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.

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.

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)

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.

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.

Chemical composition, in vitro larvicidal and antileishmanial activities of the essential oil from Citrus reticulata Blanco fruit peel / Composição química, atividades larvicida e leishmanicida in vitro do óleo essencial da casca do fruto de Citrus reticulata Blanco

Abstract Numerous studies have investigated the chemical composition and biological activities of essential oils from different Citrus species fruit peel, leaves and flowers. This paper aims to investigate the chemical composition, larvicidal and antileishmanial activities of essential oil from Citrus reticulata fruit peel (CR-EO). CR-EO was obtained by hydrodistillation in a Clevenger-type apparatus and its chemical composition was analyzed by GC-MS and GC-FID. Limonene (85.7%), ɣ-terpinene (6.7%) and myrcene (2.1%) were identified as its major components. CR-EO showed high activity against promastigote forms of Leishmania amazonensis (IC50 = 8.23 µg/mL). CR-EO also exhibited high larvicidal activity against third instar Aedes aegypti larvae at a lethal concentration (LC50 = 58.35 µg/mL) and 100% mortality at 150 µg/mL. This study suggests, for the first time, the potential use of CR-EO against this important mosquito-borne viral disease caused by the genus Aedes.

Resumo Numerosos estudos têm investigado a composição química e as atividades biológicas de óleos essenciais extraídos de cascas dos frutos, folhas e flores de diferentes espécies de Citrus. Este trabalho tem como objetivo investigar a composição química e as atividades larvicida e leishmanicida in vitro do óleo essencial das cascas dos frutos de Citrus reticulata (CR-EO). CR-EO foi obtido pela técnica de extração em aparelho Clevenger e sua composição química foi determinada por CG-EM e CG-DIC. Limoneno (85,7%), ɣ-terpineno (6,7%) and mirceno (2,1%) foram identificados como os constituintes majoritários. CR-EO mostrou alta atividade contra as formas promastigota de Leishmania amazonensis (CI50 = 8,23 µg/mL). CR-EO também exibiu alta atividade larvicida contra as larvas do terceiro estágio do Aedes aegypti com concentração letal (CL50 = 58,35 µg/mL) e mortalidade de 100% em 150 µg/mL. Este estudo sugere, pela primeira vez, o uso potencial de CR-EO contra esta importante doença viral transmitida por mosquitos do gênero Aedes.

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.

DC-SIGN receptor is expressed by cells from cutaneous leishmaniasis lesions and differentially binds to Leishmania (Viannia) braziliensis and L. (Leishmania) amazonensis promastigotes

BACKGROUND Dendritic cells (DCs) specific intercellular adhesion molecule (ICAM)-3-grabbing non integrin receptor (DC-SIGN) binds to subgenera Leishmania promastigotes mediating its interaction with DC and neutrophils, potentially influencing the infection outcome. OBJECTIVES In this work, we investigated whether DC-SIGN receptor is expressed in cells from cutaneous leishmaniasis (CL) lesions as well as the in vitro binding pattern of Leishmania (Viannia) braziliensis (Lb) and L. (L.) amazonensis (La) promastigotes. METHODS DC-SIGN receptor was labeled by immunohistochemistry in cryopreserved CL tissue fragments. In vitro binding assay with CFSE-labeled Lb or La promastigotes and RAJI-transfecting cells expressing DC-SIGN (DC-SIGNPOS) or mock-transfected (DC-SIGNNEG) were monitored by flow cytometry at 2 h, 24 h and 48 h in co-culture. RESULTS In CL lesion infiltrate, DC-SIGNPOS cells were present in the dermis and near the epidermis. Both Lb and La bind to DC-SIGNPOS cells, while binding to DC-SIGNNEG was low. La showed precocious and higher affinity to DC-SIGNhi population than to DC-SIGNlow, while Lb binding was similar in these populations. CONCLUSION Our results demonstrate that DC-SIGN receptor is present in L. braziliensis CL lesions and interact with Lb promastigotes. Moreover, the differences in the binding pattern to Lb and La suggest DC-SIGN can influence in a difference way the intake of the parasites at the first hours after Leishmania infection. These results raise the hypothesis that DC-SIGN receptor could participate in the immunopathogenesis of American tegumentary leishmaniasis accounting for the differences in the outcome of the Leishmania spp. infection.

