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1.
PLoS Negl Trop Dis ; 14(12): e0008967, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33370303

RESUMEN

Phlebotomine sand flies employ an elaborate system of pheromone communication wherein males produce pheromones that attract other males to leks (thus acting as an aggregation pheromone) and females to the lekking males (sex pheromone). In addition, the type of pheromone produced varies among populations. Despite the numerous studies on sand fly chemical communication, little is known of their chemosensory genome. Chemoreceptors interact with chemicals in an organism's environment to elicit essential behaviors such as the identification of suitable mates and food sources. Thus, they play important roles during adaptation and speciation. Major chemoreceptor gene families, odorant receptors (ORs), gustatory receptors (GRs) and ionotropic receptors (IRs) together detect and discriminate the chemical landscape. Here, we annotated the chemoreceptor repertoire in the genomes of Lutzomyia longipalpis and Phlebotomus papatasi, major phlebotomine vectors in the New World and Old World, respectively. Comparison with other sequenced Diptera revealed a large and unique expansion where over 80% of the ~140 ORs belong to a single, taxonomically restricted clade. We next conducted a comprehensive analysis of the chemoreceptors in 63 L. longipalpis individuals from four different locations in Brazil representing allopatric and sympatric populations and three sex-aggregation pheromone types (chemotypes). Population structure based on single nucleotide polymorphisms (SNPs) and gene copy number in the chemoreceptors corresponded with their putative chemotypes, and corroborate previous studies that identified multiple populations. Our work provides genomic insights into the underlying behavioral evolution of sexual communication in the L. longipalpis species complex in Brazil, and highlights the importance of accounting for the ongoing speciation in central and South American Lutzomyia that could have important implications for vectorial capacity.


Asunto(s)
Células Quimiorreceptoras/metabolismo , Proteínas de Insectos/genética , Leishmaniasis/prevención & control , Leishmaniasis/transmisión , Phlebotomus/parasitología , Atractivos Sexuales/química , Animales , Brasil , Femenino , Insectos Vectores/parasitología , Leishmania , Masculino , Phlebotomus/genética , Phlebotomus/fisiología , Polimorfismo de Nucleótido Simple/genética
2.
Mol Immunol ; 127: 95-106, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32949849

RESUMEN

Leishmania infantum infection may cause visceral leishmaniasis (VL), a fatal disease having worldwide distribution, that may be silent or asymptomatic. The latter indicates that immunity is naturally developed in some individuals, and, therefore, a vaccine against VL would be possible. Molecular mechanisms of gene expression are being understood in Leishmania, and this knowledge may be useful for vaccine development. The aim of this study was developing an attenuated strain by regulating the expression of toxic proteins in a stage specific manner. For that purpose, the 3' UTR of an amastin gene, known by its increased expression in the amastigote phase, was selected for direct the expression of exogenous proteins. This construct (pFL-AMA), firstly, was proved effective for the expression of mCherry specifically in the intracellular form of L. infantum, as demonstrated by fluorescence microscopy, flow cytometry and Western blotting. Afterwards, mCherry coding sequence was replaced, in the pFL-AMA plasmid, by either egg avidin or the active form of bovine trypsin. Viability of transfected parasites was evaluated in promastigote axenic cultures and in in vitro infection of macrophages. Both lines of transfected parasites showed a limited capacity to multiply inside macrophages. BALB/c mice were inoculated intraperitoneally (i.p.) with a single dose consisting of 2 × 106L. infantum promastigotes transfected with plasmids bearing the toxic genes. After 10 weeks post-inoculation, no parasites were recovered by limiting dilution in either liver or spleen, but a specific immunological response was detected. The immunization with transfected parasites induced cellular and humoral immune responses with activation of TCD4+, TCD8+ and B cells, having a TH1-type response with increased levels of pro-inflammatory cytokines such as IFN-γ, TNF-α and IL-6. In parallel groups of mice, a challenge consisting on 1 × 106 virulent parasites of either L. infantum (inoculated i.p.) or L. amazonensis subcutaneously (s.c.) was performed. Vaccinated mice, challenged with L. infantum, showed lower parasite burdens in liver, spleen and bone marrow than infected mice with WT L. infantum (non-vaccinated); similarly, vaccinated mice developed smaller footpad inflammation than control group. These data support this strategy as an efficient immunization system aimed to the development of vaccines against different forms of leishmaniasis.


