Expresión transcripcional de receptores tipo Toll y citoquinas proinflamatorias en macrófagos infectados con Leishmania braziliensis nativa / Transcriptional expression of Toll-like receptors and proinflammatory cytokines in macrophages infected with native Leishmania braziliensis

RESUMEN Introducción. El receptor de tipo Toll (TLR) que interactúe con el promastigote de Leishmania spp. determina la vía de activación celular. Objetivo. Identificar la expresión transcripcional de TLR-3, TLR-4, TLR-9, IL-12 y TNF-α en macrófagos infectados con una cepa nativa de L. braziliensis (Lbn). Métodos. La identificación de Lbn se hizo empleando qPCR para secuencias del DNA del cinetoplasto. Los macrófagos peritoneales de ratones fueron infectados con promastigotes y se midieron la producción de óxido nítrico (ON). Se cuantificaron los niveles transcripcionales para TLRs y citoquinas empleando qRT-PCR. Resultados. Lbn presentó 96% de homología con L. braziliensis. En los infectados con promastigotes se observó elevada producción de ON a las 2 h; significativa expresión transcripcional especialmente de TLR-3 y TLR-9 que se correspondió con la expresión para citoquinas. Conclusión. Lbn activó fuertemente a los macrófagos mediante los TLRs endosomales lo cual puede ser aplicado en el diseño de agonistas para tratar la enfermedad.

ABSTRACT Introduction. The Toll-like receptor (TLR) interacting with the promastigote of Leishmania spp. determines the cellular activation pathway. Objective. To determine the transcriptional expression of TLR-3, TLR-4, TLR-9, IL-12 and TNF-α in macrophages infected with a native strain of L. braziliensis (Lbn). Materials and Methods. Identification of Lbn was performed by qPCR for kinetoplast DNA sequences. Mouse peritoneal macrophages were infected with promastigotes (MI) and nitric oxide (NO) production was measured; transcript levels for TLRs and cytokines were quantified by qRT-PCR. Results. Lbn showed 96% homology to L. braziliensis. High ON production was observed in IMs at 2 h; significant transcriptional expression especially of TLR-3 and TLR-9, which corresponded with expression for cytokines. Conclusions. Lbn strongly activated macrophages via endosomal TLRs, which can be applied in the design of agonists to treat the disease.

Estudo estrutural e comparativo entre Sirtuínas 2 de diferentes espécies de Leishmania / Structural and comparative study between Sirtuins 2 of different species of Leishmania by means of Comparative Modeling and Molecular Dynamic

As leishmanioses são doenças negligenciadas que afetam mais de um bilhão e meio de pessoas ao redor do mundo, principalmente nos países em desenvolvimento, provocando grandes impactos socioeconômicos. Os fármacos disponíveis para o tratamento dessas doenças são ineficazes e apresentam graves efeitos adversos. O processo de pesquisa de novos fármacos envolve, entre outras coisas, a seleção de alvos bioquímicos essenciais para a sobrevivência e desenvolvimento do agente causador. Neste sentido, a Sirtuína 2, uma enzima epigenética com atividade hidrolase essencial para a sobrevivência dos parasitas do gênero Leishmania se apresenta como um alvo validado na busca de novos fármacos contra essas parasitoses. O planejamento de fármacos baseado na estrutura do receptor requer o conhecimento da estrutura tridimensional da proteína alvo. Desta forma, a elucidação estrutural e um estudo minucioso das Sirtuínas das várias espécies do gênero Leishmania apresenta-se como uma importante abordagem na aplicação desta estratégia na busca por agentes quimioterápicos. Até o momento, na família Trypanosomatidae, a única estrutura tridimensional resolvida experimentalmente de uma enzima Sirtuína 2 é a da espécie L. infantum. Assim, este trabalho aplicou a abordagem de Modelagem Comparativa utilizando o software Modeller na construção de modelos da Sir2rp1 das espécies L. infantum, L. major e L. braziliensis, cujas sequências de aminoácidos foram extraídas do banco de dados UNIProt. Os modelos construídos foram validados por meio da função de escore DOPE do Modeller e dos servidores PROCHECK, MolProbity e QMEAN, avaliando sua qualidade estereoquímica e seu enovelamento. Os ligantes naturais da enzima foram sobrepostos nos modelos construídos por alinhamento estrutural utilizando o software PyMol e os complexos validados foram submetidos a simulações de Dinâmica Molecular através do pacote GROMACS. Os complexos refinados foram então analisados por meio dos softwares PyMol e LigPlotPlus e dos pacotes GROMACS e gmx_MMPBSA, e foram estudados os sítios de ligação dos substratos e os resíduos de aminoácidos relevantes envolvidos em sua ligação e reconhecimento. A Modelagem Comparativa da Sirtuína 2 humana e seus homólogos das espécies L. infantum, L. major e L. braziliensis, as simulações de Dinâmica Molecular realizadas com os modelos enzimáticos construídos e validados complexados com seus ligantes naturais, os cálculos de energia de interação entre os modelos e seus substratos e o estudo estrutural comparativo realizado entre eles nos fornecem uma base teórica para a busca de novos inibidores da Sirtuína 2 que sejam mais seletivos e potentes contra as enzimas parasitárias, abrindo caminho para o desenvolvimento de candidatos a fármacos leishmanicidas mais seguros e eficazes

