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1.
BMC Infect Dis ; 20(1): 946, 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33308170

RESUMO

BACKGROUND: Direct agglutination test (DAT) as a simple, accurate and reliable method, has been widely used for serodiagnosis of visceral leishmaniasis (VL) during the last three decades. The present study is a systematic review and meta-analysis to evaluate the diagnostic accuracy of DAT for serodiagnosis of human VL. METHODS: Electronic databases, including MEDLINE (via PubMed), SCOPUS, Web of Science, SID and Mag Iran (two Persian scientific search engines) were searched from December 2004 to April 2019. We determined the pooled sensitivity and specificity rates of DAT for the diagnosis of human VL, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic (ROC) curves parameters across the eligible studies. RESULTS: Of the 2928 records identified in the mentioned electronic databases and after examining reference lists of articles, 24 articles met inclusion criteria and were enrolled in the systematic review and out of them 20 records qualified for meta-analysis. The pooled sensitivity and specificity rates of DAT was 96% [95% CI, 92-98] and 95% [CI95% 86-99], respectively. The likelihood ratio of a positive test (LR+) was found to be 21 [CI95%, 6.6-66.5] and the likelihood ratio of a negative test (LR-) was found to be 0.04 [(CI95%, 0.02-0.08]. The combined estimate of the diagnostic odds ratio for DAT was high [467 (CI95%, 114-1912]). We found that the summary receiver operating characteristic curve (SROC) is positioned near the upper left corner of the curve and the area under curve (AUC) was 0.98 (95% CI, 0.97 to 0.99). CONCLUSION: Referring to our analysis, we determined that DAT can be considered as a valuable tool for the serodiagnosis of human VL with high sensitivity and specificity. As DAT is a simple, accurate and efficient serological test, it can be recommended for serodiagnosis of human VL particularly in endemic areas.


Assuntos
Testes de Aglutinação/métodos , Confiabilidade dos Dados , Leishmania donovani/imunologia , Leishmaniose Visceral/diagnóstico , Humanos , Leishmaniose Visceral/parasitologia , Razão de Chances , Curva ROC , Sensibilidade e Especificidade
2.
PLoS Negl Trop Dis ; 14(12): e0008947, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33338041

RESUMO

Leishmaniasis is among the world's most neglected diseases. Dogs are the main reservoirs/hosts of Leishmania infantum, causative agent of both canine and human visceral leishmaniosis. Canine leishmaniasis (CanL) represents a public health problem as one of the most prevalent zoonotic diseases worldwide. Current therapeutics present drawbacks; thus, there is a need for more effective, safer, and cheaper drugs. The aim of this study was to evaluate and to compare the efficacy of oral administration of artesunate or meglumine antimoniate/allopurinol in dogs with clinical leishmaniasis. Forty-two dogs with naturally occurring clinical leishmaniasis were included in this open-label, simple randomized positive-control clinical field trial with 6 months of follow-up. Dogs received meglumine antimoniate 100 mg/kg/day and allopurinol 30 mg/kg/day for 28 days (control group, n = 26) or artesunate 25 mg/kg/day for 6 days (test group, n = 16). The animals were evaluated for their clinical evolution, parasite load (by qPCR) and humoral response at different time points: 0, 30, 90, and 180 days after treatment. Data analyses showed a significant improvement in both groups in clinical scores, parasitemia and antibody titers after treatment. Compared to the control group, the artesunate group showed significantly lower clinical score (P = 0.0001), lower parasitemia (P = 0.0001) and antibody titers after 6 months of follow-up. Compared to baseline values, a rapid, significant reduction (P < 0.012) in antibody levels, 2.28- versus 3.04-fold for the control versus artesunate groups, respectively, was observed 30 days after treatment. Antibody levels continued to decrease further in the artesunate group, where 58% of cases became seronegative at the 6-month follow-up. All qPCR-positive dogs were negative after treatment with artesunate, while 14.3% remained positive with the appearance of two new cases in the control group. Artesunate was well tolerated, and no side effects were recorded. Treatment failures were similar in both groups with 27.27% (6/22), including 18.18% (4/22) mortality in the control group, versus 26.66% (4/15), including 13.33% (2/15) mortality in the artesunate group. This is the first report showing the potential of artesunate in the treatment of dogs with clinical leishmaniasis. Artesunate showed higher efficacy than the current first-line treatment for CanL without any adverse effects. It could be a good alternative chemotherapy for CanL, and may be considered for further studies in human leishmaniases. Further clinical trials are needed to confirm these findings, to determine if there are relapses after treatment and if dogs remain infective to sandflies, to define the ideal therapeutic dosage and duration of treatment with artesunate.