Asunto(s)
Leishmania infantum/fisiología , Leishmania/fisiología , Leishmaniasis/prevención & control , Leishmaniasis/parasitología , Plásmidos/metabolismo , Toxinas Biológicas/metabolismo , Transfección , Animales , Femenino , Regulación de la Expresión Génica , Humanos , Inmunidad Celular , Inmunidad Humoral , Inmunización , Leishmania/patogenicidad , Leishmania infantum/crecimiento & desarrollo , Leishmania infantum/patogenicidad , Leishmaniasis/inmunología , Estadios del Ciclo de Vida , Ratones Endogámicos BALB C , Parásitos/metabolismo , Parásitos/patogenicidad , Proteínas Protozoarias/metabolismo , Virulencia
3.
PLoS One ; 15(6): e0234445, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32579586

RESUMEN

This study aimed to describe the sand fly fauna and detect trypanosomatids in these insects from Casa Branca, state of Minas Gerais, Brazil, an endemic area of both visceral (VL) and tegumentary leishmaniasis (TL). Sand flies were collected bimonthly from May 2013 to July 2014, using automatic light traps exposed for three consecutive nights in peridomiciliary areas of nine houses with previous reports of VL and TL. ITS1-PCR and DNA sequencing were performed for trypanosomatids identification. A total of 16,771 sand flies were collected belonging to 23 species. The most abundant species was Nyssomyia whitmani (Antunes & Coutinho, 1939) (70.9%), followed by Lutzomyia longipalpis (Lutz & Neiva, 1912) (15.2%) and Migonemyia migonei (França, 1920) (9.1%). Leishmania amazonensis DNA was detected in Ny. whitmani (four pools) and Le. braziliensis DNA was detected in Psychodopygus lloydi (one pool). In seven pools of Ny. whitmani and in one pool of Lu. longipalpis positive for Leishmania DNA, the parasite species was not determined due to the low quality of the sequences. Moreover, DNA of Herpetomonas spp. was detected in Ny. whitmani (two pools) and Cortelezzii complex (one pool). DNA of Crithidia spp. was detected in Ny. whitmani and Ps. lloydi (both one pool). Our results suggest that Ny. whitmani may be involved in the transmission of Le. amazonensis in the study area. The molecular detection of Le. amazonensis suggests the presence of this species in a sylvatic cycle between vertebrate and invertebrate hosts in the region of Casa Branca. Our data also reveal the occurrence of other non-Leishmania trypanosomatids in sand flies in Casa Branca District.


Asunto(s)
Biodiversidad , Insectos Vectores/parasitología , Leishmania/aislamiento & purificación , Phlebotomus/parasitología , Psychodidae/parasitología , Animales , Brasil/epidemiología , ADN Protozoario/aislamiento & purificación , Enfermedades Endémicas/prevención & control , Femenino , Humanos , Leishmania/genética , Leishmaniasis/epidemiología , Leishmaniasis/parasitología , Leishmaniasis/prevención & control , Leishmaniasis/transmisión , Análisis de Secuencia de ADN
4.
Carbohydr Polym ; 237: 116120, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-32241437

