RESUMO
Pesticides pose significant risks to both human health, such as cancer, neurological disorders, and endocrine disruption, and ecosystems, through the destruction of beneficial insects, contamination of soil and water, and impact on non-target species. In the face of escalating pesticide pollution, there is an urgent need for multifaceted approaches to address the issue. Bioremediation emerges as a potent tool in the environmental pollution mitigation arsenal. Ideally aiming for the complete decomposition of pesticides into harmless molecules, bioremediation encompasses diverse approaches - from bioabsorption, bioadsorption, and biotransformation using enzymes and nanoenzymes to comprehensive degradation facilitated by microorganisms such as bacteria, fungi, macro- and microalgae, or phytoremediation. Exploring nature's biodiversity offers a promising avenue to find solutions to this pressing human-induced problem. The acceleration of biodegradation necessitates identifying and developing efficient organisms, achieved through bioprospection and targeted modifications. Specific strategies to enhance process efficiency and throughput include optimizing biomass production, strategic inoculation in diverse environments, and employing bioreactor systems for processing heavily contaminated waters or soils. This comprehensive review presents various bioremediation approaches, emphasizing the importance of microorganisms' exploration and new technologies development, including current innovations and patents to effectively combat pesticide pollution. Furthermore, challenges regarding the effective implementation of these technologies are also addressed.
RESUMO
Neglected tropical diseases are those caused by infectious agents or parasites and are considered endemic in low-income populations. These diseases also have unacceptable indicators and low investment in research, drug production, and control. Tropical diseases such as leishmaniasis are some of the main causes of morbidity and mortality around the globe. Electrochemical immunosensors are promising tools for diagnostics against these diseases. One such benefit is the possibility of assisting diagnosis in isolated regions, where laboratory infrastructure is lacking. In this work, different peptides were investigated to detect antibodies against Leishmania in human and canine serum samples. The peptides evaluated (395-KKG and 395-G) have the same recognition site but differ on their solid-binding domains, which ensure affinity to spontaneously bind to either graphene oxide (GO) or graphene quantum dots (GQD). Cyclic voltammetry and differential pulse voltammetry were employed to investigate the electrochemical behavior of each assembly step and the role of each solid-binding domain coupled to its anchoring material. The graphene affinity peptide (395-G) showed better reproducibility and selectivity when coupled to GQD. Under the optimized set of experimental conditions, negative and positive human serum samples responses were distinguished based on a cut-off value of 82.5% at a 95% confidence level. The immunosensor showed selective behavior to antibodies against Mycobacterium leprae and Mycobacterium tuberculosis, which are similar antibodies and potentially sources of false positive tests. Therefore, the use of the graphene affinity peptide as a recognition site achieved outstanding performance for the detection of Leishmania antibodies.
Assuntos
Técnicas Biossensoriais , Grafite , Leishmaniose , Animais , Cães , Humanos , Carbono/química , Grafite/química , Reprodutibilidade dos Testes , Imunoensaio , Peptídeos , Anticorpos , Leishmaniose/diagnósticoRESUMO
The recent geographic spread of Leishmania infantum along the borders of Argentina, Brazil and Paraguay has been highlighted. In our previous study, Lutzomyia longipalpis was found in 55 of 123 patches surveyed, and in some patches, sandflies were found at higher densities, forming hotspots. Based on the One Health approach, we investigated the seasonality of the vector, the presence of parasite DNA, and the environmental factors that contribute to vector and parasite dispersal in these previously described hotspots in Foz do Iguaçu, Brazil. Entomological surveys were conducted monthly for one year. Fourteen hotspots peridomicile and six intradomicile were sampled. PCR was used to assess the prevalence of Leishmania DNA in sandflies. Zero-inflated negative binomial regression was used to determine the association of micro- and mesoscale environmental variables with the occurrence and abundance of the three most abundant sandfly species sampled. A total of 3543 species were captured, with Lutzomyia longipalpis being the predominant species (71.78%) of the 13 species found. Evandromyia edwardsi, Expapillata firmatoi, Micropygomyia ferreirana and Pintomyia christenseni were reported for the first time in the region. NDVI, distance to water, precipitation, west-to-east wind, wind speed, maximum and minimum relative humidity, and sex were significant variables associated with vector presence/abundance in the environment. Vector presence/abundance in the peridomicile was associated with precipitation, altitude, maximum temperature, minimum and maximum relative humidity, west-to-east wind, wind speed, and sex. Leishmania DNA was detected in an average of 21% of Lu. longipalpis throughout the year. Vector abundance is concentrated in urban and peri-urban areas, with some specimens present in different parts of the city and some sites with high vector abundance. This distribution suggests that the risk of actual contact between humans and parasite vectors in urban areas during the epidemic period is associated with patches of peri-urban vegetation and then extends into urban areas.