Assuntos
Alopurinol/uso terapêutico , Antiprotozoários/uso terapêutico , Artesunato/uso terapêutico , Doenças do Cão/tratamento farmacológico , Leishmania infantum/efeitos dos fármacos , Leishmaniose Visceral/veterinária , Antimoniato de Meglumina/uso terapêutico , Animais , Doenças do Cão/parasitologia , Cães , Feminino , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/parasitologia , Masculino , Carga Parasitária/veterinária , Parasitemia/tratamento farmacológico , Zoonoses
3.
PLoS Negl Trop Dis ; 14(12): e0008963, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33382690

RESUMO

Diagnosis of a first-time visceral leishmaniasis (VL) infection in Ethiopia is established by use of a rapid diagnostic test (RDT) detecting antibodies against rK39, direct agglutination test (DAT) and microscopy according to the national algorithm. The performance of individual tests and algorithm is variable and depends on several factors, one being HIV status. Limited data are available on the performance of tests in VL-HIV coinfected patients. Assessment of the performance of DAT (ITM-A), rK39 ELISA (Serion) and six RDT (Onsite Leishmania Ab CTK, Antigen ICT Xinjier, IT Leish Biorad, Kalazar Detect Inbios, rK39 IgG1 Coris, rk28 IgG1 Coris) for the diagnosis of VL was done on a panel of 91 stored serum and plasma samples of 'first-episode' suspected VL patients, with HIV coinfection (n = 51) and without (n = 40). A combined reference standard was used: either positive microscopy on tissue aspirates, or in case of negative microscopy, positive PCR results on the aspirate slide. Additionally, endemic healthy controls (n = 20), non-endemic controls (n = 10) and patients with confirmed malaria infection (n = 10) were tested for specificity evaluation. Sensitivities ranged from 69.2% for DAT (applied cut-off ≥ 1/3200) to 92.2% for the Onsite RDT, whereas specificities ranged from 20.0% for Kalazar Antigen ICT to 100% for IT Leish and rK39 IgG1. Sensitivities from all assays decreased upon stratification according to HIV status but was only significantly different for rK39 Serion ELISA (p-value 0.0084) and the Onsite RDT (p-value 0.0159). In conclusion, performance of commercially available assays for VL on samples from Northern-Ethiopian patients varied widely with a substantial decrease in sensitivity in the VL-HIV coinfected group. Clear guidelines on minimal performance criteria of individual tests and algorithms are needed, as well as which reference standard should be used to determine the performance.


Assuntos
Antígenos de Protozoários/imunologia , Infecções por HIV/complicações , Leishmania/imunologia , Leishmaniose Visceral/diagnóstico , Testes de Aglutinação , Testes Diagnósticos de Rotina , Ensaio de Imunoadsorção Enzimática , Etiópia/epidemiologia , Humanos , Leishmaniose Visceral/parasitologia , Padrões de Referência
4.
Am J Trop Med Hyg ; 103(5): 1927-1929, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32959758

RESUMO

Visceral leishmaniasis (VL) is a systemic infection caused by the protozoal parasite Leishmania, spread via the bloodstream to the reticuloendothelial system, through the bite of the sand fly. It is endemic in parts of Africa, South America, Asia, and Europe, including the Mediterranean. Here, we describe a case of VL that was initially diagnosed as Q fever based on positive Coxiella burnetii serology and showed a partial response to doxycycline treatment.


Assuntos
Coxiella burnetii/imunologia , Doxiciclina/uso terapêutico , Leishmania donovani/imunologia , Leishmaniose Visceral/diagnóstico por imagem , Abdome/diagnóstico por imagem , Animais , Diagnóstico Diferencial , Hepatomegalia/diagnóstico por imagem , Humanos , Leishmania donovani/isolamento & purificação , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/parasitologia , Masculino , Febre Q/diagnóstico por imagem , Esplenomegalia/diagnóstico por imagem , Tórax/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto Jovem
5.
Am J Trop Med Hyg ; 103(5): 1930-1933, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32959759

RESUMO

There has been increased interest in using metagenomic next-generation sequencing as an unbiased approach for diagnosing infectious diseases. We describe a 61-year-old man on fingolimod therapy for multiple sclerosis with an extensive travel history who presented with 7 months of fevers, night sweats, and weight loss. Peripheral blood tests showed pancytopenia and abnormal acute phase reactants. A bone marrow aspirate showed the presence of numerous intracellular and extracellular amastigotes consistent with visceral leishmaniasis (VL). Metagenomic sequencing of the bone marrow aspirate confirmed Leishmania infantum, a species widely reported in the Mediterranean region. This correlated with acquisition of VL infection during the patient's most recent epidemiological exposure in southern Italy 12 months prior. This case demonstrates the potential application of metagenomic sequencing for identification and speciation of Leishmania in cases of VL; however, further assessment is required using other more readily obtained clinical samples such as blood.


