogenia , Análisis de Secuencia de ADN , Programas Informáticos
13.
Int J Parasitol ; 49(7): 555-567, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31108098

RESUMEN

In the Indian subcontinent, infection with Leishmania donovani can cause fatal visceral leishmaniasis. Genetic variation in L. donovani is believed to occur rapidly from environmental changes and through selective drug pressures, thereby allowing continued disease occurrence in this region. All previous molecular markers that are commonly in use multilocus microsatellite typing and multilocus sequence typing, were monomorphic in L. donovani originating from the Indian subcontinent (with only a few exceptions) and hence are not suitable for this region. An multilocus sequence typing scheme consisting of a new set of seven housekeeping genes was developed in this study, based on recent findings from whole genome sequencing data. This new scheme was used to assess the genetic diversity amongst 22 autochthonous L. donovani isolates from Bangladesh. Nineteen additional isolates of the L. donovani complex (including sequences of L. donovani reference strain BPK282A1) from other countries were included for comparison. By using restriction fragment length polymorphism of the internal transcribed spacer 1 region (ITS1-RFLP) and ITS1 sequencing, all Bangladeshi isolates were confirmed to be L. donovani. Population genetic analyses of 41 isolates using the seven new MLST loci clearly separated L. donovani from Leishmania infantum. With this multilocus sequence typing scheme, seven genotypes were identified amongst Bangladeshi L. donovani isolates, and these isolates were found to be phylogenetically different compared with those from India, Nepal, Iraq and Africa. This novel multilocus sequence typing approach can detect intra- and inter-species variations within the L. donovani complex, but most importantly these molecular markers can be applied to resolve the phylogenetically very homogeneous L. donovani strains from the Indian subcontinent. Four of these markers were found suitable to differentiate strains originating from Bangladesh, with marker A2P being the most discriminative one.


Asunto(s)
Variación Genética , Leishmania donovani/clasificación , Leishmania donovani/genética , Leishmaniasis Visceral/parasitología , Tipificación de Secuencias Multilocus/métodos , Bangladesh , ADN Espaciador Ribosómico/genética , Genotipo , Humanos , Leishmania donovani/aislamiento & purificación , Filogenia , Polimorfismo de Longitud del Fragmento de Restricción , Sensibilidad y Especificidad
14.
BMC Evol Biol ; 8: 183, 2008 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-18577226

RESUMEN

BACKGROUND: Leishmania (Leishmania) major, one of the agents causing cutaneous leishmaniasis (CL) in humans, is widely distributed in the Old World where different species of wild rodent and phlebotomine sand fly serve as animal reservoir hosts and vectors, respectively. Despite this, strains of L. (L.) major isolated from many different sources over many years have proved to be relatively uniform. To investigate the population structure of the species highly polymorphic microsatellite markers were employed for greater discrimination among it's otherwise closely related strains, an approach applied successfully to other species of Leishmania. RESULTS: Multilocus Microsatellite Typing (MLMT) based on 10 different microsatellite markers was applied to 106 strains of L. (L.) major from different regions where it is endemic. On applying a Bayesian model-based approach, three main populations were identified, corresponding to three separate geographical regions: Central Asia (CA); the Middle East (ME); and Africa (AF). This was congruent with phylogenetic reconstructions based on genetic distances. Re-analysis separated each of the populations into two sub-populations. The two African sub-populations did not correlate well with strains' geographical origin. Strains falling into the sub-populations CA and ME did mostly group according to their place of isolation although some anomalies were seen, probably, owing to human migration. CONCLUSION: The model- and distance-based analyses of the microsatellite data exposed three main populations of L. (L.) major, Central Asia, the Middle East and Africa, each of which separated into two sub-populations. This probably correlates with the different species of rodent host.