RESUMO
Electrochemical immunosensors are excellent alternatives to prepare portable platforms used for rapid and inexpensive diagnostic of infectious diseases such as the recently emerged COVID-19. Incorporating synthetic peptides as selective recognition layers combined with nanomaterials such as gold nanoparticles (AuNPs) can significantly enhance the analytical performance of immunosensors. In the present study, an electrochemical immunosensor based on solid-binding peptide was built and evaluated towards SARS-CoV-2 Anti-S antibodies detection. The peptide used as recognition site has two important portions: one based on the viral receptor binding domain (RBD), capable of recognizing antibodies of the spike protein (Anti-S), and another suitable for interacting with gold nanoparticles. Gold-binding peptide (Pept/AuNP) dispersion was used directly to modify a screen-printed carbon electrode (SPE). The voltammetric behavior of the [Fe(CN)6]3-/4- probe after every construction and detection step was recorded using cyclic voltammetry by assessing the stability of the Pept/AuNP as a recognition layer onto the electrode surface. Differential pulse voltammetry was used as a detection technique, and a linear working range from 75 ng mL-1 to 15 µg mL-1 was established, with 1.059 µA dec-1 of sensitivity and R2 = 0.984. The response selectivity against SARS-CoV-2 Anti-S antibodies was investigated in presence of concomitant species. The immunosensor was used to detect SARS-CoV-2 Anti-spike protein (Anti-S) antibodies in human serum samples, successfully differentiating between negative and positive responses of samples at a 95% confidence level. Therefore, the gold-binding peptide is a promising tool to be applied as a selective layer for antibody detection.
Assuntos
Técnicas Biossensoriais , COVID-19 , Nanopartículas Metálicas , Humanos , Ouro/química , SARS-CoV-2 , Técnicas Biossensoriais/métodos , Nanopartículas Metálicas/química , Imunoensaio/métodos , Anticorpos Antivirais , Peptídeos , Técnicas Eletroquímicas/métodosRESUMO
Soybean hulls are lignocellulosic residuesgeneratedinthe industrial processing of soybean, representing about 5 % of the mass of the whole bean. This by-product isan importantsource of polymers suchas cellulose(34 %) and hemicellulose (11 %),which could bevalorizedvia biotechnology to improvethe economic returnof the oilseed chain. In the present work,soybean hulls were evaluated as a carbon sourcefor biolipid productionbyLipomycesstarkeyi LPB 53. Initially the hulls were treated physicochemically and enzymatically to obtain fermentable sugars. Subsequently, biomass growth was evaluated using different nitrogen sources andthe lipid production was optimized, reaching a maximum cell biomass concentration of 26.5 g/L with 42.5 % of lipids. Around 65 % of the xylose content was consumed.The obtained oil wasmajorlycomposed of oleic, palmitic, palmitoleic, linoleic and stearic fatty acids in a proportion of 54 %, 32 %, 4 %, 3 % and 2 %, respectively.