RESUMEN

Leishmania is an obligate intracellular pathogen that invades phagocytic host cells. Due to its high morbidity and mortality rates, leishmaniasis attracts significant attention. The disease, which is caused by Leishmania parasites, is distributed worldwide, particularly among developing communities, and causes fatal complications if not treated expediently. Unfortunately, the existing treatments are not preventive and do not impede Leishmania infection. Many drugs available for leishmaniasis are becoming less effective due to emerging resistance in some Leishmania species. Other drugs have drawbacks such as low cost-effectiveness, toxicity, and side effects. The World Health Organization (WHO) considers leishmaniasis to be a major public health problem and suggests that the best prevention is to develop a vaccine for this dangerous disease. In this review, we focus on the unique components of lipophosphoglycan (LPG), a component of the Leishmania cell wall, particularly [Galp(1 → 4)-ß-[Manp-(1 → 2)-α-Manp-(1 → 2)-α]-Manp] in the cryptic tetrasaccharide cap, and on synthetic approaches as a potent candidate for a leishmaniasis vaccine.


Asunto(s)
Glicoproteínas/química , Glicoesfingolípidos/química , Leishmania/química , Leishmaniasis/parasitología , Humanos , Leishmaniasis/prevención & control , Vacunas contra la Leishmaniasis
5.
Pediatr. aten. prim ; 22(85): 49-53, ene.-mar. 2020. graf
Artículo en Español | IBECS | ID: ibc-193444

RESUMEN

En los últimos 25 años se ha producido un aumento global de casos de leishmaniasis. Se postula que el cambio climático, el aumento global de la temperatura, las migraciones masivas del campo a la ciudad y los proyectos agroindustriales (creación de pantanos, sistemas de riego, formación de pozos...) potencian la aparición de reservorios de mosquitos flebotomos, que son los vectores de esta enfermedad. Cabe destacar que en la Comunidad Valenciana, zona endémica, la tasa de incidencia ha sufrido un aumento considerable en los últimos años. Describimos a un paciente de dos años que presenta cuadro clínico y analítico compatible con leishmaniasis visceral (fiebre, esplenomegalia y pancitopenia) con el antecedente, varios meses antes, de leishmaniasis cutánea. Existen pocos casos en la literatura médica que describan una afectación cutánea y visceral concomitante, hecho que otorga importancia a nuestro caso. La inmadurez de la respuesta inmune celular a esa edad podría ser la causa de esta forma de presentación atípica


In the last 25 years there has been a global increase in cases of leishmaniasis. It is postulated that climate change, global increase in temperature, massive migrations from the countryside to the city and agro-industrial projects (creation of swamps, irrigation systems, water well formation...) enhance the emergence of reservoirs of sand-fly mosquitoes, which are the vectors of this disease. It should be noted that in the Valencian Community, an endemic area, the incidence rate has suffered a considerable increase in recent years. We describe a 2-year-old patient who presented clinical and analytical findings compatible with visceral leishmaniasis (fever, splenomegaly and pancytopenia), with the antecedent, several months before, of a cutaneous leishmaniasis. There are few cases in the literature that describe concomitant cutaneous and visceral leishmaniasis, a fact that gives importance to our case. The immaturity of the cellular immune response at that age could be the cause of this atypical presentation


Asunto(s)
Humanos , Femenino , Lactante , Leishmaniasis Cutánea/diagnóstico , Leishmania/patogenicidad , Leishmaniasis Visceral/diagnóstico , Diagnóstico Diferencial , Mosquitos Vectores/patogenicidad , Leishmaniasis/prevención & control , Convulsiones Febriles/etiología
6.
Trop Med Int Health ; 25(5): 540-557, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32034985

RESUMEN

Canine leishmaniosis is an important vector-borne zoonosis caused mainly by Leishmania infantum. Diagnosis and treatment of affected individuals can be particularly complex, hindering infection control in endemic areas. Methods to prevent canine leishmaniosis include the use of topical insecticides, prophylactic immunotherapy and vaccination. Four vaccines against canine leishmaniosis have been licensed since 2004, two in Brazil (Leishmune®, the production and marketing licence of which was withdrawn in 2014, and Leish-Tec®) and two in Europe (CaniLeish® and LetiFend®). After several years of marketing, doubts remain regarding vaccine efficacy and effectiveness, potential infectiousness of vaccinated and infected animals or the interference of vaccine-induced antibodies in L. infantum serological diagnosis. This review summarises the scientific evidence for each of the vaccines commercially approved for canine leishmaniosis, while discussing possible weaknesses of these studies. Furthermore, it raises the need to address important questions related to vaccination impact in Leishmania-endemic countries and the importance of post-marketing pharmacological surveillance.