Leishmaniasis are neglected diseases that affect more than one and a half billion people around the world, mainly in developing countries, causing major socioeconomic impacts. The drugs available for the treatment of these diseases are ineffective and have serious adverse effects. The process of researching new drugs involves, among other things, the selection of biochemical targets essential for the survival and development of the causative agent. In this sense, Sirtuin 2, an epigenetic enzyme with hydrolase activity essential for the survival of parasites of the Leishmania genus, presents itself as a validated target in the search for new drugs against these parasites. Structure-Based Drug Design requires knowledge of the three-dimensional structure of the target protein. In this way, structural elucidation and a detailed study of Sirtuins from various species of the genus Leishmania presents itself as an important approach in the application of this strategy in the search for chemotherapeutic agents. To date, in the Trypanosomatidae family, the only experimentally resolved three-dimensional structure of a Sirtuin 2 enzyme is that of the species L. infantum. Thus, this work applied the Comparative Modeling approach using the Modeller software in the construction of Sir2rp1 models of the species L. infantum, L. major and L. braziliensis, whose amino acid sequences were retrieved from the UNIProt database. The constructed models were validated using Modeller's DOPE score function and the PROCHECK, MolProbity and QMEAN servers, evaluating their stereochemical quality and folding. The enzyme's natural ligands were superimposed on the built models by structural alignment using the PyMol software and the validated complexes were subjected to Molecular Dynamics simulations using the GROMACS package. The refined complexes were then analyzed using the PyMol and LigPlotPlus softwares and the GROMACS and gmx_MMPBSA packages, and the substrate binding sites and relevant amino acid residues involved in their binding and recognition were studied. The Comparative Modeling of human Sirtuin 2 and its homologues from the species L. infantum, L. major and L. braziliensis, the Molecular Dynamics simulations carried out with the constructed and validated enzymatic models complexed with their natural ligands, the interaction energy calculations between the models and their substrates and the comparative structural study carried out between them provide us with a theoretical basis for the search for new Sirtuin 2 inhibitors that are more selective and potent against the parasitic enzymes, paving the way for the development of safer and more effective leishmanicidal drug candidates

FVB/NJ strain as a mouse model for cutaneous leishmaniasis by Leishmania (L.) amazonensis

BACKGROUND Leishmaniases encompass a spectrum of neglected diseases caused by parasites of the genus Leishmania, grouped in two forms: tegumentary and visceral leishmaniasis. OBJECTIVES In this study, we propose Friend Virus B NIH Jackson (FVB/NJ) mouse strain as a new experimental model of infection with Leishmania (Leishmania) amazonensis, the second most prevalent agent of tegumentary leishmaniasis in Brazil. METHODS AND FINDINGS We performed in vitro infections of FVB/NJ macrophages and compared them with BALB/c macrophages, showing that BALB/c cells have higher infection percentages and a higher number of amastigotes/cell. Phagocytosis assays indicated that BALB/c and FVB/NJ macrophages have similar capacity to uptake parasites after 5 min incubations. We also investigated promastigotes' resistance to sera from FVB/NJ and BALB/c and observed no difference between the two sera, even though FVB/NJ has a deficiency in complement components. Finally, we subcutaneously infected FVB/NJ and BALB/c mice with 2 × 106 parasites expressing luciferase. Analysis of lesion development for 12 weeks showed that FVB/NJ and BALB/c mice have similar lesion profiles and parasite burdens. MAIN CONCLUSIONS This work characterises for the first time the FVB/NJ mouse as a new model for tegumentary leishmaniasis caused by Leishmania (L.) amazonensis.

The absence of eosinophils is associated with early metastatic lesions in Leishmania amazonensis-infected mice

BACKGROUND Eosinophils are granulocytes that rapidly increase frequency in the bloodstream during helminthic infections and allergic responses. They are found in tissue infected by Leishmania during early disease, but their role during infection is not entirely understood. OBJECTIVES We aim to compare the disease due to Leishmania amazonensis in BALB/c and Δdbl-GATA1 mice, which lack eosinophils. METHODS BALB/c and Δdbl-GATA1 mice infected with L. amazonensis were observed for several weeks. The parasite load and dissemination pattern were assessed. FINDINGS The Δdbl-GATA1 mice developed an anticipated dissemination of L. amazonensis and a worsening disease. No differences were found in the lesion development or the parasite load in the footpad among Δdbl-GATA1 mice and BALB/c eight weeks after infection. However, nine weeks after infection, massive growth of metastatic lesions appeared in several parts of the skin in Δdbl-GATA1 mice, weeks earlier than BALB/c. We observed increased parasites in the bloodstream, probably an essential dissemination route. Thirteen weeks after infection, metastatic lesions were found in all Δdbl-GATA1 mice. MAIN CONCLUSION These results suggest a protective role of eosinophils in delaying the disease caused by L. amazonensis, although several limitations of this mice strain must be considered.

