RESUMO
BACKGROUND: Zoonotic visceral leishmaniasis is caused by the protozoan Leishmania infantum and is highly lethal in humans and dogs if left untreated. The frequency of this parasite and associated histological changes in the pancreas of dogs are poorly studied. Therefore, the objectives of this study were to evaluate the frequency of detection and load of amastigotes in the pancreas of L. infantum-seropositive dogs and to identify the clinical signs and histological changes associated with parasitism of this organ. METHODS: One hundred forty-three dogs from an endemic area in Brazil that tested seropositive for L. infantum were studied. The dogs were clinically examined, killed, and necropsied between 2013 and 2014. One fragment of the pancreas was randomly collected for histopathology and immunohistochemistry, and spleen and bone marrow were collected for culture. RESULTS: Leishmania amastigotes were detected in the pancreas of 22 dogs (15.4%) by immunohistochemistry, all exhibiting L. infantum parasitism in the spleen and/or bone marrow. Poor body condition and cachexia were only associated with infection of the pancreas with Leishmania spp. (p = 0.021) and were found in 40.9% of dogs with pancreatic infection. Anorexia, vomiting, and/or diarrhea were observed in 9.2% of dogs with pancreatitis. The median parasite load in the pancreas was 1.4 infected macrophages/mm2. Pancreatic histological changes and their frequencies were: granulomatous pancreatitis (28.0%), lymphoplasmacytic pancreatitis (23.8%), acinar cell degeneration (6.3%), fibrosis (5.6%), hemorrhage (2.1%), eosinophilic pancreatitis (0.7%), suppurative pancreatitis (0.7%), and necrosis (0.7%). CONCLUSIONS: The present results demonstrate that L. infantum is one of the etiological agents of chronic pancreatitis in dogs; however, the frequency of detection and parasite load are low in this organ. The lack of an association of poor body condition and cachexia with pancreatitis and the low frequency of clinical signs commonly associated with pancreatitis suggest that a significant portion of the organ is not affected by this parasite. On the other hand, the association of poor body condition and cachexia with concomitant infection of the pancreas, spleen, and/or bone marrow with this parasite suggests that these manifestations are the result of a more advanced stage of canine visceral leishmaniasis.
Assuntos
Leishmania infantum/imunologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/veterinária , Pâncreas/patologia , Pâncreas/parasitologia , Carga Parasitária/estatística & dados numéricos , Animais , Doenças do Cão/imunologia , Doenças do Cão/parasitologia , Cães , Feminino , Técnicas Histológicas , Imuno-Histoquímica/métodos , Leishmania infantum/patogenicidade , Leishmaniose Visceral/parasitologia , MasculinoRESUMO
Visceral Leishmaniasis and HIV-AIDS coinfection (VL/HIV) is considered a life-threatening pathology when undiagnosed and untreated, due to the immunosuppression caused by both diseases. Serological tests largely used for the VL diagnosis include the direct agglutination test (DAT), ELISA and immunochromatographic (ICT) assays. For VL diagnosis in HIV infections, different studies have shown that the use of the DAT assay facilitates the VL diagnosis in co-infected patients, since the performance of the most widely used ELISA and ICT tests, based on the recombinant protein rK39, are much less efficient in HIV co-infections. In this scenario, alternative recombinant antigens may help the development of new serological diagnostic methods which may improve the VL diagnosis for the co-infection cases. This work aimed to evaluate the use of the recombinant Lci2 antigen, related to, but antigenically more diverse than rK39, for VL diagnosis in co-infected sera through ELISA assays. A direct comparison between recombinant Lci2 and rK39 was thus carried out. The two proteins were first tested using indirect ELISA with sera from VL afflicted individuals and healthy controls, with similar performances. They were then tested with two different sets of VL/HIV co-infected cases and a significant drop in performance, for one of these groups, was observed for rK39 (32% sensitivity), but not for Lci2 (98% sensitivity). In fact, an almost perfect agreement (Kappa: 0.93) between the Lci2 ELISA and DAT was observed for the coinfected VL/HIV patients. Lci2 then has the potential to be used as a new tool for the VL diagnosis of VL/HIV co-infections.
Assuntos
Anticorpos Antiprotozoários/isolamento & purificação , Infecções por HIV/genética , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/diagnóstico , Proteínas Recombinantes/isolamento & purificação , Testes de Aglutinação , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Coinfecção/diagnóstico , Coinfecção/genética , Coinfecção/parasitologia , Ensaio de Imunoadsorção Enzimática , HIV/patogenicidade , Infecções por HIV/complicações , Infecções por HIV/parasitologia , Infecções por HIV/virologia , Humanos , Leishmania infantum/genética , Leishmania infantum/patogenicidade , Leishmaniose Visceral/genética , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/virologia , Proteínas de Protozoários/imunologia , Proteínas Recombinantes/genéticaRESUMO
Leishmania infantum causes visceral leishmaniasis, a deadly vector-borne disease introduced to the Americas during the colonial era. This non-native trypanosomatid parasite has since established widespread transmission cycles using alternative vectors, and human infection has become a significant concern to public health, especially in Brazil. A multi-kilobase deletion was recently detected in Brazilian L. infantum genomes and is suggested to reduce susceptibility to the anti-leishmanial drug miltefosine. We show that deletion-carrying strains occur in at least 15 Brazilian states and describe diversity patterns suggesting that these derive from common ancestral mutants rather than from recurrent independent mutation events. We also show that the deleted locus and associated enzymatic activity is restored by hybridization with non-deletion type strains. Genetic exchange appears common in areas of secondary contact but also among closely related parasites. We examine demographic and ecological scenarios underlying this complex L. infantum population structure and discuss implications for disease control.