Assuntos
Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/diagnóstico , Metagenômica , Medula Óssea/parasitologia , Humanos , Hospedeiro Imunocomprometido , Itália , Leishmania infantum/genética , Leishmaniose Visceral/parasitologia , Masculino , Pessoa de Meia-Idade , Viagem
6.
Exp Parasitol ; 218: 107987, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32891601

RESUMO

The protozoan parasite Leishmania spp. causes leishmaniases, a group of diseases creating serious health problems in many parts of the world with significant resistance to existing drugs. Insect derived antimicrobial peptides are promising alternatives to conventional drugs against several human disease-causing pathogens because they do not generate resistance. Halictine-2, a novel antimicrobial peptide from the venom of eusocial honeybee, Halictus sexcinctus showed significant anti-leishmanial activity in vitro, towards two life forms of the dimorphic parasite, the free-swimming infective metacyclic promastigotes and the intracellular amastigotes responsible for the systemic infection. The anti-leishmanial activity of the native peptide (P5S) was significantly enhanced by serine to threonine substitution at position 5 (P5T). The peptide showed a propensity to form α-helices after substitution at position-5, conferring amphipathicity. Distinct pores observed on the promastigote membrane after P5T exposure suggested a mechanism of disruption of cellular integrity. Biochemical alterations in the promastigotes after P5T exposure included generation of increased oxygen radicals with mitochondrial Ca2+ release, loss of mitochondrial membrane potential, reduction in total ATP content and increased mitochondrial mass, resulting in quick bioenergetic and chemiosmotic collapse leading to cell death characterized by DNA fragmentation. P5T was able to reduce intracellular amastigote burden in an in vitro model of Leishmania infection but did not alter the proinflammatory cytokines like TNF-α and IL-6. The ability of the P5T peptide to kill the Leishmania parasite with negligible haemolytic activity towards mouse macrophages and human erythrocytes respectively, demonstrates its potential to be considered as a future antileishmanial drug candidate.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Antiprotozoários/farmacologia , Apoptose , Leishmania tropica/efeitos dos fármacos , Substituição de Aminoácidos , Animais , Peptídeos Catiônicos Antimicrobianos/química , Antiprotozoários/química , Venenos de Abelha/química , Cálcio/análise , Cálcio/metabolismo , Linhagem Celular , Dicroísmo Circular , Fragmentação do DNA , Fluoresceína-5-Isotiocianato , Corantes Fluorescentes , Fluorometria , Humanos , Leishmania tropica/ultraestrutura , Leishmaniose Visceral/parasitologia , Macrófagos Peritoneais , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Confocal , Microscopia Eletrônica de Varredura , Mitocôndrias/química , Tamanho Mitocondrial , Espécies Reativas de Oxigênio/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Superóxidos/isolamento & purificação
7.
PLoS Negl Trop Dis ; 14(8): e0008575, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32866156

RESUMO

BACKGROUND: Treatment failure and resistance to the commonly used drugs remains a major obstacle for successful chemotherapy against visceral leishmaniasis (VL). Since the development of novel therapeutics involves exorbitant costs, the effectiveness of the currently available antitrypanosomatid drug suramin has been investigated as an antileishmanial, specifically for VL,in vitro and in animal model experiments. METHODOLOGY/PRINCIPAL: Leishmania donovani promastigotes were treated with suramin and studies were performed to determine the extent and mode of cell mortality, cell cycle arrest and other in vitro parameters. In addition, L. donovani infected BALB/c mice were administered suramin and a host of immunological parameters determined to estimate the antileishmanial potency of the drug. Finally, isothermal titration calorimetry (ITC) and enzymatic assays were used to probe the interaction of the drug with one of its putative targets namely parasitic phosphoglycerate kinase (LmPGK). FINDINGS: The in vitro studies revealed the potential efficacy of suramin against the Leishmania parasite. This observation was further substantiated in the in vivo murine model, which demonstrated that upon suramin administration, the Leishmania infected BALB/c mice were able to reduce the parasitic burden and also generate the host protective immunological responses. ITC and enzyme assays confirmed the binding and consequent inhibition of LmPGK due to the drug. CONCLUSIONS/SIGNIFICANCE: All experiments affirmed the efficacy of suramin against L. donovani infection, which could possibly lead to its inclusion in the repertoire of drugs against VL.


Assuntos
Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Leishmaniose Visceral/tratamento farmacológico , Suramina/farmacologia , Suramina/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Citocinas/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Concentração Inibidora 50 , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/parasitologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Fosfoglicerato Quinase/efeitos dos fármacos , Células RAW 264.7/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
8.
Acta Vet Scand ; 62(1): 42, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32746875

RESUMO

Canine vector-borne diseases are caused by pathogens transmitted by arthropods including ticks, mosquitoes and sand flies. Many canine vector-borne diseases are of zoonotic importance. This study aimed to assess the prevalence of vector-borne infections caused by Dirofilaria immitis, Ehrlichia canis, Borrelia burgdorferi sensu lato, Anaplasma spp. and Leishmania infantum in a dog kennel in Argeș County, Romania. Dog kennels are shelters for stray dogs with no officially registered owners that are gathered to be neutered and/or boarded for national/international adoptions by various public or private organizations. The international dog adoptions might represent a risk in the transmission of pathogens into new regions. In this context, a total number of 149 blood samples and 149 conjunctival swabs from asymptomatic kennel dogs were assessed using serology and quantitative real-time polymerase chain reaction. Antibodies against B. burgdorferi s.l. were detected in one dog (0.6%), anti-Anaplasma antibodies were found in five dogs (3.3%), while ten dogs (6.7%) tested positive for D. immitis antigen. Overall, 20.1% (30/149) of dogs were positive for L. infantum DNA. All samples were seronegative for anti-Leishmania antibodies. When adopting dogs from this region of Romania, owners should be aware of possible infection with especially L. infantum. The travel of infected dogs may introduce the infection to areas where leishmaniasis is not present.