Asunto(s)
Leishmania major/genética , Repeticiones de Microsatélite/genética , Alelos , Animales , Demografía , Variación Genética , Genética de Población , Geografía , Filogenia
15.
Microbes Infect ; 10(12-13): 1309-15, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18755285

RESUMEN

The present study applies multilocus microsatellite typing (MLMT) for studying the polymorphism among 55 strains of Leishmania infantum from Algeria. These strains from different Algerian foci representing different zymodemes, hosts and clinical forms were analysed using 14 microsatellite markers. All 55 strains had individual MLMT profiles and no relationship was observed between them and different host or geographical origins. Three populations of Algerian L. infantum were identified by a Bayesian clustering approach implemented in STRUCTURE software and supported by genetic distance analysis. Two populations, A and B, consisted mainly of strains belonging to zymodeme MON-1, and the third population, C, mainly of MON-24 strains isolated from cutaneous leishmaniasis cases. Interestingly, a small group of strains appeared as a mixture of different populations and might be putative hybrids. Genetic migration was noticed among the two MON-1 populations, A and B, as well as between populations A and C. Due to its high discriminatory power MLMT could be also successfully applied for differentiating relapses or re-infection for patients suffering from multiple episodes of visceral leishmaniasis.


Asunto(s)
Enfermedades de los Perros/epidemiología , Leishmania infantum/clasificación , Leishmania infantum/genética , Leishmaniasis Cutánea/epidemiología , Leishmaniasis Visceral/epidemiología , Repeticiones de Microsatélite/genética , Polimorfismo Genético , Argelia/epidemiología , Animales , Teorema de Bayes , ADN Protozoario/análisis , ADN Protozoario/aislamiento & purificación , Enfermedades de los Perros/parasitología , Perros , Genética de Población , Genotipo , Humanos , Leishmania infantum/aislamiento & purificación , Leishmaniasis Cutánea/parasitología , Leishmaniasis Visceral/parasitología , Epidemiología Molecular , Análisis de Secuencia de ADN
16.
Microbes Infect ; 9(3): 334-43, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17307010

RESUMEN

Multilocus enzyme electrophoresis (MLEE) is the gold standard for taxonomy and strain typing of Leishmania, but has some limitations. An alternative reliable and fast genotyping method for addressing population genetic and key epidemiological questions, is multilocus microsatellite typing (MLMT). MLMT using 15 markers was applied to 91 strains of L. donovani, L. archibaldi, L. infantum and L. chagasi from major endemic regions of visceral leishmaniasis. Population structures were inferred by combination of Bayesian model-based and distance-based approaches. Six main genetically distinct populations were identified: (1) L. infantum/L. chagasi MON-1 and (2) L. infantum/L. chagasi non-MON-1, both Mediterranean region/South America; (3) L. donovani (MON-18), L. archibaldi (MON-82), L. infantum (MON-30, 81) and (4) L. donovani (MON-31, 274), L. archibaldi (MON-82, 257, 258), L. infantum (MON-267), both Sudan/Ethiopia; (5) L. donovani MON-2, India; (6) L. donovani (MON-36, 37, 38), Kenya and India. Substructures according to place and time of strain isolation were detected. The VL populations seem to be predominantly clonal with a high level of inbreeding. Allelic diversity was highest in the Mediterranean region, intermediate in Africa and lowest in India. MLMT provides a powerful tool for global taxonomic, population genetic and epidemiological studies of the L.donovani complex.


Asunto(s)
Enfermedades Endémicas , Leishmania donovani/clasificación , Leishmaniasis Visceral/epidemiología , Repeticiones de Microsatélite/genética , Proteínas Protozoarias/genética , África Oriental/epidemiología , Animales , ADN Protozoario/análisis , ADN Protozoario/aislamiento & purificación , Genotipo , Humanos , India/epidemiología , Leishmania donovani/genética , Leishmaniasis Visceral/parasitología , Región Mediterránea/epidemiología , Reacción en Cadena de la Polimerasa
17.
Infect Genet Evol ; 7(2): 206-12, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17010679