Asunto(s)
Enfermedades de los Perros/prevención & control , Leishmaniasis/veterinaria , Animales , Anticuerpos Antiprotozoarios/sangre , Brasil , Comercio , Enfermedades de los Perros/sangre , Perros , Europa (Continente) , Leishmania infantum/inmunología , Leishmaniasis/prevención & control , Vigilancia de Productos Comercializados , Vacunación/veterinaria , Vacunas/efectos adversos
7.
Expert Opin Drug Deliv ; 17(2): 167-187, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31914821

RESUMEN

Introduction: Leishmaniasis is a neglected tropical infection caused by several species of intracellular protozoan parasites of the genus Leishmania. It is strongly believed that the development of vaccines is the most appropriate approach to control leishmaniasis. However, there is no vaccine available yet and the lack of an appropriate adjuvant delivery system is the main reason.Areas covered: Adjuvants are the utmost important part of a vaccine, to induce the immune response in the right direction. Limitations and drawbacks of conventional adjuvants have been necessitated the development of novel particulate delivery systems as adjuvants to obtain desirable protection against infectious diseases such as leishmaniasis. This review focused on particulate adjuvants especially nanoparticles that are in use to develop vaccines against leishmaniasis. The list of adjuvants includes generally lipids-, polymers-, or mineral-based delivery systems that target antigens specifically to the site of action within the host's body and enhance immune responses.Expert opinion: Over the past few years, there has been an increasing interest in developing particulate adjuvants as alternatives to immunostimulatory types. The composition of nano-carriers and particularly the physicochemical properties of nanoparticles have great potential to overcome challenges posed to leishmaniasis vaccine developments.


Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Portadores de Fármacos/administración & dosificación , Vacunas contra la Leishmaniasis/administración & dosificación , Leishmaniasis/prevención & control , Nanopartículas/administración & dosificación , Animales , Humanos
9.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(4): 353-355, 2019 Sep 24.
Artículo en Chino | MEDLINE | ID: mdl-31612666

RESUMEN

Following the concerted efforts for nearly 70 years, great achievements have been obtained in parasitic diseases control in China, and some important parasitic diseases have been eliminated or moving towards elimination in the country. With the socioeconomic development, the implementation of the "Road and Belt Initiative" and the increase in the international communication and overseas investment, there is a rise in the number of overseas labors, businessmen, students, travelers, visitors and participants in national and international communication activities, resulting in a gradual increase in the number of cases with parasitic diseases imported from endemic to non-endemic areas of China and from foreign countries to China. The increase in the number of imported cases causes new challenges for the elimination of parasitic diseases in China. The paper describes the current status of malaria, schistosomiasis and leishmaniasis, analyzes the challenges for the current control activities, and proposes the control strategies and interventions.


Asunto(s)
Leishmaniasis , Malaria , Esquistosomiasis , China/epidemiología , Enfermedades Transmisibles Importadas/epidemiología , Humanos , Leishmaniasis/epidemiología , Leishmaniasis/prevención & control , Malaria/epidemiología , Malaria/prevención & control , Factores de Riesgo , Esquistosomiasis/epidemiología , Esquistosomiasis/prevención & control
10.
Rev. salud pública ; 21(4): e374866, jul.-ago. 2019.
Artículo en Español | LILACS | ID: biblio-1127211