Assuntos
Anaplasmose/epidemiologia , Doenças do Cão/epidemiologia , Ehrlichiose/veterinária , Leishmaniose Visceral/veterinária , Doença de Lyme/veterinária , Anaplasma/isolamento & purificação , Anaplasmose/microbiologia , Animais , Anticorpos Antibacterianos/análise , Borrelia burgdorferi/isolamento & purificação , DNA de Protozoário/análise , Vetores de Doenças , Doenças do Cão/microbiologia , Doenças do Cão/parasitologia , Cães , Ehrlichia canis/isolamento & purificação , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologia , Feminino , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Doença de Lyme/epidemiologia , Doença de Lyme/microbiologia , Masculino , Prevalência , Romênia/epidemiologia
9.
Parasitol Res ; 119(9): 2991-3003, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32748038

RESUMO

Visceral leishmaniasis (VL, also known as kala-azar) is a vector borne disease caused by obligate intracellular protozoan parasite Leishmania donovani. To overcome the limitations of currently available drugs for VL, molecular target-based study is a promising tool to develop new drugs to treat this neglected tropical disease. One such target we recently identified from L. donovani (Ld) genome (WGS, clinical Indian isolate; BHU 1220, AVPQ01000001) is a small GTP-binding protein, Rab6 protein. We now report a specific inhibitor of the GTPase activity of Rab6 protein of L. donovani (LdRab6) without restricting host enzyme activity. First, to understand the nature of LdRab6 protein, we generated recombinant LdRab6 mutant proteins (rLdRab6) by systematically introducing deletion (two cysteine residues at C-terminal) and mutations [single amino acid substitutions in the conserved region of GTP (Q84L)/GDP(T38N) coding sequence]. The GTPase activity of rLdRab6:GTP and rLdRab6:GDP locked mutant proteins showed ~ 8-fold and ~ 1.5-fold decreases in enzyme activity, respectively, compared to the wild type enzyme activity. The mutant protein rLdRab6:ΔC inhibited the GTPase activity. Sequence alignment analysis of Rab6 protein of L. donovani with Homo sapiens showed identical amino acids in the G conserved region (GTP/GDP-binding sites) but it differed in the C-terminal region. We then evaluated the inhibitory activity of trans-dibenzalacetone (DBA, a synthetic analog of curcumin with strong antileishmanial activity reported earlier by us) in the GTPase activity of LdRab6 protein. Comparative molecular docking analysis of DBA and specific inhibitors of Rab proteins (Lovastatin, BFA, Zoledronate, and NE10790) indicated that DBA had optimum binding affinity with LdRab6 protein. This was further confirmed by the GTPase activity of DBA-treated LdRab6 which showed a basal GTP level significantly lower than that of the wild-type rLdRab6. The results confirm that DBA inhibits the GTPase activity of LdRab6 protein from L. donovani (LdRab6), a potential target for its antileishmanial effect.


Assuntos
Antiprotozoários/farmacologia , Inibidores Enzimáticos/farmacologia , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/parasitologia , Pentanonas/farmacologia , Proteínas de Protozoários/antagonistas & inibidores , Proteínas rab de Ligação ao GTP/antagonistas & inibidores , Sequência de Aminoácidos , Sítios de Ligação , Curcumina/farmacologia , Humanos , Leishmania donovani/química , Leishmania donovani/enzimologia , Leishmania donovani/genética , Leishmaniose Visceral/tratamento farmacológico , Simulação de Acoplamento Molecular , Pentanonas/química , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Alinhamento de Sequência , Proteínas rab de Ligação ao GTP/química , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo
10.
Mikrobiyol Bul ; 54(3): 429-443, 2020 Jul.
Artigo em Turco | MEDLINE | ID: mdl-32755519

RESUMO

Although asexual reproduction has been attributed to Leishmania species, genetic exchange has recently been demonstrated, which helped emerging of hybrid isolates. Situated on the crossroads between three continents, Leishmania hybrids may be present in Turkey. In Turkey, visceral leishmaniasis caused by Leishmania infantum is less common, while cutaneous leishmaniasis (CL) caused by Leishmania tropica and L.infantum could reach 2500 reported cases a year. Our aim was to investigate genetic variability of local Leishmania species and presence of hybrid Leishmania strains in Turkey. Twenty CL patients from Sanliurfa and Hatay, where only L.tropica and both L.tropica and L.infantum cause CL, respectively, were registered equally. All isolates were assessed with real-time polymerase chain reaction (Rt-PCR), isoenzyme analysis, gene sequencing, two-dimensional gel electrophoresis (2D-PAGE) and MALDI-TOF/TOFMS followed by in vivo analyses on mouse model. Identification of differentially expressed proteins was performed. These proteins were confirmed by sequence analysis. All isolates from Sanliurfa were found to be L.tropica which caused cutaneous infection in mice. However, one of 10 isolates from Hatay was found as Leishmania major which caused cutaneous infection. Five isolates were found as L.tropica with Rt-PCR and gene sequencing, one of which had one different protein from the reference L.tropica strain and caused cutaneous infection. Four of the five isolates had five different proteins compared to reference strain and caused both cutaneous and visceral infections. Remaining four isolates showed double melting curves in Rt-PCR, which were concordant with L.tropica and L.infantum. Their sequencing and isoenzyme analyses indicated them as L.infantum. They had six different proteins compared to reference L.infantum strain and caused cutaneous and visceral infections. It is concluded that the isolates with different proteins were hybrid Leishmania species. In the present study, outcomes of the proteomics, genomics, clinical manifestations and tissue tropism on animal models were evaluated together for the first time. In addition to L.tropica and L.infantum, L.major was identified as a causative agent for CL and hybrids of L.infantum/tropica were also shown to be present.