RESUMEN

Pentavalent antimonials (SbV) are the first line drug against leishmaniasis worldwide, but drug resistance is increasingly reported, particularly in the Indian sub-continent, where it represents a major threat for the control of anthroponotic visceral leishmaniasis (VL). In order to understand the epidemiological dynamics of antimonial resistance in anthroponotic VL, we analysed here the population structure of 24 Leishmania donovani stocks isolated from anthroponotic VL-patients from Eastern Nepal: 13 SbV-naturally resistant and 11 SbV-sensitive, as demonstrated by in vitro drug susceptibility assays. The parasites were genotyped by PCR-RFLP analysis of kDNA minicircles and by microsatellite analysis and the encountered polymorphism revealed a polyclonal structure among resistant isolates. Furthermore, analysis of paired samples obtained from the same patients before treatment and after failure revealed primary as well as acquired resistance. The hypothesis of independent events of drug resistance emergence is proposed and confronted to alternative explanations. Our results show the dynamics of drug resistance epidemiology and highlight the importance of surveillance networks.


Asunto(s)
Antiprotozoarios/uso terapéutico , Leishmania donovani/efectos de los fármacos , Leishmania donovani/genética , Leishmaniasis Visceral/parasitología , Anfotericina B/uso terapéutico , Animales , Médula Ósea/parasitología , ADN de Cinetoplasto/genética , Resistencia a Medicamentos , Genotipo , Humanos , Leishmania donovani/aislamiento & purificación , Leishmaniasis Visceral/tratamiento farmacológico , Nepal , Filogenia , Polimorfismo de Longitud del Fragmento de Restricción
18.
PLoS Negl Trop Dis ; 11(9): e0005873, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28880944

RESUMEN

BACKGROUND: Cutaneous leishmaniasis (CL) is a major public health problem in Libya. In this paper, we describe the eco-epidemiological parameters of CL during the armed conflict period from January 2011 till December 2012. Current spatiotemporal distributions of CL cases were explored and projected to the future using a correlative modelling approach. In addition the present results were compared with our previous data obtained for the time period 1995-2008. METHODOLOGY/PRINCIPAL FINDINGS: We investigated 312 CL patients who presented to the Dermatology Department at the Tripoli Central Hospital and came from 81 endemic areas distributed in 10 districts. The patients presented with typical localized lesions which appeared commonly on the face, arms and legs. Molecular identification of parasites by a PCR-RFLP approach targeting the ITS1 region of the rDNA was successful for 81 patients with two causative species identified: L. major and L. tropica comprised 59 (72.8%) and 22 (27.2%) cases, respectively. Around 77.3% of L. tropica CL and 57.7% of L. major CL caused single lesions. Five CL patients among our data set were seropositive for HIV. L. tropica was found mainly in three districts, Murqub (27.3%), Jabal al Gharbi (27.3%) and Misrata (13.7%) while L. major was found in two districts, in Jabal al Gharbi (61%) and Jafara (20.3%). Seasonal occurrence of CL cases showed that most cases (74.2%) admitted to the hospital between November and March, L. major cases from November till January (69.4%), and L. tropica cases mainly in January and February (41%). Two risk factors were identified for the two species; the presence of previously infected household members, and the presence of rodents and sandflies in patient's neighborhoods. Spatiotemporal projections using correlative distribution models based on current case data and climatic conditions showed that coastal regions have a higher level of risk due to more favourable conditions for the transmitting vectors. CONCLUSION: Future projection of CL until 2060 showed a trend of increasing incidence of CL in the north-western part of Libya, a spread along the coastal region and a possible emergence of new endemics in the north-eastern districts of Libya. These results should be considered for control programs to prevent the emergence of new endemic areas taking also into consideration changes in socio-economical factors such as migration, conflicts, urbanization, land use and access to health care.