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.

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.

Desenvolvimento e avaliação de uma proteína quimérica recombinante para o diagnóstico e prognóstico das leishmanioses tegumentar e visceral / Development and evaluation of a recombinant chimeric protein for the diagnosis and prognosis of tegumentary and visceral leishmaniasis

As leishmanioses são doenças tropicais negligenciadas com alta endemicidade e que afetam milhares de pessoas no mundo. Sua infecção é causada por parasitos protozoários do gênero Leishmania. A diversidade biológica entre as espécies é quem permite determinar as manifestações clínicas, sendo elas na forma de leishmaniose visceral (LV) ou leishmaniose tegumentar (LT). Dentre estas manifestações, a LV é considerada a mais grave, devido sua alta letalidade e grande emergência em indivíduos com a infecção provocada pelo vírus da imunodeficiência humana (HIV). Atualmente, as medidas de controle e prevenção adotadas pela Organização Mundial da Saúde (OMS), baseiam-se em uma combinação de estratégias de intervenção contra a infecção, uma vez que o diagnóstico eficaz e precoce é indispensável para que se possa intervir com o tratamento adequado, diminuindo índices de mortalidade e a evolução de complicações clínicas. Entretanto, os testes sorológicos utilizados apresentam sensibilidade e especificidade prejudicadas em pacientes com leishmanioses e/ou coinfectados LV/HIV, devido a baixos ní-veis de anticorpos antileishmanial ou pela presença de doenças que causem reação cruzada, levando a resultados falso-positivos. A sensibilidade torna-se também variável em pacientes tratados, uma vez que a sorologia pode manter-se positiva por meses ou anos após o fim do tratamento e cura da doença. Buscando resolver tal problemática, a identificação de novos antígenos, por meio de análises de bioinformática associadas à imunoproteômica, tem permitido a detecção de novas proteínas com potencial aplicação diagnóstica. Em estudos anteriores, as proteínas hipotéticas LiHyT, LiHyD, LiHyV e LiHyP foram encontradas em espécies de Leishmania spp, e avaliadas em suas versões recombinantes por meio de ensaios de ELISA, obtendo resultados satisfatórios para a detecção da LV humana e canina. Com base nessas informações, o presente trabalho teve como objetivo desenvolver uma proteína quimera recombinante base-ada na predição de epítopos lineares específicos de células B das quatro proteínas antigênicas de L. infantum citadas e avaliar o potencial diagnóstico, assim como dos peptídeos individuais que a constituíram, frente à leishmaniose humana, bem como com a coinfecção com HIV, além de testar os antígenos como marcadores prognóstico após o tratamento da LV e LT. As sequências de aminoácidos das proteínas foram avaliadas e oito epítopos de células B foram preditos e utilizados na construção de uma nova proteína quimérica. A proteína foi expressa, purificada e avaliada como antígeno recombinante em ELISA para o diagnóstico de LV, LT, coinfecção LV/HIV e prognóstico em amostras de pacientes tratados de LV e LT. Os epítopos de células B usados na construção da quimera foram sintetizados e também testados em ELISA frente às mesmas amostras, assim como um extrato antigênico solúvel de Leishmania braziliensis (SLA). Os resultados mostraram que a proteína quimera apresentou sensibilidade e especificidade de 100% para diagnosticar a LV, LT e LV/HIV, enquanto os peptídeos sintéticos apresentaram sensibilidade variando entre eles de 9,1% a 90,9% para amostras de LT e 76,8% a 99,2% para amostras de LV e LV/HIV, já os valores de especificidade atingiram 98,3% a 99,1% para LT e 67,1% a 95,7% para LV e LV/HIV. O SLA apresentou sensibilidade e especificidade de 18,2% e 98,3% para LT, e 56,8% a 69,5% para amostras de LV e LV/HIV, respectivamente. Uma avaliação prognóstica preliminar mostrou ainda que os anticorpos anti-quimera diminuíram em níveis significativos, quando comparada a reatividade sorológica antes e seis meses após o tratamento, sugerindo um possível papel prognóstico da quimera para as leishmanioses. O presente estudo, mostrou-se eficaz na construção e avaliação de novos candidatos, que demonstram ter um bom desempenho na detecção diagnóstica e prognóstica para as leishmanioses e dos casos de coinfecção LV/HIV.

