RESUMO
BackgroundSurveillance of human leishmaniasis in Europe is mostly limited to country-specific information from autochthonous infections in the southern part. As at the end of 2021, no integrated analysis has been performed for cases seen across centres in different European countries.AimTo provide a broad perspective on autochthonous and imported leishmaniasis cases in endemic and non-endemic countries in Europe.MethodsWe retrospectively collected records from cutaneous, mucosal and visceral leishmaniasis cases diagnosed in 15 centres between 2014 and 2019. Centres were located in 11 countries: Belgium, France, Germany, Italy, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Data on country of infection, reason for travelling, infecting species, age and sex were analysed.ResultsWe obtained diagnostic files from 1,142 cases, of which 76%, 21% and 3% had cutaneous, visceral, and mucosal disease, respectively. Of these, 68% were men, and 32% women, with the median age of 37 years (range: 0-90) at diagnosis. Visceral leishmaniasis was mainly acquired in Europe (88%; 167/190), while cutaneous leishmaniasis was primarily imported from outside Europe (77%; 575/749). Sixty-two percent of cutaneous leishmaniasis cases from outside Europe were from the Old World, and 38% from the New World. Geographic species distribution largely confirmed known epidemiology, with notable exceptions.ConclusionsOur study confirms previous reports regarding geographic origin, species, and traveller subgroups importing leishmaniasis into Europe. We demonstrate the importance of pooling species typing data from many centres, even from areas where the aetiology is presumably known, to monitor changing epidemiology.
Assuntos
Leishmaniose Cutânea , Leishmaniose Visceral , Leishmaniose , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Europa (Continente)/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Leishmaniose/diagnóstico , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/epidemiologia , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Viagem , Adulto JovemRESUMO
Leishmania protozoans are the causative agent of leishmaniasis, a neglected tropical disease consisting of three major clinical forms: visceral leishmaniasis (VL), cutaneous leishmaniasis, and mucocutaneous leishmaniasis. VL is caused by Leishmania donovani in East Africa and the Indian subcontinent and by Leishmania infantum in Europe, North Africa, and Latin America, and causes an estimated 60,000 deaths per year. Trypanothione reductase (TR) is considered to be one of the best targets to find new drugs against leishmaniasis. This enzyme is fundamental for parasite survival in the human host since it reduces trypanothione, a molecule used by the tryparedoxin/tryparedoxin peroxidase system of Leishmania to neutralize the hydrogen peroxide produced by host macrophages during infection. Recently, we solved the X-ray structure of TR in complex with the diaryl sulfide compound RDS 777 (6-(sec-butoxy)-2-((3-chlorophenyl)thio)pyrimidin-4-amine), which impairs the parasite defense against the reactive oxygen species by inhibiting TR with high efficiency. The compound binds to the catalytic site and engages in hydrogen bonds the residues more involved in the catalysis, namely Glu466', Cys57 and Cys52, thereby inhibiting the trypanothione binding. On the basis of the RDS 777-TR complex, we synthesized structurally related diaryl sulfide analogs as TR inhibitors able to compete for trypanothione binding to the enzyme and to kill the promastigote in the micromolar range. One of the most active among these compounds (RDS 562) was able to reduce the trypanothione concentration in cell of about 33% via TR inhibition. RDS 562 inhibits selectively Leishmania TR, while it does not inhibit the human homolog glutathione reductase.