Assuntos
Variação Genética , Leishmania , Leishmaniose Cutânea , Leishmaniose Visceral , Animais , Modelos Animais de Doenças , Humanos , Leishmania/genética , Leishmaniose Cutânea/parasitologia , Leishmaniose Visceral/parasitologia , Camundongos , Turquia
11.
PLoS One ; 15(8): e0236414, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32845890

RESUMO

Visceral leishmaniasis (VL) is a common infectious disease that is endemic in Iran. This study aimed to investigate the spatial autocorrelation of VL in the northwest of Iran. In this cross-sectional study, the data of all patients were collected in 2009-2017 and analyzed by SPSS23 and Moran's and General G Index. The MaxEnt3.3.3 software was used to determine the ecological niche. A big hot spot area was identified in five counties in the northwest of Iran. More than 70% of the cases were reported from these regions, and the incidence rate increased in the northwest of Iran from 2013 to 2017. Seasonal rainfall and average daily temperature were the most important climate variables affecting the incidence of VL in this region (p < 0.05). Therefore, it can be concluded that VL in the northwest of Iran is expanding to new areas along the border with the Republic of Azerbaijan, and the northeastern section of this region is a high-risk area.


Assuntos
Ecossistema , Doenças Endêmicas/prevenção & controle , Leishmaniose Visceral/epidemiologia , Análise Espacial , Azerbaijão/epidemiologia , Clima , Humanos , Irã (Geográfico)/epidemiologia , Leishmaniose Visceral/parasitologia , Inquéritos e Questionários
12.
Parasitol Res ; 119(10): 3541-3548, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32803333

RESUMO

The aim of this study was to evaluate, through qPCR, the prevalence of parasitemia in sick kennel dogs naturally infected by canine leishmaniasis. An evaluation of daily changes of the parasitic load in peripheral blood was also performed. A comprehensive clinical examination and the collection of several samples (blood, lymph node, skin, and conjunctiva) were performed in 140 dogs living in an endemic area. Among these, only the dogs with clinically evident leishmaniasis were enrolled (39/140; 27.9%). Twelve (30.8%) out of 39 showed parasitemia, with a low load (median: 4 Leishmania/ml) despite a high lymph node parasite load (median: 4000 Leishmania/ml) and high IFAT titers (≥ 1:640). Seven sick dogs were sampled every 4 h for 6 times during a 24-h period, in order to obtain light- and dark-span samples. Only one (14.3%) out of the seven serial sampled dogs showed Leishmania DNA in the peripheral blood in two samples (2/42; 4.8%). Surprisingly, Leishmania DNA was also detected in the peripheral blood of asymptomatic dogs, negative to both serology and PCR performed on samples other than blood (6/101; 5.9%). The present study confirms that in canine leishmaniasis parasitemia is uncommon and even transitory. Even if recommended, microscopic examination is confirmed as a low sensitivity method with a lower diagnostic utility in canine leishmaniasis than qPCR. Moreover, circulating Leishmania DNA can be found even in healthy dogs. This finding is important in clinical practice because in endemic areas it suggests a transfusion risk and a possible transmission to the vector.


Assuntos
Doenças do Cão/parasitologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Parasitemia/veterinária , Animais , DNA de Protozoário/sangue , DNA de Protozoário/genética , Doenças do Cão/epidemiologia , Cães , Leishmania infantum/genética , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Carga Parasitária/veterinária , Parasitemia/epidemiologia , Parasitemia/parasitologia , Prevalência , Reação em Cadeia da Polimerase em Tempo Real/veterinária
13.
Parasitol Res ; 119(9): 3041-3051, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32779021

RESUMO

Our objective was to investigate clinical progression, presence of parasites and DNAs, parasite loads, and histological alterations in BALB/c mice and Syrian golden hamsters after intraperitoneal inoculation with Leishmania (Mundinia) martiniquensis promastigotes with a goal to choosing an appropriate animal model for visceral leishmaniasis. Infections were monitored for 16 weeks. Infected BALB/c mice were asymptomatic during the infection course. Parasite DNAs were detected in the liver at week 8 of infection, followed by clearance in most animals at week 16; whereas in the spleen, parasite DNAs were detected until week 16. These results are correlated to those obtained measuring parasite loads in both organs. No parasite DNA and no alteration in the bone marrow were observed indicating that no dissemination occurred. These results suggest the control of visceralization of L. martiniquensis by BALB/c mice. In hamsters, weight loss, cachexia, and fatigue were observed after week 11. Leishmania martiniquensis parasites were observed in tissue smears of the liver, spleen, and bone marrow by week 16. Parasite loads correlated with those from the presence of parasites and DNAs in the examined tissues. Alterations in the liver with nuclear destruction and cytoplasmic degeneration of infected hepatocytes, presence of inflammatory infiltrates, necrosis of hepatocytes, and changes in splenic architecture and reduction and deformation of white pulp in the spleen were noted. These results indicate a chronic form of visceral leishmaniasis indicating that the hamster is a suitable animal model for the study of pathological features of chronic visceral leishmaniasis caused by L. martiniquensis.