Assuntos
DNA de Protozoário/genética , Evolução Molecular , Genes de Protozoários , Genoma de Protozoário , Leishmania infantum/genética , Leishmaniose Visceral/parasitologia , Brasil/epidemiologia , Deleção de Genes , Leishmania infantum/patogenicidade , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Epidemiologia Molecular , Filogenia , Deleção de Sequência , Sequenciamento Completo do GenomaRESUMO
Owing to the importance and clinical diversity of Leishmania infantum, studying its virulence factors is promising for understanding the relationship between parasites and hosts. In the present study, differentially abundant proteins from strains with different degrees of virulence in promastigote and amastigote forms were compared using two quantitative proteomics techniques, differential gel electrophoresis and isobaric mass tag labeling, followed by identification by mass spectrometry. A total of 142 proteins were identified: 96 upregulated and 46 downregulated proteins in the most virulent strain compared to less virulent. The interaction between the proteins identified in each evolutionary form was predicted. The results showed that in the amastigote form of the most virulent strain, there was a large group of proteins related to glycolysis, heat shock, and ribosomal proteins, whereas in the promastigote form, the group consisted of stress response, heat shock, and ribosomal proteins. In addition, biological processes related to metabolic pathways, ribosomes, and oxidative phosphorylation were enriched in the most virulent strain (BH400). Finally, we noted several proteins previously found to play important roles in L. infantum infection, which showed increased abundance in the virulent strain, such as ribosomal proteins, HSP70, enolase, fructose 1,6-biphosphate aldolase, peroxidoxin, and tryparedoxin peroxidase, many of which interact with each other.
Assuntos
Leishmania infantum/metabolismo , Leishmania infantum/patogenicidade , Proteoma/metabolismo , Proteínas de Protozoários/metabolismo , Animais , Leishmania infantum/crescimento & desenvolvimento , Estágios do Ciclo de Vida , Proteômica , Virulência , Fatores de Virulência/metabolismoRESUMO
rIL-10 plays a major role in restricting exaggerated inflammatory and immune responses, thus preventing tissue damage. However, the restriction of inflammatory and immune responses by IL-10 can also favor the development and/or persistence of chronic infections or neoplasms. Dogs that succumb to canine leishmaniasis (CanL) caused by L. infantum develop exhaustion of T lymphocytes and are unable to mount appropriate cellular immune responses to control the infection. These animals fail to mount specific lymphoproliferative responses and produce interferon gamma and TNF-alpha that would activate macrophages and promote destruction of intracellular parasites. Blocking IL-10 signaling may contribute to the treatment of CanL. In order to obtain a tool for this blockage, the present work endeavored to identify the canine casIL-10R1 amino acid sequence, generate a recombinant baculovirus chromosome encoding this molecule, which was expressed in insect cells and subsequently purified to obtain rcasIL-10R1. In addition, rcasIL-10R1 was able to bind to homologous IL-10 and block IL-10 signaling pathway, as well as to promote lymphoproliferation in dogs with leishmaniasis caused by L. infantum.
Assuntos
Interleucina-10/metabolismo , Leishmaniose/tratamento farmacológico , Receptores de Interleucina-10/metabolismo , Animais , Linhagem Celular , Citocinas/metabolismo , Doenças do Cão/genética , Cães , Feminino , Imunidade Celular/imunologia , Imunidade Celular/fisiologia , Interferon gama/genética , Interleucina-10/agonistas , Interleucina-12/genética , Leishmania infantum/imunologia , Leishmania infantum/patogenicidade , Leishmaniose/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Receptores de Interleucina-10/efeitos dos fármacos , Transdução de Sinais , Linfócitos T/imunologia , Fator de Necrose Tumoral alfaRESUMO
Diagnosing Canine Visceral Leishmaniosis is challenging for veterinarians given that its hematological and biochemical abnormalities greatly resemble those of other illnesses of dogs, such as canine ehrlichiosis, which is caused by Ehrlichia canis and is highly prevalent with high pathogenicity. The aim of this study was to determine occurrences of serological positivity for the antigens of Ehrlichia canis and Leishmania infantum and its relationship to globulin concentrations in samples from dogs. Out of 93 samples tested, 12.9% were negative for the antigens of both L. infantum and E. canis; 33.3% were seropositive for both antigens. Discordant results were found from 18.3% that were positive only for L. infantum, while 35.5% were positive only for E. canis. Hyperglobulinemia was observed in 88.2% and the statistical analysis showed that there was a significant relationship between the high levels of globulins and seropositivity for the antigen of E. canis. However, the relationship between positivity for the antigen of L. infantum and hyperglobulinemia, showed that there was no statistically significant relationship between the two laboratory findings. From these results, it can be concluded that concomitant infections occur frequently and that hyperglobulinemia is more closely related to ehrlichiosis than to leishmaniosis, in dogs.(AU)
O diagnóstico da leishmaniose canina é um desafio ao Médico Veterinário visto que anormalidades hematológicas e bioquímicas muito se assemelham à outras enfermidades dos cães, como a erliquiose canina, causada pela Ehrlichia canis, muito prevalente e de alta patogenicidade. O objetivo deste estudo foi determinar a positividade sorológica frente aos antígenos de Ehrlichia canis e Leishmania infantum e a sua relação com as concentrações de globulinas em amostras de cães. Das 93 amostras testadas, 12,9% foram negativas frente aos antígenos de E. canis e L. infantum e 33% foram soropositivas. Resultados discordantes foram encontradas em 18,3% positivas apenas para L. infantum, enquanto que 35,5% reagiram apenas frente a E. canis. Hiperglobulinemia foi observada em 88,2% das amostras e a análise estatística mostrou haver relação significante entre a soropositividade frente aos antígenos de E. canis e a hiperglobulinemia, e em contrapartida, a relação entre esse aumento de globulinas e a positividade para L. infantum foi insignificante. Pelos resultados apresentados, pode-se concluir que as infecções concomitantes são frequentes e que a hiperglobulinemia está mais intimamente relacionada a erliquiose quando comparada à leishmaniose em cães.(AU)