Assuntos
Antiprotozoários/química , Antiprotozoários/farmacologia , Leishmania infantum/efeitos dos fármacos , Sulfetos/química , Sulfetos/farmacologia , Motivos de Aminoácidos , Domínio Catalítico , Glutationa/análogos & derivados , Glutationa/metabolismo , Humanos , Leishmania infantum/enzimologia , Leishmania infantum/metabolismo , Leishmaniose/tratamento farmacológico , Leishmaniose/parasitologia , Modelos Moleculares , NADH NADPH Oxirredutases/antagonistas & inibidores , NADH NADPH Oxirredutases/química , NADH NADPH Oxirredutases/genética , NADH NADPH Oxirredutases/metabolismo , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Espermidina/análogos & derivados , Espermidina/metabolismoRESUMO
The study presented here aimed at identifying a new class of compounds acting against Leishmania parasites, the causative agent of Leishmaniasis. For this purpose, the thioether derivatives of our in-house library have been evaluated in whole-cell screening assays in order to determine their in vitro activity against Leishmania protozoan. Among them, promising results have been achieved with compound RDS 777 (6-(sec-butoxy)-2-((3-chlorophenyl)thio)pyrimidin-4-amine) (IC50 = 29.43 µM), which is able to impair the mechanism of the parasite defence against the reactive oxygen species by inhibiting the trypanothione reductase (TR) with high efficiency (Ki 0.25 ± 0.18 µM). The X-ray structure of L. infantum TR in complex with RDS 777 disclosed the mechanism of action of this compound that binds to the catalytic site and engages in hydrogen bonds the residues more involved in the catalysis, namely Glu466', Cys57 and Cys52, thereby inhibiting the trypanothione binding and avoiding its reduction.
Assuntos
Leishmania infantum/enzimologia , NADH NADPH Oxirredutases/antagonistas & inibidores , Sulfetos/farmacologia , Cristalografia por Raios X , Modelos Moleculares , NADH NADPH Oxirredutases/químicaRESUMO
Leishmaniasis is endemic in southern Europe, and in other European countries cases are diagnosed in travellers who have visited affected areas both within the continent and beyond. Prompt and accurate diagnosis poses a challenge in clinical practice in Europe. Different methods exist for identification of the infecting Leishmania species. Sixteen clinical laboratories in 10 European countries, plus Israel and Turkey, conducted a study to assess their genotyping performance. DNA from 21 promastigote cultures of 13 species was analysed blindly by the routinely used typing method. Five different molecular targets were used, which were analysed with PCR-based methods. Different levels of identification were achieved, and either the Leishmania subgenus, species complex, or actual species were reported. The overall error rate of strains placed in the wrong complex or species was 8.5%. Various reasons for incorrect typing were identified. The study shows there is considerable room for improvement and standardisation of Leishmania typing. The use of well validated standard operating procedures is recommended, covering testing, interpretation, and reporting guidelines. Application of the internal transcribed spacer 1 of the rDNA array should be restricted to Old World samples, while the heat-shock protein 70 gene and the mini-exon can be applied globally.
Assuntos
Proteínas de Choque Térmico HSP70/genética , Leishmania/genética , Leishmaniose/diagnóstico , Reação em Cadeia da Polimerase/métodos , DNA de Cinetoplasto , DNA de Protozoário/genética , DNA Ribossômico , Europa (Continente) , Genótipo , Humanos , Israel , Laboratórios , Leishmania/isolamento & purificação , Polimorfismo de Fragmento de Restrição , Sensibilidade e Especificidade , TurquiaRESUMO
BACKGROUND: Visceral leishmaniasis (VL) is a severe disease caused by Leishmania infantum in the Mediterranean basin, and is associated with considerable morbidity and mortality. Infantile VL may begin suddenly, with high fever and vomiting, or insidiously, with irregular daily fever, anorexia, and marked splenomegaly. Delays in diagnosis of VL are common, highlighting the need for increased awareness of clinicians for VL in endemic European countries. CASE PRESENTATION: We report 4 cases of young children in northern Italy presenting with persistent fever of unknown origin and diagnosed with VL by serological and molecular methods. At the time of diagnosis, these patients showed an unusual echographic pattern characterized by multiple iso-hypoechoic nodules associated with splenomegaly. CONCLUSION: We suggest that detection of spleen nodules represents a signature of VL in infants, thus helping to diagnose systemic Leishmania infantum infection in children.