Assuntos
Leishmania/fisiologia , Leishmaniose Visceral/parasitologia , Animais , Cricetinae , Modelos Animais de Doenças , Humanos , Leishmania/genética , Fígado/parasitologia , Masculino , Mesocricetus , Camundongos , Camundongos Endogâmicos BALB C , Carga Parasitária , Baço/parasitologia
14.
Am J Trop Med Hyg ; 103(5): 1938-1941, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32815498

RESUMO

Interleukin-10 (IL-10) and interleukin-27 (IL-27) both exert counterregulatory immunodeactivation in visceral Leishmania donovani infection. We studied experimental L. donovani infection in the livers of IL-10-/- and IL-27Rα-/- mice and observed that in IL-27Rα-/-, but not IL-10-/- mice, interferon-gamma (IFN-γ) and tumor necrosis factor (TNF) were required for heightened granulomatous inflammation and accelerated control of intracellular parasite replication. This difference in mechanism, along with residual IL-10 activity in IL-27Rα-/- mice, suggested targeting IL-27 in addition to IL-10 in a macrophage-activating, anti-counterregulatory cytokine treatment strategy. In C57BL/6 wild-type mice with established liver infection, a single injection of anti-IL-27 p28 or anti-IL-10R monoclonal antibody enhanced granuloma assembly, enabled macrophage activation, and induced comparable parasite killing (49-56%). However, anti-IL-27 p28 plus anti-IL-10R combination treatment did not increase leishmanicidal effects. These results suggest that IL-27 and IL-10 may operate in a linked deactivating mechanism and that in this intracellular infection, either IL-27 or IL-10 is a suitable immunotherapeutic target.


Assuntos
Interleucina-10/metabolismo , Interleucinas/metabolismo , Leishmania donovani/imunologia , Leishmaniose Visceral/tratamento farmacológico , Animais , Citocinas/imunologia , Modelos Animais de Doenças , Feminino , Humanos , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/patologia , Fígado/imunologia , Fígado/parasitologia , Fígado/patologia , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL
15.
PLoS Negl Trop Dis ; 14(7): e0007986, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32716941

RESUMO

Genetic polymorphisms in natural Leishmania populations have been reported in endemic areas. Microsatellite typing is a useful tool to elucidate the genetic variability of parasite strains, due to its capability for high-resolution mapping of genomic targets. The present study employed multilocus microsatellite typing (MLMT) to explore the genotypic composition of Leishmania infantum in naturally infected dogs by genotyping parasites infecting different tissues with or without in vitro expansion. Eighty-six samples were collected from 46 animals in an endemic region of visceral leishmaniasis (VL). MLMT was performed for 38 spleen samples and 48 L. infantum cultures isolated from different tissues. Of the 86 samples, 23 were effectively genotyped by MLMT, identifying nine multilocus genotypes (MLG; referred to as MLG A-I). MLGs A, B and C were detected in more than one type of tissue and in more than one sample. Conversely, MLG D-I were uniquely detected in one sample each. The results showed that multiple genotype infections occur within a single host and tissue. Paired sample analysis revealed the presence of different MLMT alleles in 14 dogs, while the same MLG allele was present in 15 animals. STRUCTURE analysis demonstrated the presence of two populations; 13 samples displayed a similar admixture of both ancestral populations, and these were not assigned to any population. Only samples for which Q ≥ 0.70 after CLUMPP alignment were considered to be part of Population 1 (POP1) or Population 2 (POP2). POP2 comprised the majority of samples (n = 54) compared to POP1 (n = 19). This study presents evidence of multiple genotype infections (caused by L. infantum) in dogs in an area with high VL transmission. Further investigations must be undertaken to determine the effects of multiple infection on the host immune response and disease dynamics and treatment.


Assuntos
Doenças do Cão/parasitologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Animais , Cães , Feminino , Variação Genética , Genótipo , Leishmania infantum/classificação , Leishmania infantum/genética , Leishmaniose Visceral/parasitologia , Masculino , Repetições de Microssatélites , Filogenia
16.
PLoS Negl Trop Dis ; 14(7): e0008396, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32722702

RESUMO

The parasitophorous vacuoles (PVs) that insulate Leishmania spp. in host macrophages are vacuolar compartments wherein promastigote forms differentiate into amastigote that are the replicative form of the parasite and are also more resistant to host responses. We revisited the biogenesis of tight-fitting PVs that insulate L. infantum in promastigote-infected macrophage-like RAW 264.7 cells by time-dependent confocal laser multidimensional imaging analysis. Pharmacological disassembly of the cellular microtubule network and silencing of the dynein gene led to an impaired interaction of L. infantum-containing phagosomes with late endosomes and lysosomes, resulting in the tight-fitting parasite-containing phagosomes never transforming into mature PVs. Analysis of the shape of the L. infantum parasite within PVs, showed that factors that impair promastigote-amastigote differentiation can also result in PVs whose maturation is arrested. These findings highlight the importance of the MT-dependent interaction of L. infantum-containing phagosomes with the host macrophage endolysosomal pathway to secure the intracellular fate of the parasite.