Assuntos
Animais , Cães , Biomarcadores , Soro , Leishmaniose/diagnóstico , Ehrlichiose/diagnóstico , Cães/sangue , Cães/microbiologia , Ehrlichia canis/patogenicidade , Leishmania infantum/patogenicidadeRESUMO
Diagnosing Canine Visceral Leishmaniosis is challenging for veterinarians given that its hematological and biochemical abnormalities greatly resemble those of other illnesses of dogs, such as canine ehrlichiosis, which is caused by Ehrlichia canis and is highly prevalent with high pathogenicity. The aim of this study was to determine occurrences of serological positivity for the antigens of Ehrlichia canis and Leishmania infantum and its relationship to globulin concentrations in samples from dogs. Out of 93 samples tested, 12.9% were negative for the antigens of both L. infantum and E. canis; 33.3% were seropositive for both antigens. Discordant results were found from 18.3% that were positive only for L. infantum, while 35.5% were positive only for E. canis. Hyperglobulinemia was observed in 88.2% and the statistical analysis showed that there was a significant relationship between the high levels of globulins and seropositivity for the antigen of E. canis. However, the relationship between positivity for the antigen of L. infantum and hyperglobulinemia, showed that there was no statistically significant relationship between the two laboratory findings. From these results, it can be concluded that concomitant infections occur frequently and that hyperglobulinemia is more closely related to ehrlichiosis than to leishmaniosis, in dogs.
O diagnóstico da leishmaniose canina é um desafio ao Médico Veterinário visto que anormalidades hematológicas e bioquímicas muito se assemelham à outras enfermidades dos cães, como a erliquiose canina, causada pela Ehrlichia canis, muito prevalente e de alta patogenicidade. O objetivo deste estudo foi determinar a positividade sorológica frente aos antígenos de Ehrlichia canis e Leishmania infantum e a sua relação com as concentrações de globulinas em amostras de cães. Das 93 amostras testadas, 12,9% foram negativas frente aos antígenos de E. canis e L. infantum e 33% foram soropositivas. Resultados discordantes foram encontradas em 18,3% positivas apenas para L. infantum, enquanto que 35,5% reagiram apenas frente a E. canis. Hiperglobulinemia foi observada em 88,2% das amostras e a análise estatística mostrou haver relação significante entre a soropositividade frente aos antígenos de E. canis e a hiperglobulinemia, e em contrapartida, a relação entre esse aumento de globulinas e a positividade para L. infantum foi insignificante. Pelos resultados apresentados, pode-se concluir que as infecções concomitantes são frequentes e que a hiperglobulinemia está mais intimamente relacionada a erliquiose quando comparada à leishmaniose em cães.
Assuntos
Animais , Cães , Biomarcadores , Cães/microbiologia , Cães/sangue , Ehrlichiose/diagnóstico , Leishmaniose/diagnóstico , Soro , Ehrlichia canis/patogenicidade , Leishmania infantum/patogenicidadeRESUMO
We describe the immature stages of Migonemyia migonei, which is the vector of Leishmania (Viannia) braziliensis, the etiological agent of cutaneous leishmaniasis in South America, and a putative vector of Leishmania infantum chagasi. Scanning Electron Microscopy (SEM) was used to refine the description of the structures of the egg, all instar larvae, and the pupa. The eggs have polygonal cells on the egg exochorion, and differences between larval and pupal chaetotaxy have been highlighted. Different sensillary subtypes-trichoidea, basiconica, coelonica and campanoformia-were observed in the larval stages. The results presented herein contribute to the taxonomy of Mg. migonei and may contribute to future studies on the phylogeny of this important vector species.
Assuntos
Dípteros/ultraestrutura , Insetos Vetores/ultraestrutura , Animais , Dípteros/crescimento & desenvolvimento , Dípteros/parasitologia , Feminino , Insetos Vetores/crescimento & desenvolvimento , Insetos Vetores/parasitologia , Larva/ultraestrutura , Leishmania infantum/patogenicidade , Masculino , Microscopia Eletrônica de Varredura , Óvulo/ultraestrutura , Pupa/ultraestruturaRESUMO
Leishmaniasis has been considered as emerging and re-emerging disease, and its increasing global incidence has raised concerns. The great clinical diversity of the disease is mainly determined by the species. In several American countries, tegumentary leishmaniasis (TL) is associated with both Leishmania amazonensis and L. braziliensis, while visceral leishmaniasis (VL) is associated with L. (L.) infantum. The major molecules that determine the most diverse biological variations are proteins. In the present study, through a DIGE approach, we identified differentially abundant proteins among the species mentioned above. We observed a variety of proteins with differential abundance among the studied species; and the biological networks predicted for each species showed that many of these proteins interacted with each other. The prominent proteins included the heat shock proteins (HSPs) and the protein network involved in oxide reduction process in L. amazonensis, the protein network of ribosomes in L. braziliensis, and the proteins involved in energy metabolism in L. infantum. The important proteins, as revealed by the PPI network results, enrichment categories, and exclusive proteins analysis, were arginase, HSPs, and trypanothione reductase in L. amazonensis; enolase, peroxidoxin, and tryparedoxin1 in L. braziliensis; and succinyl-CoA ligase [GDP -forming] beta-chain and transaldolase in L. infantum.