GSK-3 kinase a putative therapeutic target in trypanosomatid parasites

ABSTRACT Trypanosomatids are an important group of parasites that predominate in tropical and subtropical areas of the planet, which cause diseases that are classified as forgotten and neglected by the world health organization. In this group of parasites, we find Trypanosoma cruzi, Trypanosoma brucei, Trypanosoma brucei rhodesiense and Leishmania spp, for which there is no vaccine available, and its control has focused mainly on pharmacological treatment. Due to the poverty situation where these diseases are found and the biological complexity of these parasites, there are multiple variables to control, including the diversity of species, the complexity of their life cycles, drug resistance, cytotoxicity, the limited use in pregnant women, the high costs of treatment and the little-known pharmacological mechanisms of action, among others. It is therefore necessary to find new strategies and approaches for the treatment of these parasitic diseases. Among these new approaches is the rational search for new targets based on the allosteric inhibition of protein kinases, which have been little studied in trypanosomatids. Among these kinases, we find Glycogen Synthase Kinase-3 (GSK-3), a kinase of great pharmacological interest, which is under intense basic and clinical research by pharmaceutical companies for the treatment of cancer. This kinase, highly studied in the PI3K/AKT/mTOR pathway signaling in humans, has an orthologous gene in these parasites (GSK-3 s), which has proven to be essential for them in response to different challenges; Therefore, it is notable to increase research in this kinase in order to achieve a broad structural and functional characterization in the different species of trypanosomatids.

Leishmania (Sauroleishmania) tarentolae versus pathogenic species: comparative evaluation of protease activity, glycoconjugates, resistance to complement and metabolome composition

BACKGROUND Leishmania tarentolae is a non-pathogenic species found in lizards representing an important model for Leishmania biology. However, several aspects of this Sauroleishmania remain unknown to explain its low level of virulence. OBJECTIVES We reported several aspects of L. tarentolae biology including glycoconjugates, proteolytic activities and metabolome composition in comparison to pathogenic species (Leishmania amazonensis, Leishmania braziliensis, Leishmania infantum and Leishmania major). METHODS Parasites were cultured for extraction and purification of lipophosphoglycan (LPG), immunofluorescence probing with anti-gp63 and resistance against complement. Parasite extracts were also tested for proteases activity and metabolome composition. FINDINGS Leishmania tarentolae does not express LPG on its surface. It expresses gp63 at lower levels compared to pathogenic species and, is highly sensitive to complement-mediated lysis. This species also lacks intracellular/extracellular activities of proteolytic enzymes. It has metabolic differences with pathogenic species, exhibiting a lower abundance of metabolites including ABC transporters, biosynthesis of unsaturated fatty acids and steroids, TCA cycle, glycine/serine/threonine metabolism, glyoxylate/dicarboxylate metabolism and pentose-phosphate pathways. MAIN CONCLUSIONS The non-pathogenic phenotype of L. tarentolae is associated with alterations in several biochemical and molecular features. This reinforces the need of comparative studies between pathogenic and non-pathogenic species to elucidate the molecular mechanisms of virulence during host-parasite interactions.

Estudo epidemiológico descritivo dos casos notificados de Leishmaniose visceral no estado de Goiás no período de 2011 a 2020 / Descriptive epidemiological study of notified cases of visceral Leishmaniasis in the state of Goiás in the period from 2011 to 2020 / Estudio epidemiológico descriptivo de los casos notificados de Leishmaniasis visceral en el estado de Goiás en el período de 2011 a 2020

A leishmaniose visceral, conhecida também como calazar, trata-se da forma mais grave das leishmanioses por ser uma enfermidade sistêmica e com um grande espectro clínico e um caráter irregular. Desse modo, objetivou-se avaliar a situação epidemiológica da leishmaniose visceral no Estado de Goiás, bem como o caráter dessa doença e o perfil mais atingido. Para isso, foi realizada uma pesquisa retrospectiva compreendendo o período de 2012 a 2021, com os casos notificados de leishmaniose visceral no Estado de Goiás. A busca pelos dados ocorreu por meio dos SINAN/DATASUS do Ministério da Saúde. Os dados encontrados foram tabulados e analisados por meio do programa Excel da Microsoft®. No período avaliado, foram notificados 388 casos de LV em Goiás, distribuídos em 47 municípios goianos. 66,23% das ocorrências pertenciam ao sexo masculino; 25,51% eram adultos com idade entre 20- 39 anos; 74,48% eram moradores da zona urbana; além disso, 9,27% do total de casos notificados em Goiás evoluíram para óbito. Há ainda uma a taxa de coinfecção LV/HIV de 12,11% do total de casos notificados. Constatou-se, portanto, que algumas localidades possuem registros consequentes de LV, levando a existência de áreas endêmicas no estado. Existe um perfil de acometimento em Goiás, no período de análise, direcionado para o sexo masculino, de cor parda, jovens adultos, com baixa escolaridade, vivendo nas cidades e grandes centros urbanos. Destaca-se o elevado quantitativo de dados identificados como ignorado/branco, que podem interferir significativmente em análises epidemiológicas.

Visceral leishmaniasis, also known as kala-azar, is the most serious form of leishmaniasis because it is a systemic disease with a wide clinical spectrum and an irregular character. Thus, the objective was to evaluate the epidemiological situation of visceral leishmaniasis in the State of Goiás, as well as the character of this disease and the most affected profile. For this, a retrospective survey was carried out covering the period from 2012 to 2021, with reported cases of visceral leishmaniasis in the State of Goiás. The search for data took place through the SINAN/DATASUS of the Ministry of Health. The data found were tabulated and analyzed using the Microsoft® Excel program. In the period evaluated, 388 cases of VL were reported in Goiás, distributed in 47 munic- ipalities in Goiás. 66.23% of the occurrences were male; 25.51% were adults aged be- tween 20-39 years; 74.48% were residents of the urban area; in addition, 9.27% of the total cases reported in Goiás evolved to death. There is also a LV/HIV co-infection rate of 12.11% of the total reported cases. It was found, therefore, that some localities have consequent records of VL, leading to the existence of endemic areas in the state. There is a profile of involvement directed towards males, of mixed race, young adults, with low education, living in cities and large urban centers. The high quantity of data identified as ignored/white stands out, which can significantly interfere in epidemiological analyses. KEYWORDS: Epidemiology; Leishmania; Notification.