Assuntos
Leishmania infantum/fisiologia , Leishmaniose Visceral/parasitologia , Macrófagos/parasitologia , Microtúbulos/parasitologia , Animais , Endossomos/metabolismo , Humanos , Leishmania infantum/crescimento & desenvolvimento , Leishmaniose Visceral/metabolismo , Camundongos , Microtúbulos/metabolismo , Fagossomos/metabolismo , Células RAW 264.7
17.
Int J Infect Dis ; 98: 470-477, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32645376

RESUMO

OBJECTIVES: Visceral leishmaniasis (VL) is a progressive disease that, left untreated, is typically fatal. The purpose of this investigation was to detect Leishmania sp. infection in hemodialysis patients who had received multiple blood transfusions at a private clinic in Campo Grande, Mato Grosso do Sul state, Midwest Brazil. METHODS: Fifty randomly selected volunteers were interviewed for collection of demographic, socioeconomic, and epidemiological data. Indirect immunofluorescence (titers positive when ≥1:40) and rK39 immunochromatographic tests were employed for serological investigation. RESULTS: Males predominated (60%). Age ranged from 20 to 77 years. Most subjects reported being on hemodialysis for at least one year (94%) and 84% were candidates for kidney transplantation, 67% of whom were on the waiting list. Leishmania sp. infection was detected in 32%. Contact with infected dogs was the only variable associated with infection. CONCLUSIONS: Under immunocompromised conditions, VL is opportunistic and potentially fatal. Despite existing risks, screening for VL is not performed in asymptomatic donors and recipients. The detection of anti-Leishmania antibodies in these patients reinforces the need for infection screening before immunosuppressive treatment is initiated to reduce not only the risks of VL development and severity, but also mortality rates in cases of reactivation of latent infection.


Assuntos
Anticorpos Antiprotozoários/sangue , Leishmania/imunologia , Leishmaniose Visceral/sangue , Adulto , Idoso , Animais , Brasil , Cães , Seleção do Doador , Feminino , Humanos , Transplante de Rim , Leishmania/fisiologia , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/parasitologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
18.
Exp Parasitol ; 217: 107947, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32628971

RESUMO

Visceral leishmaniasis (VL) is an infectious disease caused by the protozoan parasite Leishmania (Leishmania) infantum, an intracytoplasmic parasite that affects humans and other species of domestic and wild mammals. In Brazil, the treatment of canine visceral leishmaniasis (CVL) with miltefosine has been implemented since 2016, and the reports on the clinical and immunological conditions of treated dogs are scarce. Thus, this study aimed to assess and monitor the clinical, laboratory, and immunological condition of dogs with CVL before (D0) and after (D29) using three pharmacotherapeutic protocols: miltefosine monotherapy (Milteforan™, Virbac) (G1), miltefosine plus allopurinol (G2), and allopurinol monotherapy (G3). Forty-five dogs with CVL were assigned to one of three treatment groups. The dogs were evaluated for clinical signs, was well as haematological, biochemical, serological, and cytokine levels. Significant reduction in clinical scores was observed in all protocols, with no differences between groups. We did not observe a clinical cure in any of the dogs in the groups. Haematological and biochemical parameters showed slow recovery, with better results observed in G2. Anti-Leishmania antibody titre remained increased in all groups. The quantification of serum cytokines demonstrated a mixed Th1/Th2 profile in CVL. The IL-2 levels decreased in all groups after treatment. Evaluation of IFN-y and IL-10 did not show changes in the groups analysed, and it did not contribute to short term therapeutic monitoring. All therapeutic protocols promoted, to varying degrees, an improvement in the general condition (clinical signs, haematological, and biochemical levels) of the animals. Through clinical-pathological exams, we found that the combination of miltefosine plus allopurinol promoted better effects in the short-term, representing the best choice for the treatment of CVL, even when compared to the only therapeutic protocol allowed in Brazil, miltefosine monotherapy. Through the quantification of cytokines, IL-2 proved to be a potential therapeutic marker for the monitoring and follow-up of dogs with CVL.