Assuntos
Leishmania braziliensis/patogenicidade , Leishmania infantum/patogenicidade , Leishmania mexicana/patogenicidade , Leishmaniose Cutânea/parasitologia , Proteínas de Protozoários/metabolismo , Biologia Computacional , Humanos , Leishmania braziliensis/metabolismo , Leishmania infantum/metabolismo , Leishmania mexicana/metabolismo , Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas , Proteínas de Protozoários/isolamento & purificaçãoRESUMO
Protozoan parasites of the genus Leishmania are causative agents of leishmaniasis, a wide range of diseases affecting 12 million people worldwide. The species L. infantum and L. amazonensis are etiologic agents of visceral and cutaneous leishmaniasis, respectively. Most proteome analyses of Leishmania have been carried out on whole-cell extracts, but such an approach tends to underrepresent membrane-associated proteins due to their high hydrophobicity and low solubility. Considering the relevance of this category of proteins in virulence, invasiveness and the host-parasite interface, this study applied label-free proteomics to assess the plasma membrane sub-proteome of L. infantum and L. amazonensis. The number of proteins identified in L. infantum and L. amazonensis promastigotes was 1168 and 1455, respectively. After rigorous data processing and mining, 157 proteins were classified as putative plasma membrane-associated proteins, of which 56 proteins were detected in both species, six proteins were detected only in L. infantum and 39 proteins were exclusive to L. amazonensis. The quantitative analysis revealed that two proteins were more abundant in L. infantum, including the glucose transporter 2, and five proteins were more abundant in L. amazonensis. The identified proteins associated with distinct processes and functions. In this regard, proteins of L. infantum were linked to metabolic processes whereas L. amazonensis proteins were involved in signal transduction. Moreover, transmembrane transport was a significant process among the group of proteins detected in both species and members of the superfamily of ABC transporters were highly represented. Interestingly, some proteins of this family were solely detected in L. amazonensis, such as ABCA9. GP63, a well-known virulence factor, was the only GPI-anchored protein identified in the membrane preparations of both species. Finally, we found several proteins with uncharacterized functions, including differentially abundant ones, highlighting a gap in the study of Leishmania proteins. Proteins characterization could provide a better biological understanding of these parasites and deliver new possibilities regarding the discovery of therapeutic targets, drug resistance and vaccine candidates.
Assuntos
Leishmania infantum/química , Leishmania mexicana/química , Proteínas de Membrana/análise , Proteômica/métodos , Proteínas de Protozoários/análise , Animais , Membrana Celular/química , Cromatografia Líquida , Biologia Computacional , Cricetinae , Transportador de Glucose Tipo 2/análise , Interações Hospedeiro-Parasita , Leishmania infantum/metabolismo , Leishmania infantum/patogenicidade , Leishmania infantum/ultraestrutura , Leishmania mexicana/ultraestrutura , Macrófagos Peritoneais/parasitologia , Espectrometria de Massas , Mesocricetus , Metaloendopeptidases/análise , Camundongos , Camundongos Endogâmicos BALB C , Transdução de Sinais , Espectrometria de Massas em Tandem , VirulênciaRESUMO
Leishmania infantum is a trypanosomatid that causes parasitic dermatopathy in dogs. Trypanosoma caninum is another trypanosomatid, which infects the skin of dogs, although cutaneous abnormalities are absent. This study aimed to investigate the occurrence of T. caninum infection and its associated cutaneous and histological changes and compare it with the occurrence of L. infantum infection in dogs. The study included 150 dogs, of which T. caninum infection was identified in 3 (2%) and L. infantum infection in 15 (10%) of them, with no association (p>0.05) of these infections with the breed, gender, age, or cutaneous abnormalities. The cutaneous abnormalities were based on 1 (4.8%) and 12 (57.1%) dogs infected by T. caninum and L. infantum, respectively. The dermatohistopathological abnormalities in the dogs infected with T. caninum included mild perivascular lymphohistioplasmacytic infiltrates in the clinically asymptomatic ones, while in those with dermatological abnormalities, acanthosis, epidermal orthokeratotic hyperkeratosis, melanomacrophages, and co-infection with Microsporum sp. and Trichophyton sp. were observed. InL. infantum infected, the histopathological findings included chronic granulomatous inflammatory infiltrates and structures compatible with amastigotes. Despite the low frequency of T. caninum infection, our findings suggest that this trypanosomatid, unlike L. infantum, does not cause any macroscopic skin abnormalities.(AU)
Leishmania infantum é um tripanosomatídeo que causa dermatopatia parasitária em cães. Trypanosoma caninum é outro tripanosomatídeo, que infecta a pele de cães, embora anormalidades cutâneas sejam ausentes. Este estudo teve como objetivo investigar a ocorrência da infecção por T. caninum e suas alterações cutâneas e histológicas associadas e compará-las com a ocorrência da infecção por L. infantum em cães. O estudo incluiu 150 cães, dos quais a infecção por T. caninum foi identificada em 3 (2%) e a infecção por L. infantum em 15 (10%) deles, sem associação (p>0,05) dessas infecções com a raça, sexo, idade ou anormalidades cutâneas. As alterações cutâneas foram observadas em 1 (4,8%) e 12 (57,1%) cães infectados por T. caninum e L. infantum, respectivamente. As anormalidades dermato-histopatológicas nos cães infectados por T. caninum incluíram infiltrados linfo-histioplasmocitários perivasculares leves nos clinicamente assintomáticos, enquanto naqueles com anormalidades dermatológicas, foram observados acantose, hiperqueratose ortoqueratótica epidermal e melanomacrófagos e co-infecção por Microsporum sp. e Trichophyton sp. Nos cães infectados por L. infantum, os achados histopatológicos incluíram infiltrados inflamatórios granulomatosos crônicos e estruturas compatíveis com amastigotas. A despeito da baixa frequência da infecção por T. caninum, nossos achados sugerem que esse tripanosomatídeo, diferentemente de L. infantum, não causa anormalidades macroscópicas na pele.(AU)