Assuntos
Lipídeos , Lipomyces , Glycine max , FermentaçãoRESUMO
The development of immunosensors to detect antibodies or antigens has stood out in the face of traditional methods for diagnosing emerging diseases such as the one caused by the SARS-CoV-2 virus. The present study reports the construction of a simplified electrochemical immunosensor using a graphene-binding peptide applied as a recognition site to detect SARS-CoV-2 antibodies. A screen-printed electrode was used for sensor preparation by adding a solution of peptide and reduced graphene oxide (rGO). The peptide-rGO suspension was characterized by scanning electron microscopy (SEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). The electrochemical characterization (electrochemical impedance spectroscopy-EIS, cyclic voltammetry-CV and differential pulse voltammetry-DPV) was performed on the modified electrode. The immunosensor response is based on the decrease in the faradaic signal of an electrochemical probe resulting from immunocomplex formation. Using the best set of experimental conditions, the analytic curve obtained showed a good linear regression (r2 = 0.913) and a limit of detection (LOD) of 0.77 µg mL-1 for antibody detection. The CV and EIS results proved the efficiency of device assembly. The high selectivity of the platform, which can be attributed to the peptide, was demonstrated by the decrease in the current percentage for samples with antibody against the SARS-CoV-2 S protein and the increase in the other antibodies tested. Additionally, the DPV measurements showed a clearly distinguishable response in assays against human serum samples, with sera with a response above 95% being considered negative, whereas responses below this value were considered positive. The diagnostic platform developed with specific peptides is promising and has the potential for application in the diagnosis of other infections that lead to high antibody titers.
Assuntos
Técnicas Biossensoriais , COVID-19 , Grafite , Humanos , Grafite/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , SARS-CoV-2 , Espectroscopia de Infravermelho com Transformada de Fourier , Imunoensaio , COVID-19/diagnóstico , Eletrodos , Limite de Detecção , PeptídeosRESUMO
Immunoassays are practical and cost-effective approaches suitable for large-scale tuberculosis (TB) screening. This study identified new peptide mimotopes of Mycobacterium tuberculosis and applied them in the serodiagnosis of TB. Thereby, linear (X15, X8CX8) and constrained (LX-4 and LX-8) phage display peptide libraries were screened with purified Immunoglobulin G antibodies from TB-positive patients, and eight mimotopes were selected. The mimotope peptides were screened using the SPOT-synthesis technique followed by immunoblotting. Peptides P.Mt.PD.4 and P.Mt.PD.7 demonstrated the highest binding affinity and were chemically synthesized and used as antigens for enzyme-linked immunosorbent assay (ELISA) assays. Experimental designs were used to optimize the assays and to assess each variable's influence. Peptide P.Mt.PD.7 was differentiated between positive and negative samples and achieved 100% sensitivity and specificity when tested on a 100-sera panel. Therefore, the selected peptide was applied to the ELISA assay as a screening method for diagnosing TB represents a potential tool for helping to combat the disease.
Assuntos
Bacteriófagos , Mycobacterium tuberculosis , Tuberculose , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Biblioteca de Peptídeos , Peptídeos , Projetos de Pesquisa , Tuberculose/diagnósticoRESUMO
Traditionally, lipid-producing microorganisms have been obtained via conventional bioprospecting based on isolation and screening techniques, demanding time and effort. Thus, high-throughput sequencing combined with conventional microbiological approaches has emerged as an advanced and rapid strategy for recovering novel oleaginous microorganisms from target environments. This review highlights recent developments in lipid-producing microorganism bioprospecting, following (i) from traditional cultivation techniques to state-of-the-art metagenomics approaches; (ii) related topics on workflow, next-generation sequencing platforms, and knowledge bioinformatics; and (iii) biotechnological potential of the production of docosahexaenoic acid (DHA) by Aurantiochytrium limacinum, arachidonic acid (ARA) by Mortierella alpina and biodiesel by Rhodosporidium toruloides. These three species have been shown to be highly promising and studied in research articles, patents and commercialized products. Trends, innovations and future perspectives of these microorganisms are also addressed. Thus, these microbial lipids allow the development of food, feed and biofuels as alternative solutions to animal and vegetable oils.