Assuntos
Alopurinol/uso terapêutico , Antiprotozoários/uso terapêutico , Doenças do Cão/tratamento farmacológico , Leishmaniose Visceral/veterinária , Fosforilcolina/análogos & derivados , Animais , Citocinas/sangue , Doenças do Cão/parasitologia , Cães , Quimioterapia Combinada , Feminino , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/parasitologia , Masculino , Fosforilcolina/uso terapêutico
19.
Exp Parasitol ; 216: 107941, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32622940

RESUMO

Distinct antigens have been evaluated with diagnostic purpose for canine and human visceral leishmaniasis (VL), and variable sensitivity and specificity values have been obtained in the assays. In the present study, a Leishmania infantum hypothetical protein called LiHyG, which was identified in an immunoproteomics study in Leishmania infantum amastigote extracts by antibodies in VL dogs sera; was cloned, expressed, purified and evaluated as a recombinant protein (rLiHyG) for the diagnosis of canine and human disease. The recombinant amastigote-specific A2 protein (rA2) and a soluble L. infantum protein extract (SLA) were used as controls. For canine VL, the sensitivity values were of 100%, 57.29% and 48.57%, when rLiHyG, rA2 and SLA were used, respectively, while the specificity values were of 100%, 81.43% and 88.57%, respectively. In addition, AUC values were of 1.00, 0.72 and 0.65, when rLiHyG, rA2 and SLA were used, respectively, while accuracy was of 100%, 72.38% and 75.24%, respectively. For human VL, the sensitivity values were of 100%, 84.00% and 88.00%, when rLiHyG, rA2 and SLA were used, respectively, while the specificity values were of 100%, 58.75% and 73.75%, respectively. In addition, AUC values were of 1.00, 0.76 and 0.83, when rLiHyG, rA2 and SLA were used, respectively, while accuracy was of 100%, 64.8% and 66.6%, respectively. The prognostic role of rLiHyG in the human VL was also evaluated, by means of post-therapeutic serological follow-up with sera samples collected before and six months after treatment. Results showed that treated patients presented significant reductions in the anti-rLiHyG IgG, IgG1, and IgG2 antibody levels, with results being similar to those found in healthy subjects. Testing the rA2 protein and SLA as antigens, lower IgG, IgG1, and IgG2 levels were also found, although they were higher after treatment than those obtained for rLiHyG. In conclusion, results suggested that rLiHyG could be considered for future studies as a diagnostic and/or prognostic marker for canine and human VL.


Assuntos
Antígenos de Protozoários/isolamento & purificação , Doenças do Cão/parasitologia , Leishmania infantum/imunologia , Leishmaniose Visceral/diagnóstico , Adulto , Idoso , Sequência de Aminoácidos , Animais , Antígenos de Protozoários/genética , Medula Óssea/parasitologia , Biologia Computacional , DNA de Protozoário/química , DNA de Protozoário/isolamento & purificação , Doenças do Cão/diagnóstico , Cães , Ensaio de Imunoadsorção Enzimática , Epitopos de Linfócito B/química , Feminino , Humanos , Imunoglobulina G/sangue , Leishmania infantum/genética , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/veterinária , Masculino , Pessoa de Meia-Idade , Prognóstico , Proteínas de Protozoários/química , Sensibilidade e Especificidade , Alinhamento de Sequência , Testes Sorológicos , Baço/parasitologia , Adulto Jovem
20.
PLoS Negl Trop Dis ; 14(7): e0008429, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32687498

RESUMO

BACKGROUND: Few prospective data exist on incidence of post kala-azar dermal leishmaniasis (PKDL) and visceral leishmaniasis (VL) relapse after different treatment regimens. METHODOLOGY/PRINCIPAL FINDINGS: A Phase IV trial included 1761 VL patients treated between 2012-2014 with single dose AmBisome (SDA; N = 891), miltefosine-paromomycin (Milt-PM; n = 512), or AmBisome-miltefosine (AmB-Milt; n = 358). Follow-up for PKDL and VL relapse was scheduled for 6, 12 and 24 months after treatment, lasting until 2017. Patients with lesions consistent with PKDL were tested by rK39 rapid test, and if positive, underwent skin-snip sampling, smear microscopy and PCR. Probable PKDL was defined by consistent lesions and positive rK39; confirmed PKDL required additional positive microscopy or PCR. PKDL and relapse incidence density were calculated by VL treatment and risk factors evaluated in Cox proportional hazards models. Among 1,750 patients who completed treatment, 79 had relapse and 104 PKDL. Relapse incidence density was 1.58, 2.08 and 0.40 per 1000 person-months for SDA, AmB-Milt and Milt-PM, respectively. PKDL incidence density was 1.29, 1.45 and 2.65 per 1000 person-months for SDA, AmB-Milt and Milt-PM. In multivariable models, patients treated with Milt-PM had lower relapse but higher PKDL incidence than those treated with SDA; AmB-Milt rates were not significantly different from those for SDA. Children <12 years were at higher risk for both outcomes; females had a higher risk of PKDL but not relapse. CONCLUSIONS/SIGNIFICANCE: Active surveillance for PKDL and relapse, followed by timely treatment, is essential to sustain the achievements of VL elimination programs in the Indian sub-continent.


Assuntos
Anfotericina B/administração & dosagem , Antiprotozoários/administração & dosagem , Leishmaniose Cutânea/parasitologia , Leishmaniose Visceral/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Incidência , Índia/epidemiologia , Leishmaniose Cutânea/patologia , Leishmaniose Visceral/parasitologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Recidiva , Adulto Jovem
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