Assuntos
Animais , Cães , Trypanosoma/classificação , Trypanosoma/parasitologia , Trypanosoma/patogenicidade , Leishmania infantum/classificação , Leishmania infantum/parasitologia , Leishmania infantum/patogenicidade , Cães/parasitologiaRESUMO
The main clinical, anatomopathological, and molecular aspects of the infection by Leishmania infantum are described in two cats with multicentric cutaneous, nodular, and ulcerated lesions. The animals were submitted to a clinical examination, followed by serological, molecular and parasitological exams, with culture and isolation of the parasite, and subsequent isoenzymatic characterization. The animals were euthanized and necropsied. Case 1 was an adult, female, mixed-bred stray cat. Case 2 was an adult, male, mixed-bred and domiciled cat. Both were positive for the presence of anti-L. infantum antibodies. In the cytology of the cutaneous nodules and lymph nodes, amastigote forms of Leishmania spp. could be visualized, free and in the interior of the macrophages. In the histopathology, the lesions were characterized by nodular granulomatous and/or ulcerative dermatitis, associated to amastigote forms of Leishmania spp. By means of the polymerase chain reaction, the sequence of the L. infantum kDNA minicircle was amplified. It is concluded that the infection by L. infantum occurs in cats in the State of Paraíba, Northeast region of Brazil and the need to understand the immunological profile of the visceral leishmaniasis in the feline population is highlighted with aimed at the control measures in public health.(AU)
Descrevem-se os principais aspectos clínicos, anatomopatológicos e moleculares da infecção por Leishmania infantum em dois gatos, cuja queixa era de lesões cutâneas multicêntricas, nodulares e ulceradas. Os animais foram submetidos à avaliação clínica, seguida de exames sorológicos, molecular e parasitológico, com cultura e isolamento do parasita e posterior caracterização isoenzimática. Os animais foram eutanasiados e encaminhados para a necropsia. O caso 1 era uma gata adulta, sem raça definida e errante. O caso 2 era um gato adulto, sem raça definida e domiciliado. Ambos foram positivos para a presença de anticorpos anti-L. infantum. Na citologia dos nódulos cutâneos e linfonodos, puderam ser visualizadas formas amastigotas de Leishmania spp. livres e no interior de macrófagos. Na histopatologia, as lesões se caracterizavam por dermatite granulomatosa nodular e/ou ulcerativa, associadas a formas amastigotas de Leishmania spp. Por meio da reação em cadeia da polimerase, amplificou-se a sequência do minicírculo do kDNA de L. infantum. Conclui-se que a infecção por L. infantum ocorre em gatos no estado da Paraíba, região Nordeste do Brasil. Deve-se ressaltar a necessidade de compreender o perfil imunológico e epidemiológico da leishmaniose visceral na população felina, com vistas às medidas de controle em saúde pública.(AU)
Assuntos
Animais , Gatos , Gatos/microbiologia , Leishmaniose/microbiologia , Leishmania infantum/patogenicidade , ZoonosesRESUMO
Dogs have been implicated as main reservoirs for visceral leishmaniasis (VL) in urban areas. Therefore, studies on this species provide important data for public health. Thus, the objective of the present study was to ascertain the seroprevalence of canine VL (CVL) and the associated factors in the Brejo Paraibano microregion, northeastern Brazil. A total of 409 dogs were sampled from the eight municipalities of the microregion: Alagoa Grande, Alagoa Nova, Areia, Bananeiras, Borborema, Matinhas, Pilões and Serraria. The diagnosis of CVL was made using an enzyme-linked immunosorbent assay (ELISA S7®), through which the prevalence observed was 29.3%. By robust Poisson regression analysis two factors were associated with seroprevalence: illiterate/incomplete elementary owners education level (prevalence ratio = 1.57; 95% CI = 1.052.34; p-value = 0.027) and tick infestation (prevalence ratio = 1.82; 95% CI = 1.272.61; p-value = 0.001). It is concluded that the seroprevalence of CVL in the Brejo Paraibano microregion is high. The factors associated with seroprevalence indicated the importance to develop socioeducational actions on the population, and the finding that tick infestation was associated with seroprevalence shows that there is a need for investigation regarding the role of ticks in the epidemiology of CVL.(AU)
Os cães são apontados como principais reservatórios da leishmaniose visceral (LV) em áreas urbanas. Portanto, estudos com essa espécie fornecem dados importantes para a saúde pública. Assim, o objetivo do presente estudo foi determinar a soroprevalência da leishmaniose visceral canina (LVC) e os fatores associados na microrregião do Brejo Paraibano, Nordeste do Brasil. Foram amostrados 409 cães dos oito municípios da microrregião: Alagoa Grande, Alagoa Nova, Areia, Bananeiras, Borborema, Matinhas, Pilões e Serraria. O diagnóstico de LVC foi realizado com o ensaio imunoenzimático (kit ELISA S7®), no qual a prevalência observada foi de 29,3%. Pela análise de regressão de Poisson robusta, dois fatores foram associados à soroprevalência: proprietário analfabeto ou com ensino fundamental incompleto (razão de prevalência = 1,57; IC 95% = 1,05-2,34; p-valor = 0,027) e infestação de carrapatos (razão de prevalência = 1,82; IC 95% = 1,27-2,61; p-valor = 0,001). Conclui-se que a soroprevalência da LVC na microrregião Brejo Paraibano é alta. Os fatores associados à soroprevalência indicaram a importância do desenvolvimento de ações socioeducativas na população, e a associação da infestação de carrapatos com a soroprevalência mostra que há necessidade de investigação sobre o papel dos carrapatos na epidemiologia da LVC.(AU)