Assuntos
Bioprospecção , Metagenômica , Animais , Ácido Araquidônico , Biocombustíveis , MetagenomaRESUMO
ABSTRACT Lutzomyia intermedia (Diptera: Psychodidae) features as one of the main vectors that are involved in the transmission of American cutaneous leishmaniasis (ACL) in the Neotropical region. However, genetic studies involving this taxon are still incipient and important for understanding the level of variability of different populations, their role, and implications as vectors. The aim of this study was to determine the level of genetic diversity of L. intermedia present in the Ribeira River Valley, an area of ACL transmission in the state of Paraná, Brazil, through the Random amplified polymorphic DNA (RAPD). Two municipalities were chosen to collect sand flies: Cerro Azul (new transmission area of the ACL) and Adrianópolis (endemic area of the ACL). The insects were captured in the house, in the peridomicile and in the wild (forest). Two of the used markers made it possible to estimate the polymorphism of the studied populations, resulting in 40 genotypes, most of them from peridomicile. The dendrogram generated by the analysis with the primer A10 showed different degrees of similarity, suggesting that there may be gene flow in the studied populations. The Principal Coordinate Analysis (PCO) with the A2 primer, was useful in grouping L. intermedia according to its ecological and geographical origin. There was no distinction between the lineages composing the L. intermedia complex. The results of this study, with the record of great genotypic diversity in L. intermedia, may contribute to explain the maintenance of the life cycle of Leishmania braziliensis (Kinetoplastida: Trypanosomatidae) in the region.
RESUMEN Lutzomyia intermedia (Diptera: Psychodidae) es uno de los principales vectores que participan en la transmisión de leishmaniasis cutánea americana (LCA) en la región Neotropical. A pesar de que aún los estudios genéticos que involucran a este taxón son incipientes, tienen una gran importancia para comprender el nivel de variabilidad de las diferentes poblaciones y sus implicaciones en su papel vectorial. El objetivo de este estudio fue determinar el nivel de diversidad genética de L. intermedia presente en el Valle del Río Ribeira, área de transmisión de LCA en el estado de Paraná, Brasil, mediante RAPD (ADN polimórfico amplificado aleatoriamente). Los flebótomos fueron recolectados en los municipios Cerro Azul (nueva área de transmisión de LCA) y Adrianópolis (área endémica de LCA), donde fueron capturados en ambientes residenciales, en el peridomicilio y en el bosque. Dos de los marcadores utilizados permitieron estimar el polimorfismo en las poblaciones estudiadas con la obtención de 40 genotipos, la mayoría de ellos en el peridomicilio. El dendrograma generado por el análisis con el cebador A10 mostró diferentes grados de similitud, lo que sugiere que puede haber flujo gènico en las poblaciones. El Análisis de Coordenadas Principales (PCO) con el cebador A2 fue útil para agrupar L. intermedia según su origen ecológico y geográfico. No hubo distinción entre los linajes que componen el complejo L. intermedia. Los resultados de este estudio, con el registro de gran diversidad genotipica en L. intermedia, pueden contribuir a explicar el mantenimiento del ciclo biológico de Leishmania braziliensis (Kinetoplastida: Trypanosomatidae) en la región.
RESUMO
We provide the raw and processed data produced during the genome sequencing of isolates from six species of parasites from the sub-family Leishmaniinae: Leishmania martiniquensis (Thailand), Leishmania orientalis (Thailand), Leishmania enriettii (Brazil), Leishmania sp. Ghana, Leishmania sp. Namibia and Porcisia hertigi (Panama). De novo assembly was performed using Nanopore long reads to construct chromosome backbone scaffolds. We then corrected erroneous base calling by mapping short Illumina paired-end reads onto the initial assembly. Data has been deposited at NCBI as follows: raw sequencing output in the Sequence Read Archive, finished genomes in GenBank, and ancillary data in BioSample and BioProject. Derived data such as quality scoring, SAM files, genome annotations and repeat sequence lists have been deposited in Lancaster University's electronic data archive with DOIs provided for each item. Our coding workflow has been deposited in GitHub and Zenodo repositories. This data constitutes a resource for the comparative genomics of parasites and for further applications in general and clinical parasitology.
Assuntos
Genoma de Protozoário , Leishmania/classificação , Filogenia , Genômica , Anotação de Sequência Molecular , Sequências Repetitivas de Ácido NucleicoRESUMO
The generation of agroindustrial byproducts is rising fast worldwide. The slaughter of animals, the production of bioethanol, and the processing of oil palm, cassava, and milk are industrial activities that, in 2019, generated huge amounts of wastewaters, around 2448, 1650, 256, 85, and 0.143 billion liters, respectively. Thus, it is urgent to reduce the environmental impact of these effluents through new integrated processes applying biorefinery and circular economy concepts to produce energy or new products. This review provides the characteristics of some of the most important agro-industrial wastes, including their physicochemical composition, worldwide average production, and possible environmental impacts. In addition, some alternatives for reusing these materials are addressed, focusing mainly on energy savings and the possibilities of generating value-added products. Finally, this review considers recent research and technological innovations and perspectives for the future.