Leishmaniasis are neglected tropical diseases with high endemicity that affect thousands of people in the world. Infection is caused by protozoan parasites of the genus Leishmania. The biological diversity between species is what allows determining the clinical manifestations, either in the form of visceral leishmaniasis (VL) or tegumentary leishmaniasis (TL). Among these clinical manifestations, VL is considered the most serious, due to its high lethality and great emergence in individuals with infection caused by the human immunodeficiency virus (HIV). Currently, the control and prevention measures adopted by the World Health Organiza-tion (WHO) are based on a combination of intervention strategies against the infection, since an effective and early diagnosis is essential to intervene with the appropriate treatment, decrea-sing mortality rates and evolution of clinical complications. However, the serological tests used show impaired sensitivity and specificity in patients with leishmaniasis and/or coinfected with VL/HIV, due to low levels of anti-leishmanial antibodies or the presence of diseases that cause cross-reaction, leading to false-positive results. The sensitivity also becomes variable in treated patients, since the serology can remain positive for months or years after the end of the trea-tment and cure of the disease. Seeking to solve this problem, the identification of new antigens, through bioinformatic analysis associated with immunoproteomic, has allowed the detection of new proteins with potential diagnostic application. In previous studies, the hypothetical proteins LiHyT, LiHyD, LiHyV and LiHyP were found in species of Leishmania spp, and evaluated in their recombinant versions through ELISA assays, and satisfactory results were obtained for the detection of human and canine VL. Based on this information, the present work aimed to develop a recombinant chimera protein through on the prediction of specific linear epitopes of B cells derived from these four antigenic proteins of L. infantum and to evaluate its diagnostic potential, as well as the individual peptides that constitute it, against human leishmaniasis, as well as co-infection with HIV, in addition to testing them as possible prognostic markers of patients after VL and TL treatment. The amino acid sequences of the proteins were evaluated and eight B cell epitopes were predicted and used in the construction of a new chimeric protein. The protein was expressed, purified and evaluated as a recombinant antigen in ELISA for the diagnosis of VL, TL, VL/HIV co-infection and prognosis in samples from patients treated for VL and TL. The B cell epitopes used in the construction of the chimera were synthesized and also tested in ELISA against the same samples, as well as a soluble Leishmania braziliensis antigenic extract (SLA). The results showed that the chimera protein apresented sensitivity and specificity of 100% for diagnosing VL, TL and VL/HIV, while the synthetic peptides showed sensitivity ranging from 9.1% to 90.9% for TL samples and 76.8 % to 99.2% for VL and VL/HIV samples, while the specificity values reached from 98.3% to 99.1% for TL and 67.1% to 95.7% for VL and VL/HIV. The SLA showed sensitivity and specificity of 18.2% and 98.3% for TL, and 56.8% to 69.5% for VL and VL/HIV samples, respectively. A preliminary prog-nostic evaluation also showed that anti-chimera antibodies significantly decreased when com-pared to serological reactivity before and six months after treatment, suggesting a possible prognostic role of the antigen for leishmaniasis. The present study proved to be effective in the construction and evaluation of new candidates, who demonstrate good performance in diagnos-tic and prognostic detection for leishmaniasis and VL/HIV co-infection.

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.

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.

Chemical composition, in vitro larvicidal and antileishmanial activities of the essential oil from Citrus reticulata Blanco fruit peel / Composição química, atividades larvicida e leishmanicida in vitro do óleo essencial da casca do fruto de Citrus reticulata Blanco

Numerous studies have investigated the chemical composition and biological activities of essential oils from different Citrus species fruit peel, leaves and flowers. This paper aims to investigate the chemical composition, larvicidal and antileishmanial activities of essential oil from Citrus reticulata fruit peel (CR-EO). CR-EO was obtained by hydrodistillation in a Clevenger-type apparatus and its chemical composition was analyzed by GC-MS and GC-FID. Limonene (85.7%), ɣ-terpinene (6.7%) and myrcene (2.1%) were identified as its major components. CR-EO showed high activity against promastigote forms of Leishmania amazonensis (IC50 = 8.23 µg/mL). CR-EO also exhibited high larvicidal activity against third instar Aedes aegypti larvae at a lethal concentration (LC50 = 58.35 µg/mL) and 100% mortality at 150 µg/mL. This study suggests, for the first time, the potential use of CR-EO against this important mosquito-borne viral disease caused by the genus Aedes.