Assuntos
Animais , Cães , Cães/microbiologia , Leishmania infantum/patogenicidade , Zoonoses/epidemiologiaRESUMO
BACKGROUND: The liver plays a central role in the development of canine visceral leishmaniasis. Studies of natural infection in animals and humans indicate a direct relationship between resolution of infection and the formation and maturation of granulomas in the liver. However, in contrast to other reports in the literature, the present study found no differences in the characteristics of hepatic granulomas that could be related to resistance or susceptibility to Leishmania. Here, we describe the hepatic alterations observed in dogs with differing clinical manifestations of visceral leishmaniasis in an endemic area in the state of Bahia, Brazil. METHODS: We examined 148 animals in an endemic area. The animals were clinically examined, and the infection was determined by ELISA, spleen aspirate culture and quantitative PCR. The animals were grouped into asymptomatic or symptomatic based on the number of signs of LV. The histological liver evaluation was performed in a blinded way. RESULTS: Our results indicated no association between the characteristics of granulomas and clinical presentation. We found an association between the intensity of this inflammatory response and parasite load in the animals' spleens. It is important to note that while hepatic alterations, such as portal and perivascular inflammation and the presence of larger amounts of granulomas, were linked with higher parasite loads, we found the inverse to be true with respect to intrasinusoidal lymphocytosis, the formation of intrasinusoidal inflammatory cell aggregates and Kupffer cell hypertrophy. CONCLUSIONS: Our findings suggest that the presence of mononuclear inflammatory cells inside the sinusoids is more important than that of organized granulomas in terms of the containment of parasitism by the host. We suggest that the presence of granulomas indicates the failure of a first line of defense mechanism in the control of parasite infection, which could be related to the presence of inflammatory cells and Kupffer cell hypertrophy inside the sinusoids. We further demonstrated that dogs with active Leishmania spp. infection present a higher frequency of inflammatory changes in the liver. In addition to being correlated with the severity of clinical manifestation, these hepatic alterations were also associated with changes in hematological and biochemical parameters.
Assuntos
Doenças do Cão/patologia , Leishmania infantum/patogenicidade , Leishmaniose Visceral/veterinária , Fígado/patologia , Animais , Brasil , Doenças do Cão/parasitologia , Cães , Doenças Endêmicas/veterinária , Granuloma/parasitologia , Granuloma/patologia , Granuloma/veterinária , Leishmaniose Visceral/patologia , Fígado/parasitologia , Hepatopatias Parasitárias/parasitologia , Hepatopatias Parasitárias/patologia , Hepatopatias Parasitárias/veterinária , Baço/parasitologiaRESUMO
Visceral leishmaniasis, caused by Leishmania infantum, is a neglected tropical disease, to which efforts in the innovation of effective and affordable treatments remain limited, despite the rising incidence in several regions of the world. In this work, the antileishmanial effects of sugiol were investigated in vitro. This compound was isolated from the bark of Cupressus lusitanica and showed promising activity against L. infantum. In spite of the positive results, it is known that the compound is a poorly water-soluble diterpene molecule, which hinders further investigation, especially in preclinical animal studies. Thus, in an alternative delivery method, sugiol was entrapped in glucan-rich particles obtained from Saccharomyces cerevisiae yeast cell walls (YCWPs). To evaluate the activity of sugiol, the experiments were divided into two parts: (i) the in vitro investigation of antileishmanial activity of free sugiol against L. infantum promastigotes after 24, 48, and 72 h of treatment and (ii) the evaluation of antileishmanial activity of sugiol entrapped in glucan-rich particles against intracellular L. infantum amastigotes. Free sugiol induced the cell-death process in promastigotes, which was triggered by enhancing cytosolic calcium level and promoting the autophagy up to the first 24 h. Over time, the presence of autophagic vacuoles became rarer, especially after treatment with lower concentrations of sugiol, but other cellular events intensified, like ROS production, cell shrinkage, and phosphatidylserine exposure. Hyperpolarization of mitochondrial membrane potential was found at 72 h, induced by the mitochondria calcium uptake, causing an increase in ROS production and lipid peroxidation as a consequence. These events resulted in the cell death of promastigotes by secondary necrosis. Sugiol entrapped in glucan-rich particles was specifically recognized by dectin-1 receptor on the plasma membrane of macrophages, the main host cell of Leishmania spp. Electron micrographs revealed particles containing sugiol within the infected macrophages and these particles were active against the intracellular L. infantum amastigotes without affecting the host cell. Therefore, the YCWPs act like a Trojan horse to successfully deliver sugiol into the macrophage, presenting an interesting strategy to deliver water-insoluble drugs to parasitized cells.