Assuntos
Manihot , Águas Residuárias , Animais , Resíduos Industriais , IndústriasRESUMO
Leishmania (Mundinia) enriettii is a parasitic kinetoplastid first isolated from a guinea pig in Brazil in 1946. We present the complete genome sequence of L. (M.) enriettii, isolate CUR178, strain LV763, sequenced using combined short-read and long-read technologies. This will facilitate a greater understanding of the genome diversity within L. (M.) enriettii.
RESUMO
Knowledge of immunodominant B-cell epitopes is essential to design powerful diagnostic strategies aiming for antibody detection. Outstanding progress in computational prediction has achieved a significant contribution to the biomedical fields, including immunodiagnosis. In silico analysis may have an even more important role when information concerning antigens from etiologic agents of neglected diseases, such as leprosy, is scarce. The aim of this study was to provide mapping of B-cell epitopes from two Mycobacterium leprae-derived antigens (Ag85B and ML2055), confirm their antigenicity, and to assess the ability of in silico immunoinformatics tools to accurately predict them. Linear B-cell epitopes predicted by ABCpred and SVMTrip servers were compared to antigenic regions of synthetic overlapping peptides that exhibited reactivity to antibodies from patients with leprosy. Our in vitro results identified several immunodominant regions that had also been indicated by in silico prediction, providing agreement between experimental and simulated data. After chemical synthesis, we used enzyme-linked immunosorbent assays to determine the effectiveness of the first identified sequence (GTNVPAEFLENFVHG) which had 72 % sensitivity and 78 % specificity (AUC = 0.79) while the second one (PVSSEAQPGDPNAPS) had 72 % sensitivity and 93.8 % specificity (AUC = 0.85). Using dot blotting, an easy-to-read visual test, both peptides could distinguish sera from patients with leprosy from those with tuberculosis and from sera of healthy volunteers. Our findings suggest that these synthetic peptides, with some refinement, may be useful as serological diagnostic antigens for leprosy. In addition, it was displayed that immunoinformatics provides reliable information for mapping potential B-cell epitopes for development of peptide-based diagnostic assays for neglected diseases.
Assuntos
Antígenos de Bactérias/imunologia , Mapeamento de Epitopos/métodos , Epitopos de Linfócito B/imunologia , Hanseníase/diagnóstico , Testes Sorológicos/métodos , Adulto , Anticorpos Antibacterianos/imunologia , Feminino , Humanos , Hanseníase/sangue , Hanseníase/imunologia , Masculino , Pessoa de Meia-Idade , Mycobacterium lepraeRESUMO
We present the LGAAP computational pipeline, which was successfully used to assemble six genomes of the parasite subfamily Leishmaniinae to chromosome-scale completeness from a combination of long- and short-read sequencing data. LGAAP is open source, and we suggest that it may easily be ported for assembly of any genome of comparable size (â¼35 Mb).
RESUMO
Without standardized methods for rapidly detecting in food matrices viable T. cruzi, foodborne outbreaks remain neglected. In this work, a reverse-transcriptase real-time PCR (RT-qPCR) mRNA-based technique was developed for the rapid and specific detection and quantification of viable Trypanosoma cruzi in açai fruits and juice. The method uses specific primer targeting region on the cyt b gene. The maximum recovery rate of T. cruzi from inoculated açai juice was 82.50%. The limit of detection and quantification in açai juice was 10 parasites/mL for RT-qPCR (mRNA-based) and qPCR (DNA-based). The RT-qPCR efficiency was estimated at 97.27% with an R2 of 0.994. The RT-qPCR was shown to be able to discriminate between viable and nonviable cells. This method provides a useful tool for rapid assessment of low concentrations of viable T. cruzi in naturally contaminated food samples, and can be applied industrially as a quality and security method.