RESUMEN

RESUMEN La leishmaniosis continúa siendo un importante problema de salud pública pese a los esfuerzos gubernamentales, de grupos e individuos. Se estima que a nivel mundial se producen entre 50 000 y 90 000 casos nuevos de leishmaniosis visceral y entre 0.5 y 1 millón de leishmaniosis tegumentaria. Además, en algunas regiones esta parasitosis tiene carácter endemoepidémico, y en los últimos años ha incrementado su frecuencia y distribución. El objeto del presente escrito es mostrar algunas contribuciones de la epidemiología al control de la leishmaniosis, como resultado de la descripción y del análisis de la distribución y de los determinantes de esta parasitosis, extremadamente compleja en cuanto a transmisor, agente etiológico, reservorio y susceptible. Con base en la revisión de la literatura científica en el contexto de un estudio descriptivo, documental y retrospectivo se alcanzó el objetivo del presente escrito. Se concluye que es clara la utilidad de la epidemiología en el control de la leishmaniosis o, en todo caso, se reafirma el carácter válido y práctico de la epidemiología en el quehacer programático y operativo de la intervención en salud en el caso de la leishmaniosis.(AU)


ABSTRACT Leishmaniasis despite government efforts, groups and individuals continues to be a major public health problem, it is estimated that globally occur between 50 000 and 90 000 new cases of visceral leishmaniasis and between 0.5 and 1 million tegumentary leishmaniasis, plus in some regions, this parasitism has an endemo-epidemic nature, and in recent years its frequency and distribution have increased. The purpose of this paper is to show some contributions of epidemiology to the control of leishmaniasis, as a result of the description and analysis of the distribution and determinants of this parasitism, extremely complex in terms of transmitter, etiological agent, reservoir and susceptible. Based on the review of the scientific literature in the context of a descriptive, documentary and retrospective study, the objective of this paper was achieved. It is concluded that the usefulness of epidemiology in the control of leishmaniasis is clear or in any case reaffirms the validity and practicality of epidemiology in the programmatic and operational task of health intervention in the case of leishmaniasis.(AU)


Asunto(s)
Humanos , Parásitos , Leishmaniasis/prevención & control , Leishmaniasis/epidemiología , Vigilancia en Salud Pública
12.
Onderstepoort J Vet Res ; 86(1): e1-e11, 2019 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-31170780

RESUMEN

Canine leishmaniasis is a vector-borne disease caused by protozoa of the genus Leishmania that affect dogs, humans and wildlife. Sandflies of the genera Phlebotomus and Lutzomyia are the primary vectors. Canine leishmaniasis is an exotic and controlled disease in South Africa. The main purpose of our risk assessment study was to evaluate the likelihood that this exotic disease could enter and be established in South Africa through importation of live dogs. Risk analysis to the spread of the disease follows the World Organization for Animal Health (OIE) formal method of quantitative risk assessment documented as a step-by-step process. We have identified and discussed 11 possible risk factors involved in three steps for final assessment. The annual average number of diagnostic tests performed on imported dogs from 44 countries for 2011-2015 was 1158. Leishmania is reported to occur in 21/44 (47.7%) exporting countries. A total of 71.1% of Leishmania positive dogs were imported from these endemic countries. The yearly percentage of Leishmania positive dogs ranged from 0.2% to 2%. Three confirmed clinical and fatal cases of leishmaniasis in dogs of unidentified origin have been reported by our laboratory and the state veterinarians. The disease has been reported in neighbouring countries as well as the putative sandfly vectors. This study concluded that the risk for the introduction and degree of uncertainty of Leishmania in imported dogs in South Africa are moderate. Risk mitigation and recommendations such as investigations into possible occurrence of autochthonous leishmaniasis in the country, surveillance in its wildlife reservoirs and systematic surveillance of sandfly populations are discussed.