Asunto(s)
Leishmania major/genética , Leishmania tropica/genética , Leishmaniasis Cutánea/epidemiología , Leishmaniasis Cutánea/parasitología , Análisis Espacio-Temporal , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Niño , Preescolar , ADN Protozoario/genética , Femenino , Humanos , Lactante , Leishmania major/aislamiento & purificación , Leishmania tropica/aislamiento & purificación , Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Cutánea/transmisión , Libia/epidemiología , Masculino , Persona de Mediana Edad , Psychodidae/parasitología , Roedores/parasitología , Adulto Joven
19.
PLoS Negl Trop Dis ; 11(4): e0005538, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28403153

RESUMEN

Turkey is located in an important geographical location, in terms of the epidemiology of vector-borne diseases, linking Asia and Europe. Cutaneous leishmaniasis (CL) is one of the endemic diseases in a Turkey and according to the Ministry Health of Turkey, 45% of CL patients originate from Sanliurfa province located in southeastern Turkey. Herein, the epidemiological status of CL, caused by L. tropica, in Turkey was examined using multilocus microsatellite typing (MLMT) of strains obtained from Turkish and Syrian patients. A total of 38 cryopreserved strains and 20 Giemsa-stained smears were included in the present study. MLMT was performed using 12 highly specific microsatellite markers. Delta K (ΔK) calculation and Bayesian statistics were used to determine the population structure. Three main populations (POP A, B and C) were identified and further examination revealed the presence of three subpopulations for POP B and C. Combined analysis was performed using the data of previously typed L. tropica strains and Mediterranean and Sanliurfa populations were identified. This finding suggests that the epidemiological status of L. tropica is more complicated than expected when compared to previous studies. A new population, comprised of Syrian L. tropica samples, was reported for the first time in Turkey, and the data presented here will provide new epidemiological information for further studies.


Asunto(s)
Leishmania tropica/aislamiento & purificación , Leishmaniasis Cutánea/epidemiología , Repeticiones de Microsatélite , Colorantes Azulados , Teorema de Bayes , ADN Protozoario/aislamiento & purificación , Variación Genética , Mapeo Geográfico , Humanos , Leishmania tropica/clasificación , Tipificación de Secuencias Multilocus , Filogenia , Siria/epidemiología , Turquía/epidemiología
20.
Mol Aspects Med ; 57: 1-29, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28159546

RESUMEN

Progress in the diagnosis of leishmaniases depends on the development of effective methods and the discovery of suitable biomarkers. We propose firstly an update classification of Leishmania species and their synonymies. We demonstrate a global map highlighting the geography of known endemic Leishmania species pathogenic to humans. We summarize a complete list of techniques currently in use and discuss their advantages and limitations. The available data highlights the benefits of molecular markers in terms of their sensitivity and specificity to quantify variation from the subgeneric level to species complexes, (sub) species within complexes, and individual populations and infection foci. Each DNA-based detection method is supplied with a comprehensive description of markers and primers and proposal for a classification based on the role of each target and primer in the detection, identification and quantification of leishmaniasis infection. We outline a genome-wide map of genes informative for diagnosis that have been used for Leishmania genotyping. Furthermore, we propose a classification method based on the suitability of well-studied molecular markers for typing the 21 known Leishmania species pathogenic to humans. This can be applied to newly discovered species and to hybrid strains originating from inter-species crosses. Developing more effective and sensitive diagnostic methods and biomarkers is vital for enhancing Leishmania infection control programs.


Asunto(s)
Insectos Vectores/parasitología , Leishmania/genética , Leishmaniasis/epidemiología , Tipificación Molecular/métodos , Filogenia , Psychodidae/parasitología , Animales , Antiprotozoarios/farmacología , ADN Protozoario/genética , Genotipo , Humanos , Leishmania/clasificación , Leishmania/efectos de los fármacos , Leishmania/aislamiento & purificación , Leishmaniasis/clasificación , Leishmaniasis/tratamiento farmacológico , Leishmaniasis/transmisión , Tipificación Molecular/instrumentación , Filogeografía , Proteínas Protozoarias/genética , Sensibilidad y Especificidad , Especificidad de la Especie
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