Assuntos
Antiprotozoários/farmacologia , Morte Celular/efeitos dos fármacos , Diterpenos/farmacologia , Leishmania infantum/efeitos dos fármacos , Leishmaniose Visceral/tratamento farmacológico , Animais , Autofagia/efeitos dos fármacos , Cálcio/metabolismo , Parede Celular , Modelos Animais de Doenças , Feminino , Glucanos , Lectinas Tipo C , Leishmania infantum/citologia , Leishmania infantum/patogenicidade , Macrófagos/metabolismo , Potencial da Membrana Mitocondrial , Camundongos Endogâmicos BALB C , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiaeRESUMO
Visceral leishmaniasis is a chronic disease that affects humans and dogs as well. Dogs, the domestic reservoir of Leishmania, play a central role in the transmission of visceral leishmaniasis, the most severe form of this disease. Neutrophils are the most abundant leukocytes in blood and interact with the parasite after infection. Here, we evaluate the effector properties of neutrophils from healthy and naturally Leishmania infantum-infected dogs. Our results showed that the parasite induced neutrophil extracellular trap (NET) release from neutrophils in both groups. Additionally, phagocytosis and NETs contributed differently to parasite killing by neutrophils from healthy and infected animals, and IFN-γ, IL-8, IL-4 and TNF-α production by neutrophils from both groups were differentially modulated by the parasite. Our results contribute to a better understanding of the complex role played by neutrophils in canine visceral leishmaniasis, which may favor the development of more effective therapies.
Assuntos
Leishmania infantum/patogenicidade , Leishmaniose Visceral/veterinária , Neutrófilos/parasitologia , Animais , Doenças do Cão/sangue , Doenças do Cão/parasitologia , Cães , Armadilhas Extracelulares/parasitologia , Feminino , Interferon gama/metabolismo , Interleucina-4/metabolismo , Interleucina-8/metabolismo , Leishmaniose Visceral/sangue , Masculino , Neutrófilos/metabolismo , Fagocitose , Fator de Necrose Tumoral alfa/metabolismoRESUMO
BACKGROUND: Leishmaniasis is a neglected disease endemic in tropical and subtropical areas, with an incidence about 1.6 million cases/year. The first-line treatment of this disease is pentavalent antimony, and the second-line are pentamidine and amphotericin B. All the treatments available cause severe side effects and often have difficulty in accessing parasites within infected cells. STUDY QUESTION: This study aimed to determine if the use of nanoparticles loaded with meglumine antimoniate could reach and targeting infected organs with leishmaniasis, reducing the dosage used and promoting less adverse effects. STUDY DESIGN: This study was performed comparing the meglumine nanoparticle in two experimental groups. The first one healthy mice and the second one inducted mice (leishmaniasis). MEASURES AND OUTCOMES: The nanoparticles loaded with meglumine antimoniate (nanoantimony) were prepared by double-emulsion solvent evaporation method and showed a size of about 150-200 nm. BALB/c mice infected or not with Leishmania amazonensis (cutaneous leishmaniasis model) or Leishmania infantum (visceral leishmaniasis model) was used to access the biodistribution of nanoantimony and meglumine antimoniate labeled with technetium-99m. RESULTS: The biodistribution profiles showed a preferential targeting of the nanoparticles to the liver, spleen, and lungs. Because these are the main organs infected, the nanoparticle may be used for this purpose. The results for cutaneous leishmaniasis showed a low uptake by the lesion (infected region). CONCLUSIONS: The results demonstrated the potential use of these nanoparticles to improve the efficacy of meglumine antimoniate in the treatment of visceral leishmaniasis, indicating their potential as an alternative therapeutic strategy for leishmaniasis infections.
Assuntos
Antiprotozoários/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Visceral/tratamento farmacológico , Antimoniato de Meglumina/administração & dosagem , Animais , Modelos Animais de Doenças , Humanos , Leishmania infantum/patogenicidade , Leishmania mexicana/patogenicidade , Leishmaniose Cutânea/parasitologia , Leishmaniose Visceral/parasitologia , Antimoniato de Meglumina/farmacocinética , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Poliésteres/química , Tecnécio/química , Distribuição Tecidual , Resultado do TratamentoRESUMO
Phlebotomines of the genus Lutzomyia are important vector for species of Leishmania, the etiological agent of leishmaniasis. The aim of this study was to assess the diversity of sandflies in an endemic area for Visceral Leishmaniasis (VL). Sampling was performed in four localities on the coast of the municipality of Goiana, state of Pernambuco, Northeastern Brazil. Specimens were collected monthly on three consecutive nights, from November 2017 to October 2018. CDC light traps were installed at a height of 1.5 m above the ground, in two ecotypes (i.e. tree and animal facility), both in peridomestic areas. A total of 5,205 sandflies were collected, among which the species Lutzomyia longipalpis (99.85%; 5,197/5,205) was the most common, followed by Lutzomyia evandroi (0.13%; 07/5,205) and Lutzomyia whitmani (0.02%; 01/5,205). Specimens of L. longipalpis were collected throughout the study period and most of them were found near to the animal facilities. The findings from this research indicate that vectors for Leishmania infantum are present in the study area throughout the year, along with occurrences of vectors relating to Cutaneous Leishmaniasis (CL). Preventive vector control measures need to be implemented in Goiana to reduce the risk of infection for the human and animal populations.(AU)