Assuntos
Doença de Chagas , Trypanosoma cruzi , Doença de Chagas/epidemiologia , Surtos de Doenças , Inocuidade dos Alimentos , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Trypanosoma cruzi/genéticaRESUMO
Omega-3 produced by marine thraustochytrids has appeared as an alternative to fish oil and an eco-friendly solution to overfishing. Herein, an integrative analysis of metagenetics and high-throughput screening was used for bioprospecting marine thraustochytrids from southern Brazil mangrove and coastal seawater. All sampled environments showed biodiversity and abundance of SAR clade. Environmental samples detected with potential lipid-accumulating labyrinthulomycetes were further processed for direct plating and pollen baiting isolation. Microtiter plate system and fluorescence spectroscopy were combined for high-throughput screening of 319 isolates to accumulate lipids. Twenty isolates were selected for submerged cultivation and lipid characterization. Among them, B36 isolate, identified as Aurantiochytrium sp. by 18s rRNA sequencing, achieved the highest biomass (25.60 g/l CDW) and lipids (17.12 g/l CDW). This lipid content had a high biological value with 44.37% LC-PUFAs and 34.6% DHA, which can be used as a sustainable source in vegan, seafood-free and animal feed diets.
Assuntos
Ácidos Docosa-Hexaenoicos , Estramenópilas , Animais , Bioprospecção , Brasil , Conservação dos Recursos Naturais , Ácidos Graxos , Ácidos Graxos Insaturados , Pesqueiros , Ensaios de Triagem em Larga Escala , Estramenópilas/genéticaRESUMO
Visceral leishmaniosis is one of the most important zoonotic diseases on the planet and dogs are the main reservoir of canine visceral leishmaniosis (CVL) in endemic areas. They play an important role in human infection because in dogs the disease appears long time after infection, and they can move uncontrollably, contributing to disperse the parasite. To take the decision to treat the animals or for euthanasia, in an elimination programme, in order to reduce the parasitic load, it is necessary to diagnose correctly, having more effective tools. Our group has developed a new recombinant antigen-based kinesin-related gene of Leishmania braziliensis (Lbk39), which shows 59% amino acid identity to the L. infantum homologue. The Lbk39 gene was synthesized, inserted into the pLEXSY-sat2 vector and transfected into L. tarentolae cells by electroporation. The recombinant protein was secreted in the culture with a C-terminal histidine marker, purified, generating a product at 337.68 µg mL-1. A total of 152 sera from dog's endemic and non-endemic areas were used, being 78 positives and 75 negatives. The antigen Lbk39 showed 100% sensitivity and 96.1% specificity. We compared this antigen with other antigens such as total extract of the parasite, TRDPP, and our data indicate that Lbk39 has potential application in the diagnosis of CVL through antibody detection.
Assuntos
Doenças do Cão/diagnóstico , Leishmania braziliensis/genética , Leishmaniose Visceral/veterinária , Proteínas de Protozoários/uso terapêutico , Animais , Doenças do Cão/parasitologia , Cães , Leishmania/genética , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/parasitologia , Microrganismos Geneticamente Modificados/genética , Proteínas Recombinantes/uso terapêuticoRESUMO
Abstract The rapid and accurate diagnosis of tuberculosis (TB), especially considering limited resources, is still a challenge. Development of new methodologies and tests are needed to overcome several disadvantages of the available standard tests. We evaluated the diagnostic potential of two antigens specific for Mycobacterium tuberculosis, the CFP10 and ESAT6 recombinant proteins, and developed stable formulations thereof. Sensitivity and specificity of the delayed-type hypersensitivity (DTH) skin testing and the induction of gamma interferon production (IFN-γ) by lymphocytes, as a non-invasive test, were evaluated using the CFP10 and ESAT6 protein formulations. The recombinant proteins produced by our group presented a high DTH response and the ability to differentiate between tuberculosis infection, BCG vaccination, and the contact with non-tuberculous mycobacteria (NTM). The production of IFN-γ by stimulation with individual and combined proteins was detected in a panel of 40 individuals and showed a specificity of 100% and a sensitivity of 90% when the two proteins were used together. Lyophilized formulations were stable under all conditions, while soluble formulations were stable under freezing at -20 ºC and -80 ºC. The proposed formulations containing the ESAT6 and CFP10 recombinant antigens constitute satisfactory tools for TB testing, suitable to be developed and implemented in a large-scale trial.