La leishmaniasis visceral, también conocida como kala-azar, es la forma más grave de leishmaniasis por tratarse de una enfermedad sistémica de amplio espectro clínico y carácter irregular. Así, el objetivo fue evaluar la situación epidemiológica de la leishmaniasis visceral en el Estado de Goiás, así como el carácter de esta enfermedad y el perfil más afectado. Para ello, se realizó una encuesta retrospectiva que abarcó el período de 2012 a 2021, con los casos notificados de leishmaniasis visceral en el Estado de Goiás. La búsqueda de datos se realizó a través del SINAN/DATASUS del Ministerio de Salud. Los datos encontrados fueron tabulados y analizados utilizando el programa Microsoft® Excel. En el período evaluado, fueron notificados 388 casos de LV en Goiás, distribuidos en 47 municipios de Goiás. 66,23% de las ocurrencias fueron del sexo masculino; 25,51% eran adultos con edad entre 20-39 años; 74,48% eran residentes del área urbana; además, 9,27% del total de casos notificados en Goiás evolucionaron a muerte. Existe también una tasa de coinfección LV/VIH de 12,11% del total de casos notificados. Se constató, por lo tanto, que algunas localidades tienen registros consecuentes de LV, llevando a la existencia de áreas endémicas en el estado. Existe un perfil de envolvimiento dirigido a hombres, mestizos, adultos jóvenes, con baja escolaridad, residentes en ciudades y grandes centros urbanos. Se destaca la elevada cantidad de datos identificados como ignorados/blancos, lo que puede interferir significativamente en los análisis epidemiológicos.

Epidemiological aspects of American and visceral cutaneous leishmaniasis in the city of Cametá, Pará, Amazon / Aspectos epidemiológicos da leishmaniose tegumentar americana e visceral na cidade de Cametá, Pará, Amazônia / Aspectos epidemiológicos de la leishmaniasis cutánea americana y visceral en la ciudad de Cametá, Pará, Amazonas

Background and objectives: leishmaniases are anthropozoonosis considered a major public health problem in tropical regions and endemic in some areas of constant expansion. This study aimed to assess the main epidemiological aspects of American tegumentary leishmaniasis (ATL) and visceral leishmaniasis (VL) in the municipality of Cametá, in the state of Pará, from 2007 to 2017. Methods: this is a descriptive-exploratory analysis, of time series, with data collected in the Department of Epidemiological Surveillance of the Department of Sanitary Surveillance of Cametá. Statistical calculations were performed, and, for the coefficient of incidence of ATL and VL, the standard formula was used to obtain the indicator. Results: a total of 94 and 294 cases of ATL and VL were reported, with the highest incidence rate in 2008. The disease affected all established age groups, with high frequency in children under ten years of age for VL (n=174), and between 20 and 30 years of age, for ATL (n=71). The disease was more prevalent in males (ATL (89.4%) and VL (58.2%)), because men are more related to economic activities. Conclusion: considering the high number of rural cases, it is noteworthy that reporting in urban areas is also worrisome, in addition to the livelihood of local families, because it has made them vulnerable to the disease. Furthermore, there is concern about the possible expansion and change in the pattern of ATL in the municipality. The Municipal Department as well as the epidemiological surveillance must pay attention to promote investments and campaigns to combat and treat this important disease.(AU)

Justificativa e objetivos: as leishmanioses são antropozoonoses consideradas um grande problema para a saúde pública em regiões tropicais e endêmicas em algumas áreas de constante expansão. Este estudo teve como objetivo avaliar os principais aspectos epidemiológicos da leishmaniose tegumentar americana (LTA) e leishmaniose visceral (LV) no município de Cametá, no estado do Pará, no período de 2007 a 2017. Métodos: trata-se de uma análise descritiva-exploratória, de série temporal, com dados coletados no Departamento de Vigilância Epidemiológica da Secretaria de Vigilância Sanitária de Cametá. Realizaram-se os cálculos estatísticos, e, para o coeficiente de incidência de LTA e LV, utilizou-se a fórmula padrão para a obtenção do indicador. Resultados: foram notificados 94 e 294 casos de LTA e LV, com maior taxa de incidência em 2008. A doença atingiu todas as faixas etárias estabelecidas, com alta frequência nos menores de dez anos para LV (n=174), e, entre 20 e 30 anos de idade, para LTA (n=71). A doença foi mais prevalente no sexo masculino (LTA (89,4%) e LV (58,2%)), em virtude dos homens estarem mais relacionados com as atividades econômicas. Conclusão: em vista do alto número de casos rurais, ressalta-se que a notificação em área urbana também é preocupante, além dos meios de subsistência das famílias locais, pois vem tornando-as vulneráveis para o adoecimento. Ademais, há a preocupação com a possível expansão e mudança no padrão da LTA no município. A Secretaria Municipal, bem como de vigilância epidemiológica, deve atentar-se a promover investimentos e campanhas de combate e tratamento deste importante agravo.(AU)