Flebotomíneos do gênero Lutzomyia são importantes vetores de espécies de Leishmania, agente etiológico das leishmanioses. O objetivo deste estudo foi avaliar a diversidade de flebotomíneos em área endêmica para Leishmaniose Visceral (LV). As coletas foram realizadas em quatro localidades do litoral do município de Goiana, Pernambuco, Nordeste do Brasil. Os espécimes foram coletados mensalmente em três noites consecutivas de novembro de 2017 a outubro de 2018. Foram instaladas armadilhas luminosas modelo CDC a uma altura de 1,5 m acima do solo em dois ecótopos (ex. árvore e instalações de animais), ambos em áreas peridomiciliares. Um total de 5.205 flebotomíneos foi coletado, sendo Lutzomyia longipalpis (99,85%; 5.197/5.205) a mais comum, seguida por Lutzomyia evandroi (0,13%; 07/5.205) e Lutzomyia whitmani (0,02%; 01/5.205). L. longipalpis foi coletada durante todo o período do estudo. A maioria dos espécimes foi detectada perto das instalações dos animais. Os achados deste estudo indicam a presença de vetores de Leishmania infantum na área avaliada ao longo do ano, bem como a ocorrência de vetores relacionados à Leishmaniose Cutânea (LC). Medidas preventivas de controle vetorial devem ser implementadas em Goiana para reduzir o risco de infecção à população humana e animal.(AU)
Assuntos
Humanos , Animais , Leishmaniose/classificação , Leishmaniose/diagnóstico , Leishmaniose/prevenção & controle , Psychodidae/microbiologia , Leishmania infantum/patogenicidadeRESUMO
Visceral leishmaniasis (VL) still represents a serious public health problem in Brazil due to the inefficiency of the control measures currently employed, that included early diagnosis and treatment of human cases, vector control, euthanasia of infected dogs and, recently approved in Brazil, treatment with Milteforam drug. Effective clinical management depend largely on early and unequivocal diagnosis, however, cross-reactivity have also been described in serological tests, especially when it refers to individuals from areas where Chagas' disease is also present. Thus, to discover new antigens to improve the current serological tests for VL diagnosis is urgently needed. Here, we performed an immunogenomic screen strategy to identify conserved linear B-cell epitopes in the predicted L. infantum proteome using the following criteria: i) proteins expressed in the stages found in the vertebrate host, amastigote stage, and secreted/excreted, to guarantee greater exposure to the immune system; ii) divergent from proteins present in other infectious disease pathogens with incidence in endemic areas for VL, as T. cruzi; iii) highly antigenic to humans with different genetic backgrounds, independently of the clinical stage of the disease; iv) stable and adaptable to quality-control tests to guarantee reproducibility; v) using statistical analysis to determine a suitable sample size to evaluate accuracy of diagnostic tests established by receiver operating characteristic strategy. We selected six predicted linear B-cell epitopes from three proteins of L. infantum parasite. The results demonstrated that a mixture of peptides (Mix IV: peptides 3+6) were able to identify VL cases and simultaneously able to discriminate infections caused by T. cruzi parasite with high accuracy (100.00%) and perfect agreement (Kappa index = 1.000) with direct methods performed by laboratories in Brazil. The results also demonstrated that peptide-6, Mix III (peptides 2+6) and I (peptides 2+3+6) are potential antigens able to used in VL diagnosis, represented by high accuracy (Ac = 99.52%, 99.52% and 98.56%, respectively). This study represents an interesting strategy for discovery new antigens applied to serologic diagnosis which will contribute to the improvement of the diagnosis of VL and, consequently, may help in the prevention, control and treatment of the disease in endemic areas of Brazil.
Assuntos
Antígenos de Protozoários/sangue , Diagnóstico Precoce , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/sangue , Animais , Antígenos de Protozoários/imunologia , Brasil , Doença de Chagas/sangue , Doença de Chagas/imunologia , Doença de Chagas/parasitologia , Reações Cruzadas , Testes Diagnósticos de Rotina , Doenças do Cão/sangue , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Cães , Ensaio de Imunoadsorção Enzimática , Humanos , Imunogenética/métodos , Leishmania infantum/imunologia , Leishmania infantum/patogenicidade , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/parasitologia , Testes SorológicosRESUMO
In Honduras visceral leishmaniasis and non-ulcerated or atypical cutaneous leishmaniasis (NUCL) are caused by the species Leishmania (L.) infantum chagasi. NUCL is the most common clinical form in the southern regions of the country, mainly affecting the young. In view of the lack of knowledge about the pathogenesis of the disease pattern caused by L. (L) infantum chagasi in individuals affected by NUCL, the aim of the present study was to describe in detail the histopathological features of the skin lesion caused by the parasite. Biopsies from human NUCL lesions with a positive parasitological diagnosis were collected and processed using standard histological techniques. Paraffin sections stained by haematoxylin and eosin were used to examine the histopathological alterations seen in the skin. The lesions varied between 3 and 5 mm, and the majority of the patients (60%) had a single lesion. Lesions were more frequently seen in females (65%), with an average age of 33.4 years. Microscopically, the skin lesions were characterized by mononuclear inflammatory infiltrate in the dermis composed of lymphocytes, macrophages and a few plasma cells. The intensity of the infiltration varied from discrete to intense. In both cases, the parasitic infection was discrete. Granulomas were present in 60% of cases and were associated with intense inflammation. The data revealed by the histopathological alterations in the skin of individuals affected by NUCL suggest activation of a cellular immune response that potentially controls parasite spreading.