Assuntos
Tuberculose/diagnóstico , Interferon gama , Mycobacterium tuberculosis/isolamento & purificação , Antígenos/químicaRESUMO
Antigen formulation is the main feature for the success of leishmaniosis diagnosis and vaccination, since the disease is caused by different parasite species that display particularities which determine their pathogenicity and virulence. It is desirable that the antigens are recognized by different antibodies and are immunogenic for almost all Leishmania species. To overcome this problem, we selected six potentially immunogenic peptides derived from Leishmania histones and parasite membrane molecules obtained by phage display or spot synthesis and entrapped in liposome structures. We used these peptides to immunize New Zealand rabbits and determine the immunogenic capacity of the chimeric antigen. The peptides induced the production of antibodies as a humoral immune response against L. braziliensis or L. infantum. Next, to evaluate the innate response to induce cellular activation, macrophages from the peptide mix-immunized rabbits were infected in vitro with L. braziliensis or L. infantum. The peptide mix generated the IFN-γ, IL-12, IL-4 and TGF-ß that led to Th1 and Th2 cellular immune responses. Interestingly, this mix of peptides also induced high expression of iNOS. These results suggest that the mix of peptides derived from histone and parasites membrane molecules was able to mimic parasites proteins and induce cytokines important to CD4+ T cell Th1 and Th2 differentiation and effector molecule to control the parasite infection. Finally, this peptide induced an immune balance that is important to prevent immunopathological disorders, inflammatory reactions, and control the parasite infection.
RESUMO
Abstract The aim of this study was to confirm the emergence of canine visceral leishmaniasis among dogs in Foz do Iguaçu. The disease was diagnosed through the isolation and molecular identification of Leishmania infantum. In the first sample collection stage (2012), three lymph node aspirates and 46 buffy coat samples were obtained mostly from the dogs that were seroreagents for leishmaniasis. In the second sample collection stage (2013), the buffy coat samples were collected from 376 dogs located close to Paraguay, Paraná river, center and peripheral parts of the city. The DNA from the six isolates, four from the first sampling stage (4/49) and two from the second sampling stage (2/376), was subjected to polymerase chain reaction using the K26F/R primers. The isolate was confirmed as L. infantum by sequencing. As none of the dogs had ever left the city, the isolates were confirmed as autochthonous. Further, the study confirmed the emergence of canine visceral leishmaniasis in Paraná through the identification of L. infantum among dogs in Foz do Iguaçu city. Hence, collaborative control measures should be designed and implemented by the public agencies and research institutions of Brazil, Argentina, and Paraguay to control the spread of visceral leishmaniasis.
Resumo O objetivo deste estudo foi confirmar a emergência da leishmaniose visceral canina em Foz do Iguaçu próximo à fronteira com a Argentina e ao Paraguai, por meio do isolamento e identificação molecular de Leishmania infantum. Em um primeiro estágio de coleta de animais (2012), três amostras de aspirados de linfonodos e 46 camadas leucocitárias foram obtidas de cães soropositivos para leishmaniose. Em um segundo estágio de coleta (2013), foram coletadas amostras de camada leucocitária de 376 cães de 20 localidades próximas à fronteira com o Paraguai, rio Paraná, centro e periferia da cidade. Seis isolados foram obtidos, quatro da primeira etapa (4/49) e dois da segunda etapa (2/376); estes isolados foram submetidos à amplificação com iniciadores K26F/R, e a análise de sua sequência confirmou a espécie como L. infantum. A autoctonia dos casos foi confirmada, pois 100% dos cães nunca haviam saído da cidade. O estudo confirma a emergência de leishmaniose visceral canina no Paraná com identificação de L. infantum em cães da cidade de Foz do Iguaçu. Assim, medidas de controle devem ser elaboradas e implementadas por órgãos públicos e instituições de pesquisa do Brasil, Argentina e Paraguai em parceria com o objetivo de controlar a disseminação de zoonoses e os casos humanos de LV.