Numerosos estudos têm investigado a composição química e as atividades biológicas de óleos essenciais extraídos de cascas dos frutos, folhas e flores de diferentes espécies de Citrus. Este trabalho tem como objetivo investigar a composição química e as atividades larvicida e leishmanicida in vitro do óleo essencial das cascas dos frutos de Citrus reticulata (CR-EO). CR-EO foi obtido pela técnica de extração em aparelho Clevenger e sua composição química foi determinada por CG-EM e CG-DIC. Limoneno (85,7%), ɣ-terpineno (6,7%) and mirceno (2,1%) foram identificados como os constituintes majoritários. CR-EO mostrou alta atividade contra as formas promastigota de Leishmania amazonensis (CI50 = 8,23 µg/mL). CR-EO também exibiu alta atividade larvicida contra as larvas do terceiro estágio do Aedes aegypti com concentração letal (CL50 = 58,35 µg/mL) e mortalidade de 100% em 150 µg/mL. Este estudo sugere, pela primeira vez, o uso potencial de CR-EO contra esta importante doença viral transmitida por mosquitos do gênero Aedes.

Prevalence of cutaneous leishmaniasis in the largest populated city Karachi, Pakistan / Prevalência de leishmaniose cutânea na maior cidade populosa de Karachi, Paquistão

The study was undertaken from September 2018 to April 2019 to determine the prevalence of cutaneous leishmaniasis in human beings living in six districts of Karachi. Suspected persons were screened for the disease and positive cases were identified on the basis of skin lesions and blood samples. Samples were observed by mounting their smear. A total of 207 subjects of different ages and sex groups were investigated, however, only 192 (92%) of the suspected cases were found to have the disease 64% of cases were male which were significantly high (p<0.05), than female 36%. The lesion was more frequently detected among the youth ages of 21-30 years (31%) as compared to other groups. In both sexes, legs were found to be more infected (25% male + 20% female) followed by arms (20% male + 0% female) and face (15% male +11% female). The mixed body parts had shown the lowest infections such as (4% in males + 5%) in females. In conclusion, the highest and lowest leishmaniasis infections were observed in District West (23% male + 9% female) followed by District East (15% male + 7% female), District Malir (11% male+ 4% female), District Central (7% male + 5% female), District Korangi (4% male + 7% female) and District South (4% male + 4% female) respectively.

O estudo foi realizado de setembro de 2018 a abril de 2019 para determinar a prevalência de leishmaniose tegumentar em seres humanos que vivem em seis distritos de Karachi. Pessoas suspeitas foram rastreadas para a doença e os casos positivos foram identificados com base em lesões de pele e amostras de sangue. As amostras foram observadas montando seu esfregaço. Um total de 207 indivíduos de diferentes idades e grupos sexuais foi investigado, no entanto apenas 192 (92%) dos casos suspeitos foram encontrados para ter a doença; 64% dos casos eram do sexo masculino, que foram significativamente elevados (p < 0,05), e do sexo feminino 36%. A lesão foi detectada com maior frequência entre os jovens de 21 a 30 anos (31%) em comparação com os outros grupos. Em ambos os sexos, as pernas estavam mais infectadas (25% homens + 20% mulheres), seguidas pelos braços (20% homens + 0% mulheres) e rosto (15% homens + 11% mulheres). As partes mistas do corpo mostraram as infecções mais baixas (4% homens + 5% mulheres). Em conclusão, as infecções de leishmaniose mais altas e mais baixas foram observadas no Distrito Oeste (23% homens + 9% mulheres) seguido pelo Distrito Leste (15% homens + 7% mulheres), Distrito Malir (11% homens + 4% mulheres), Distrito Central (7% homens + 5% mulheres), Distrito Korangi (4% homens + 7% mulheres) e Distrito Sul (4% homens + 4% mulheres), respectivamente.