Justificación y objetivos: las leishmaniasis son antropozoonosis consideradas un importante problema de salud pública en las regiones tropicales y endémicas en algunas zonas de constante expansión. Este estudio tuvo como objetivo evaluar los principales aspectos epidemiológicos de la leishmaniasis tegumentaria americana (LTA) y la leishmaniasis visceral (LV) en el municipio de Cametá, en el estado de Pará, de 2007 a 2017. Métodos: se trata de un análisis descriptivo-exploratorio, de serie temporal, con datos recolectados en el Departamento de Vigilancia Epidemiológica de la Secretaría de Vigilancia Sanitaria de Cametá. Se realizaron cálculos estadísticos y, para el coeficiente de incidencia de LCA y LV, se utilizó la fórmula estándar para obtener el indicador. Resultados: se reportaron 94 y 294 casos de LTA y LV, con la mayor tasa de incidencia en 2008. La enfermedad afectó a todos los grupos de edad establecidos, con alta frecuencia en menores de diez años para LV (n=174), y entre 20 y 30 años. años de edad, para LTA (n=71). La enfermedad fue más prevalente en el sexo masculino (LTA (89,4%) y VL (58,2%)), debido a que los hombres están más relacionados con actividades económicas. Conclusión: dado el alto número de casos rurales, cabe señalar que la notificación en las zonas urbanas también es motivo de preocupación, además de los medios de subsistencia de las familias locales, ya que las ha vuelto vulnerables a la enfermedad. Además, existe preocupación por la posible expansión y cambio en el patrón de LTA en el municipio. La Secretaría Municipal, así como la de vigilancia epidemiológica, debe prestar atención a promover inversiones y campañas para combatir y tratar este importante problema.(AU)

Conocimientos, actitudes y prácticas sobre Leishmaniasis visceral en tres comunas de Neiva, Huila

Introducción: La leishmaniasis visceral es una enfermedad zoonótica, transmitida por vectores del género Lutzomyia, de distribución en 98 países, incluyendo Colombia y que puede ocasionar un cuadro clínico grave, que en ausencia de tratamiento puede ser fatal. Objetivo: Determinar los conocimientos, actitudes y prácticas (CAP) adquiridas sobre vectores, reservorios y características de la Leishmaniasis visceral en las comunas 8, 9 y 10 de Neiva (Huila) en 2019. Materiales y métodos: Se realizó un estudio descriptivo de corte transversal en el período de junio a diciembre de 2019, en el que se muestrearon tres comunas (8, 9 y 10), en un total de 30 barrios de la ciudad de Neiva-Huila. Se aplicaron 385 encuestas tipo CAP, con un margen de error de 5 % y una confiabilidad de 95 %. Se incluyeron personas adultas de 18 años o más (267 mujeres y 117 hombres), que voluntariamente desearon participar, con previo consentimiento informado. Resultados: Según la información analizada, se determinó que 77 % de los encuestados no conoce la leishmaniasis visceral, 52 % no la identifican como una enfermedad zoonótica, 82 % no conocen el agente causal y 44 % no tienen claridad sobre los síntomas que se presentan en humanos. Conclusiones: Aunque se han realizado campañas preventivas en las comunas afectadas, el nivel de conocimiento sobre la enfermedad, el vector, el reservorio y las prácticas preventivas específicas para contrarrestar la leishmaniasis visceral son poco conocidos en la población de estudio, a pesar de que las prácticas y actitudes identificadas son positivas.

Introduction: Visceral leishmaniasis is a zoonotic disease transmitted by vectors of the Lutzomyia genus, distributed in 98 countries, including Colombia, which can cause a serious clinical picture that, in the absence of treatment, can be fatal. Objective: To determine the knowledge, attitudes, and practices (KAP) acquired on vectors and reservoirs, as well as the characteristics of visceral Leishmaniasis in communes 8, 9 and 10 of the city of Neiva in 2019. Material and Methods: A descriptive cross-sectional study was carried out from June to December 2019. Three communes (8, 9 y 10) were sampled from a total of 30 neighborhoods of the city of Neiva - Huila. In addition, 385 CAP-type surveys were applied, with a margin of error of 5% and a reliability of 95%. People aged 18 years or older (267 women and 117 men) who voluntarily wished to participate, with prior informed consent, were included. Results: According to the analyzed information, it was determined that the majority of the surveyed population did not know about visceral leishmaniasis (77%), did not identify it as a zoonotic disease (52%), nor did they know who the causative agent is (82%); furthermore, they were not clear about the symptoms that occur in humans, nor the treatment used to manage them. Conclusions: Although preventive campaigns have been carried out in the affected communes, the level of knowledge about the disease, the vector, the reservoir, and the specific preventive practices to counteract visceral leishmaniasis are little known in the study population, despite the fact that the identified practices and attitudes are positive.

Uso de anfotericina B liposomal en leishmaniasis cutánea diseminada causada por Leishmania braziliensis en un paciente pediátrico con síndrome de Down / Use of liposomal anfotericin B in diseminated cutaneous leishmaniasis caused by Leishmania braziliensis in a pediatric patient with Down syndrome

Se presenta un caso de leishmaniasis selvática cutánea diseminada con manifestación extensa en una paciente pediátrica con síndrome de Down. El caso se confirmó a través de estudios parasitológicos e inmunológicos, mientras que la identificación se realizó mediante la técnica de reacción en cadena de la polimerasa-polimorfismos de longitud de fragmentos de restricción (PCR-RFLP, por sus siglas en inglés), determinándose la especie como Leishmania (Viannia) braziliensis. La manifestación clínica agresiva y prolongada con poca respuesta a estibogluconato y anfotericina desoxicolato pueden deberse al déficit inmunológico que se presenta como parte del síndrome de Down. La paciente eventualmente recibió tratamiento con anfotericina B liposomal y al término de la terapia, mostró mejoría clínica de las lesiones. El presente reporte ilustra los desafíos tanto de diagnóstico como tratamiento de leishmaniasis cutánea en pacientes pediátricos inmunosuprimidos, especialmente en un entorno de difícil acceso social, económico y geográfico, a los servicios de salud. Se recomienda considerar a la leishmaniasis en el diagnóstico diferencial cuando se atienda ulceras crónicas dermatológicas atípicas; así como tener en cuenta el uso de anfotericina liposomal en pacientes inmunocomprometidos.