Asunto(s)
Enfermedades de los Perros/epidemiología , Leishmaniasis/veterinaria , Cuarentena/veterinaria , Animales , Enfermedades de los Perros/prevención & control , Enfermedades de los Perros/transmisión , Perros , Leishmaniasis/epidemiología , Leishmaniasis/prevención & control , Leishmaniasis/transmisión , Factores de Riesgo , Sudáfrica/epidemiología
13.
Clin Microbiol Infect ; 25(12): 1479-1483, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31212075

RESUMEN

BACKGROUND: Leishmaniasis and malaria are major causes of illness in the poorest countries. In the absence of efficient strategies to prevent infections and to control the transmission of the parasites by insect vectors, treatment relies on drug therapy. Vaccine development continues on several fronts; however none of the candidates developed has so far been shown to provide long-lasting protection at a population level. Because the bacillus Calmette-Guérin (BCG) vaccine can induce heterologous protective effects, we hypothesize that BCG has beneficial effects in the control of tegumentary leishmaniasis (TL) and malaria. AIMS: In this review we describe evidence for the protective efficacy of BCG against tegumentary leishmaniasis and malaria in humans. SOURCES: Relevant data from peer-reviewed scientific literature published on Pubmed up to January 2019 were examined. CONTENT: From experimental animal and various human studies with BCG and one recent randomized malaria trial there is evidence that BCG has beneficial effects in Leishmania spp. and Plasmodium falciparum infections. Although the precise mechanisms remain unknown, BCG can activate innate immune responses, and an increasing body of evidence demonstrates that the induction of trained innate immunity could explain its non-specific protective effects. IMPLICATIONS: Despite many years of research to prevent and treat TL and malaria, these diseases remain a public health problem in tropical countries. Future studies are required to examine if BCG vaccination could be used as an effective treatment option.


Asunto(s)
Vacuna BCG/administración & dosificación , Vacuna BCG/inmunología , Inmunidad Heteróloga/inmunología , Infecciones por Protozoos/tratamiento farmacológico , Animales , Humanos , Inmunidad Innata , Leishmaniasis/tratamiento farmacológico , Leishmaniasis/parasitología , Leishmaniasis/prevención & control , Malaria/tratamiento farmacológico , Malaria/parasitología , Malaria/prevención & control , Carga de Parásitos , Infecciones por Protozoos/parasitología , Infecciones por Protozoos/prevención & control , Vacunación
15.
Acta Parasitol ; 64(3): 645-651, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31111360

RESUMEN

PURPOSE: Leishmaniasis, as one of the most important vector-borne and zoonotic diseases, can be seen in different forms and is more prevalent in developing countries worldwide. Due to the absence of effective strategies in its prevention, treatment, and control, investigation of effective control strategies against the disease is necessary. In this research, we evaluated the immunogenicity of a cold-adapted laboratory strain of Leishmania major (LMC) in the mouse model. METHODS: Twenty BALB/c mice were divided into two groups. LMC group received 4 × 106 of LMC strain in 0.5 ml DMEM, and VLM group, as the control group, received 0.5 ml Dulbecco's modified Eagle's medium. Both groups were challenged with virulent L. major 3 weeks after inoculation. RESULTS: The data obtained from the analysis of immune responses and histopathological changes interestingly revealed protection against L. major in immunized mice. Compared with the VLM group, the mice immunized with LMC strain of L. major in the LMC group showed a significant increase in IFN-γ and IgG2a levels (P < 0.05) which are important indexes for Th1-related immune responses. Additionally, significant differences in concentration of IgG1 and IgG total before and after the challenge was observed in LMC group (P < 0.05). Furthermore, the immunized mice showed a significant reduction in mean sizes of skin lesion and liver damage compared to the VLM group. CONCLUSION: Based on the present findings on immunogenicity of LMC strain, it seems this strain is able to induce both humoral and cellular immunity and a significant protection against L. major in the mouse model.