We present a case of disseminated cutaneous leishmaniasis with extensive manifestation in a pediatric patient with Down syndrome. The case was confirmed by parasitological and immunological tests. The species was identified as Leishmania (Viannia) braziliensis by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). The immune deficit that occurs as part of Down syndrome may have been the reason for the aggressive and prolonged clinical manifestations as well as the poor response to stibogluconate and deoxycholate amphotericin. The patient was treated with liposomal amphotericin B and at the end of therapy, showed clinical improvement of the lesions. This report highlights the challenges of the diagnosis and treatment of cutaneous leishmaniasis in immunosuppressed pediatric patients, especially under difficult social, economic and geographic conditions. Leishmaniasis should be considered as a differential diagnosis when treating atypical chronic dermatologic ulcers; the use of liposomal amphotericin in immunocompromised patients should also be considered in these cases.

Expression profile in Leishmania major exposed to Staphylococcus aureus and group A beta-hemolytic Streptococcus

Background & objectives: The interaction of Leishmania spp. with microbiota inside the midgut vector has significant output in pathogenesis. This study aimed to identify the profile of Leishmania major gene expression of LACK, gp63, and hsp70 after exposure to Staphylococcus aureus and group A beta-hemolytic Streptococci (GABHS). Methods: Leishmania major (MRHO/IR/75/ER) promastigotes were exposed with S. aureus, with GABHS, and with both GABHS and S. aureus at 25°C for 72 h. The gene expression analysis of Lmgp63, Lmhsp70, and LmLACK was assessed using SYBR Green real-time PCR by ??Ct. All experiments were repeated in triplicate. Statistical analysis was done using two-way ANOVA. A P-value less than 0.05 was considered significant. Results: Lmgp63 was expressed in the group exposed to GABHS with 1.75-fold lower than the control group (p=0.000). The LmLACK had expression in both groups exposed with GABHS and GABHS with S. aureus with 2.8 and 1.33-fold more than the control group, respectively (p=0.000). The Lmhsp70 gene expression was reported in the group exposed with GABHS with relative quantification of 5.7-fold more than the control group. Interpretation & conclusion: This study showed that the important genes encoding LACK, gp63, and hsp70 changed their expression after exposure to the S. aureus and GABHS.

Seleção de antígenos de Leishmania infantum por imunoproteômica para emprego no diagnóstico da leishmaniose visceral humana / Selection of Leishmania infantum antigens by immunoproteomics for use in the diagnosis of human visceral leishmaniasis

O controle da leishmaniose visceral (LV) requer um diagnóstico e tratamento adequados, uma vez que o diagnóstico preciso é fundamental para um regime medicamentoso eficaz para os pacientes. Nesse contexto, as ferramentas biotecnológicas devem ser aprimoradas para o manejo clínico e a avaliação epidemiológica da doença. No entanto, existem limitações relacionadas com a sensibilidade e/ou especificidade dos antígenos usados atualmente, mostrando a necessidade de identificação de novas moléculas para serem testadas em um diagnóstico sorológico mais sensível e específico. Neste sentido, no presente estudo, uma abordagem imunoproteômica foi usada para identificar proteínas antigênicas das formas promastigotas e amastigotas da espécie Leishmania infantum, causadora de LV em nosso país, por meio de seu reconhecimento por anticorpos em soros de pacientes com a doença. Amostras de indivíduos saudáveis residentes em região endêmica da doença e de pacientes com Doença de Chagas foram utilizadas com a função de se obter proteínas mais específicas ao parasito Leishmania para serem avaliadas no diagnóstico da LV. Como resultados obtidos, um total de 29 e 21 proteínas foram identificadas nos extratos de formas promastigotas e amastigotas dos parasitos, respectivamente. Para a validação da capacidade diagnóstica, duas proteínas, endonuclease III e GTP-binding protein, foram selecionadas, clonadas, expressas e purificadas para serem testadas em experimentos de ELISA. Os resultados dos testes mostraram valores de sensibilidade e especificidade superiores a 99,0% para a identificação da LV. Os antígenos ainda exibiram um diferencial ao apresentarem baixa reatividade sorológica em pacientes curados e tratados, sugerindo a possibilidade de que as mesmas possam ser aplicadas como marcadores prognósticos da doença. Em conclusão, o estudo imunoproteômico se mostrou eficaz na seleção de proteínas antigênicas de L. infantum e duas delas, endonuclease III e GTP-binding protein, foram bem avaliadas para o diagnóstico da LV frente a um painel sorológico, além de demonstrarem um potencial para monitoramento de pacientes com LV após o tratamento.