Asunto(s)
Leishmania major/inmunología , Leishmaniasis/inmunología , Leishmaniasis/prevención & control , Animales , Anticuerpos Antiprotozoarios/inmunología , Femenino , Humanos , Inmunidad Celular , Inmunidad Humoral , Inmunización , Leishmania major/genética , Leishmaniasis/parasitología , Ratones , Ratones Endogámicos BALB C , Proteínas Protozoarias/administración & dosificación , Proteínas Protozoarias/genética , Proteínas Protozoarias/inmunología , Células TH1/inmunología
16.
Adv Parasitol ; 104: 1-38, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31030767

RESUMEN

Leishmania tropica causes different forms of leishmaniasis in many parts of the world. Animal models can help to clarify the issues of pathology and immune response in L. tropica infections and can be applied to the control, prevention and treatment of the disease. The aim of this article is to summarize published data related to experimental models of this parasite, presenting an overview of the subject. We also present in brief the epidemiology, transmission and human manifestation of L. tropica infection. Mice, rats and hamsters have been used for experimental models of L. tropica infection. Main findings of the published studies show that: (1) Hamsters are the best animal model for L. tropica infection, with the drawback of being outbred hence not suitable for many studies. (2) L. tropica infection causes a non-ulcerative and chronic pathology as cutaneous form in mice and usually visceral form in hamsters. (3) L. tropica infection in mice results in a weaker immune response in comparison to Leishmania major. (4) While the Th1 responses are evoked against L. tropica, Th2 responses do not explain the outcomes of this infection, and IL-10 and TGF-ß are two main suppressive cytokines. (5) The host genotype affects the immune response and disease outcome of L. tropica infection and the dose, strain, routes of inoculation, and sex of the host are among the factors affecting disease outcome of this species.


Asunto(s)
Interacciones Huésped-Parásitos , Leishmania tropica , Leishmaniasis , Animales , Modelos Animales de Enfermedad , Genotipo , Interacciones Huésped-Parásitos/genética , Interacciones Huésped-Parásitos/inmunología , Humanos , Leishmaniasis/inmunología , Leishmaniasis/prevención & control , Leishmaniasis/terapia , Leishmaniasis/transmisión , Factores Sexuales
17.
PLoS One ; 14(4): e0210681, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31022192

RESUMEN

BACKGROUND: Leishmaniasis caused by protozoan parasite Leishmania is a neglected disease which is endemic in the northwest of China. Reptiles were considered to be the potential reservoir hosts for mammalian Leishmaniasis, and Leishmania had been detected in lizards from the epidemic area in the northwest of China. To date, few studies are focused on the natural infection of snakes with Leishmania. METHODS: In this study, 15 snakes captured from 10 endemic foci in the northwest of China were detected Leishmania spp. on the base of mitochondrial cytochrome b, heat shock protein 70 gene and ribosomal internal transcribed spacer 1 regions, and identified with phylogenetic and network analyses. RESULT: In total, Leishmania gene was found in 7 snakes. The phylogenetic inference trees and network analysis suggests that the species identification was confirmed as Leishmania donovani, L. turanica and L. (Sauroleishmania) sp. CONCLUSION: Our work is the first time to investigate the natural Leishmania spp. infection of snakes in the northwest of China. Mammalian Leishmania (L. donovani and L. turanica) was discovered in snakes and the reptilian Leishmania (Sauroleishmania sp.) was closely related to the clinical strains both prompt the importance of snakes in the disease cycle. To indicate the epidemiological involvement of snakes, a wide sample size in epidemic area and the pathogenic features of reptilian Leishmania promastigotes are recommended in the future research.


Asunto(s)
Reservorios de Enfermedades/parasitología , Leishmania/genética , Leishmaniasis/parasitología , Enfermedades Desatendidas/parasitología , Serpientes/parasitología , Animales , China , ADN Protozoario/genética , ADN Protozoario/aislamiento & purificación , Enfermedades Endémicas/prevención & control , Humanos , Leishmania/aislamiento & purificación , Leishmaniasis/prevención & control , Leishmaniasis/transmisión , Enfermedades Desatendidas/prevención & control , Filogenia , Proteínas Protozoarias/genética , Análisis de Secuencia de ADN
18.
Molecules ; 24(8)2019 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-31010226