The control of visceral leishmaniasis (VL) requires an adequate diagnosis and treatment, since an accurate diagnosis is essential for an effective medication regimen for patients. In this context, biotechnological tools must be improved for the clinical management and epidemiological assessment of the disease. However, there are limitations related to the sensitivity and / or specificity of the antigens currently used, showing the necessity to identify new molecules to be tested in a more sensitive and specific serological diagnosis. In this sense, in the present study, an immunoproteomics approach was used to identify antigenic proteins of the Leishmania infantum promastigote and amastigote forms, which causes VL in our country, through its recognition by antibodies in sera of patients with the disease. Samples from healthy individuals living in an endemic region of the disease and from patients with Chagas disease were used to obtain more specific proteins for the Leishmania parasite, aiming their future application in the VL diagnosis. As results obtained, a total of 29 and 21 proteins were identified in the extracts of parasitic promastigotes and amastigotes, respectively. For validation of the diagnostic capacity, two proteins, endonuclease III and GTP-binding protein, were selected, cloned, expressed and purified to be tested in ELISA experiments. The test results showed sensitivity and specificity values greater than 99.0% for the identification of VL. The antigens also exhibited a differential when presenting low serological reactivity in cured and treated patients, suggesting the possibility that they can be applied as prognostic markers of the disease. In conclusion, the immunoproteomic study proved to be effective in the selection of L. infantum antigenic proteins and two of them, endonuclease III and GTP-binding protein, were well evaluated for the diagnosis of VL against a serological panel, in addition, demonstrating a potential for monitoring patients with VL after treatment.

Can domestic dogs be considered a good reservoir of Leishmania (L.) infantum chagasi in an endemic area of nonulcerated cutaneous leishmaniasis in Southern Honduras?

ABSTRACT Dogs are considered to be the main domestic reservoir associated with the transmission of Leishmania (L.) infantum chagasi to humans in endemic areas of visceral leishmaniasis in America. However, little is known about the role of canines as a source of infection in endemic areas of nonulcerated cutaneous leishmaniasis (NUCL). Therefore, the objective of the present study was to investigate the role of dogs as a possible reservoir of the parasite in Southern Honduras. Dogs (n = 107) living with individuals affected by NUCL were clinically examined and biological material was collected for parasitological and immunological diagnosis. Most animals showed a healthy appearance and a few presented slight weight loss (64%), alopecia (7%), onychogryphosis (5%) and skin lesions (1%). The overall seroprevalence of Leishmania infection based on the DDP ® quick test and/or in-house ELISA serological test was 41%. The presence of the parasite's DNA was confirmed in 94% of the dogs; however, the average parasite load in the buffy coat was low at 6.09 parasites/µL, ranging between 0.221 and 50.2. The skin of seropositive dogs examined by histopathology using paraffin sections stained by hematoxylin and immunohistochemistry did not show cutaneous lesions or parasite amastigotes. Based on the absence of parasites in the skin and the low parasite load detected in the buffy coat, it seems that the dog does not represent a good source of infection for the vector in the endemic area of NUCL transmission in Southern Honduras. Other domestic and/or wild animals should be investigated.

Blood parasite load by qPCR as therapeutic monitoring in visceral leishmaniasis patients in Brazil: a case series study

ABSTRACT Background: This study aimed to describe the kinetics of Leishmania parasite load determined using kinetoplast DNA (kDNA)-based quantitative polymerase chain reaction (qPCR) in visceral leishmaniasis (VL) patients. Methods: Parasite load in blood was assessed by qPCR at five time points, up to 12 months post-diagnosis. Sixteen patients were followed up. Results: A significant reduction in the parasite load was observed after treatment (P < 0.0001). One patient had an increased parasite load 3 months post-treatment and relapsed clinically at month six. Conclusions: We have described the use of kDNA-based qPCR in the post-treatment follow-up of VL cases.

First report of Leishmania (Mundinia) martiniquensis in South American territory and confirmation of Leishbunyavirus infecting this parasite in a mare

BACKGROUND Epidemiological data related to leishmaniases or Leishmania infection in horses are scarce. However, studies carried out in different regions in the world showed equids parasitised by Leishmania braziliensis, L. infantum and L. martiniquensis. OBJECTIVES Identify the Leishmania species causing cutaneous leishmaniasis in a mare, living in Rio de Janeiro State (Brazil), and search the presence of Leishmania viruses in the isolated parasite. METHODS Isoenzymes and polymerase chain reaction (PCR) targeting ITSrDNA region followed by sequencing were conducted for typing the isolated parasite. A search for Leishmania virus infection was also performed. FINDINGS The mare presented skin nodules and ulcers in the left pinna caused by Leishmania spp. that was detected by culture and PCR. The parasite was identified as Leishmania (Mundinia) martiniquensis, infected by Leishbunyavirus (LBV), representing the first description of this species in South America. The animal travelled to different Brazilian regions, but not to outside the country. MAIN CONCLUSIONS The worldwide distribution of L. martiniquensis and its infection by LBV were confirmed in this study, indicating the autochthonous transmission cycle in Brazil. The clinical profile of the disease in the mare, showing fast spontaneous healing of cutaneous lesions, may indicate that skin lesions related to L. martiniquensis infection in horses might be underdiagnosed.

Genetic variability of Leishmania (Leishmania) infantum causing human visceral leishmaniasis in the Southeastern Brazil

ABSTRACT Leishmania infantum is a protozoan that causes visceral leishmaniasis (VL) in the Americas and some regions of Europe. The disease is mainly characterized by hepatosplenomegaly and fever, and can be fatal. Factors related to the host and parasite can contribute to the transmission of Leishmania and the clinical outcome. The intraspecific genetic variability of L. infantum strains may be one of these factors. In this study, we evaluated the genetic variability of L. infantum obtained from bone marrow smear slides from patients in the Sao Paulo State, Brazil. For this, the minicircle of the kDNA hypervariable region was used as target by Sanger sequencing. By analyzing the similarity of the nucleotides and the maximum likelihood tree (Fasttree), we observed a high similarity (98%) among samples. Moreover, we identified four different profiles of L. infantum. In conclusion, L. infantum strains from Sao Paulo State, Brazil, showed low diversity measured by minicircle of the kDNA hypervariable region.

First report of putative Leishmania RNA virus 2 (LRV2) in Leishmania infantum strains from canine and human visceral leishmaniasis cases in the southeast of Brazil

BACKGROUND Leishmania RNA virus 1 (LRV1) is commonly found in South American Leishmania parasites belonging to the subgenus Viannia, whereas Leishmania RNA virus 2 (LRV2) was previously thought to be restricted to the Old-World pathogens of the subgenus Leishmania. OBJECTIVES In this study, we investigated the presence of LRV2 in strains of Leishmania (L.) infantum, the causative agent of visceral leishmaniasis (VL), originating from different hosts, clinical forms, and geographical regions. METHODS A total of seventy-one isolates were screened for LRV2 using semi-nested reverse transcription-polymerase chain reaction (RT-PCR) targeting the RNA-dependent RNA polymerase (RdRp) gene. FINDINGS We detected LRV2 in two L. infantum isolates (CUR268 and HP-EMO) from canine and human cases, respectively. MAIN CONCLUSIONS To the best of our knowledge, this is the first detection of LRV2 in the New World.

Natural infection of Lutzomyia longipalpis (Lutz & Neiva, 1912) by Leishmania infantum in a municipality with a high incidence of visceral leishmaniasis in the Brazilian Midwest

ABSTRACT Background: Here, Leishmania presence in sand flies from Três Lagoas, Mato Grosso do Sul, Brazil, after visceral leishmaniasis (VL) was investigated. Methods: In April 2022, two light traps were deployed within and around the residence for two days post-VL case report. Results: A total of 120 Lutzomyia longipalpis were collected. Suprapyloric flagellates were found in a female sand fly with eggs and residual blood during midgut dissection. Sequencing of ITS1 and cytb fragments confirmed Leishmania infantum DNA and identified Homo sapiens as the blood source, respectively. Conclusions: This study emphasizes the importance of monitoring sand flies in VL endemic areas.

Polyunsaturated fatty acids alter the formation of lipid droplets and eicosanoid production in Leishmania promastigotes

BACKGROUND The knowledge about eicosanoid metabolism and lipid droplet (LD) formation in the Leishmania is very limited and new approaches are needed to identify which bioactive molecules are produced of them. OBJECTIVES Herein, we compared LDs and eicosanoids biogenesis in distinct Leishmania species which are etiologic agents of different clinical forms of leishmaniasis. METHODS For this, promastigotes of Leishmania amazonensis, L. braziliensis and L. infantum were stimulated with polyunsaturated fatty acids (PUFA) and LD and eicosanoid production was evaluated. We also compared mutations in structural models of human-like cyclooxygenase-2 (GP63) and prostaglandin F synthase (PGFS) proteins, as well as the levels of these enzymes in parasite cell extracts. FINDINGS PUFAs modulate the LD formation in L. braziliensis and L. infantum. Leishmania spp with equivalent tissue tropism had same protein mutations in GP63 and PGFS. No differences in GP63 production were observed among Leishmania spp, however PGFS production increased during the parasite differentiation. Stimulation with arachidonic acid resulted in elevated production of hydroxyeicosatetraenoic acids compared to prostaglandins. MAIN CONCLUSIONS Our data suggest LD formation and eicosanoid production are distinctly modulated by PUFAS dependent of Leishmania species. In addition, eicosanoid-enzyme mutations are more similar between Leishmania species with same host tropism.

In vitro effects of lapachol and β-lapachone against Leishmania amazonensis

Leishmaniasis is a neglected disease that affects millions of people worldwide, and special attention should be given to treatment because the available drugs have limitations, which can lead to low therapeutic adherence and parasitic resistance. This study evaluated the activity of the bioactive naphthoquinones, lapachol and β-lapachone, against Leishmania amazonensis. The cell alterations were evaluated in vitro on promastigote and amastigote forms. The lethal dose (LD50) at 24, 48, and 72 h on the promastigote's forms using lapachol was 75.60, 72.82, and 58.85 μg/mL and for β-lapachone was 0.65, 1.24, and 0.71 μg/mL, respectively. The naphthoquinones significantly inhibited the survival rate of L. amazonensis amastigotes at 83.11, 57.59, and 34.95% for lapachol (82.28, 41.14, and 20.57 µg/mL), and 78.49, 83.25, and 80.22% for β-lapachone (3.26, 1.63, and 0.815 µg/mL). The compounds on the promastigote's forms led to the loss of mitochondrial membrane potential, induced changes in the integrity of the membrane, caused damage to cells suggestive of the apoptotic process, and showed inhibition of tumor necrosis factor (TNF)-α and interleukin (IL)-6 production. The results showed that these naphthoquinones are promising candidates for research on new drugs with anti-Leishmania activity derived from natural products.