RESUMEN

Neglected tropical diseases affect the lives of a billion people worldwide. Among them, the parasitic infections caused by protozoan parasites of the Trypanosomatidae family have a huge impact on human health. Leishmaniasis, caused by Leishmania spp., is an endemic parasitic disease in over 88 countries and is closely associated with poverty. Although significant advances have been made in the treatment of leishmaniasis over the last decade, currently available chemotherapy is far from satisfactory. The lack of an approved vaccine, effective medication and significant drug resistance worldwide had led to considerable interest in discovering new, inexpensive, efficient and safe antileishmanial agents. 1,3,4-Thiadiazole rings are found in biologically active natural products and medicinally important synthetic compounds. The thiadiazole ring exhibits several specific properties: it is a bioisostere of pyrimidine or benzene rings with prevalence in biologically active compounds; the sulfur atom increases lipophilicity and combined with the mesoionic character of thiadiazoles imparts good oral absorption and good cell permeability, resulting in good bioavailability. This review presents synthetic 2-amino-1,3,4-thiadiazole derivatives with antileishmanial activity. Many reported derivatives can be considered as lead compounds for the synthesis of future agents as an alternative to the treatment of leishmaniasis.


Asunto(s)
Antiprotozoarios/uso terapéutico , Leishmaniasis/prevención & control , Tiadiazoles/uso terapéutico , Animales , Femenino , Humanos , Leishmania/efectos de los fármacos , Leishmania/patogenicidad , Masculino
20.
PLoS Negl Trop Dis ; 13(1): e0007111, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30695020

RESUMEN

BACKGROUND: Despite the known burden of neglected tropical diseases (NTDs) on child health, there is limited information on current efforts to increase pediatric therapeutic options. Our objective was to quantify and characterize research activity and treatment availability for NTDs in children in order to inform the prioritization of future research efforts. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a review of the World Health Organization's (WHO) International Clinical Trials Registry Platform to assess research activity for NTDs. The burden of disease of each NTD was measured in terms of disability adjusted life years (DALYs), which was extracted from the Global Health Data Exchange. First- and second-line medications for each NTD were identified from WHO guidelines. We reviewed FDA drug labels for each medication to determine whether they were adequately labeled for use in children. Descriptive statistics, binomial tests, and Spearman's rank order correlations were calculated to assess research activity compared to burden of disease. Children comprised 34% of the 20 million DALYs resulting from NTDs, but pediatric trials contributed just 17% (63/369) of trials studying these conditions (p<0.001 for binomial test). Conditions that were particularly under-represented in pediatric populations compared to adults included rabies, leishmaniasis, scabies, and dengue. Pediatric drug trial activity was poorly correlated with pediatric burden of disease across NTDs (Spearman's rho = 0.41, p = 0.12). There were 47 medications recommended by the WHO for the treatment of NTDs, of which only 47% (n = 22) were adequately labeled for use in children. Of the 25 medications lacking adequate pediatric labeling, three were under study in pediatric trials. CONCLUSIONS/SIGNIFICANCE: There is a substantial gap between the burden of disease for NTDs in children and research devoted to this population. Most medications lack adequate pediatric prescribing information, highlighting the urgency to increase pediatric research activity for NTDs with high burden of disease and limited treatment options.


Asunto(s)
Salud del Niño , Enfermedades Desatendidas/tratamiento farmacológico , Enfermedades Desatendidas/economía , Niño , Ensayos Clínicos como Asunto , Costo de Enfermedad , Dengue/tratamiento farmacológico , Dengue/economía , Dengue/prevención & control , Etiquetado de Medicamentos , Salud Global , Humanos , Leishmaniasis/tratamiento farmacológico , Leishmaniasis/economía , Leishmaniasis/prevención & control , Enfermedades Desatendidas/prevención & control , Rabia/tratamiento farmacológico , Rabia/economía , Rabia/prevención & control , Estados Unidos , Organización Mundial de la Salud
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