Assuntos
Leishmania infantum , Leishmaniose Visceral/diagnóstico , Baço/patologia , Criança , Diagnóstico Diferencial , Feminino , Febre de Causa Desconhecida/etiologia , Humanos , Lactente , Itália , Leishmaniose Visceral/complicações , Masculino , Exame FísicoRESUMO
Trypanothione reductase (TR) is a suitable target for drug discovery approaches against leishmaniasis, although the identification of potent inhibitors is still challenging. Herein, we harnessed a fragment-based drug discovery (FBDD) strategy to develop new TR inhibitors. Previous crystallographic screening identified fragments 1-3, which provided ideal starting points for a medicinal chemistry campaign. In silico investigations revealed critical hotspots in the TR binding site, guiding our structure- and ligand-based structure-actvity relationship (SAR) exploration that yielded fragment-derived compounds 4-14. A trend of improvement in Leishmania infantum TR inhibition was detected along the optimization and confirmed by the crystal structures of 9, 10, and 14 in complex with Trypanosoma brucei TR. Compound 10 showed the best TR inhibitory profile (Ki = 0.2 µM), whereas 9 was the best one in terms of in vitro and ex vivo activity. Although further fine-tuning is needed to improve selectivity, we demonstrated the potentiality of FBDD on a classic but difficult target for leishmaniasis.
Assuntos
Inibidores Enzimáticos , Leishmaniose , Humanos , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Inibidores Enzimáticos/química , NADH NADPH Oxirredutases/metabolismo , Leishmaniose/tratamento farmacológico , Sítios de LigaçãoRESUMO
The objective of the present study was to evaluate the diagnostic performance of a noninvasive assay, conjunctival swab (CS) nested-PCR (n-PCR), for diagnosing canine leishmaniasis (CanL) in different stages of infection in comparison to the performance of the indirect immunofluorescence antibody test (IFAT), lymph node microscopy, and buffy coat n-PCR. To this end, we performed a cross-sectional survey among 253 nonselected dogs in areas of endemicity in central Italy. We also performed a longitudinal study of CS n-PCR among 20 sick dogs undergoing antileishmanial treatment. In the first study, among the 72 animals that were positive by at least one test (28.45%), CS n-PCR showed the best relative performance (76.38%), with a high concordance in comparison to standard IFAT serology (κ = 0.75). The highest positivity rates using CS n-PCR were found in asymptomatic infected dogs (84.2%) and sick dogs (77.8%); however, the sensitivity of the assay was not associated with the presence of clinical signs. In the follow-up study on treated sick dogs, CS n-PCR was the most sensitive assay, with promising prognostic value for relapses. The univariate analysis of risk factors for CanL based on CS n-PCR findings showed a significant correlation with age (P = 0.012), breed size (P = 0.026), habitat (P = 4.9 × 10(-4)), and previous therapy (P = 0.014). Overall, the results indicated that CS n-PCR was the most sensitive assay of the less invasive diagnostic methods and could represent a good option for the early and simple diagnosis of CanL infection in asymptomatic animals and for monitoring relapses in drug-treated dogs.
Assuntos
Túnica Conjuntiva/parasitologia , Doenças do Cão/diagnóstico , Doenças do Cão/parasitologia , Leishmania infantum/isolamento & purificação , Leishmaniose/veterinária , Parasitologia/métodos , Reação em Cadeia da Polimerase/métodos , Animais , Buffy Coat/parasitologia , Estudos Transversais , Cães , Feminino , Técnica Indireta de Fluorescência para Anticorpo/métodos , Itália , Leishmaniose/diagnóstico , Leishmaniose/parasitologia , Linfonodos/parasitologia , Masculino , Microscopia/métodos , Técnicas de Diagnóstico Molecular/métodos , Sensibilidade e Especificidade , Medicina Veterinária/métodosRESUMO
Auranofin is a gold(I)-containing drug in clinical use as an antiarthritic agent. Recent studies showed that auranofin manifests interesting antiparasitic actions very likely arising from inhibition of parasitic enzymes involved in the control of the redox metabolism. Trypanothione reductase is a key enzyme of Leishmania infantum polyamine-dependent redox metabolism, and a validated target for antileishmanial drugs. As trypanothione reductase contains a dithiol motif at its active site and gold(I) compounds are known to be highly thiophilic, we explored whether auranofin might behave as an effective enzyme inhibitor and as a potential antileishmanial agent. Notably, enzymatic assays revealed that auranofin causes indeed a pronounced enzyme inhibition. To gain a deeper insight into the molecular basis of enzyme inhibition, crystals of the auranofin-bound enzyme, in the presence of NADPH, were prepared, and the X-ray crystal structure of the auranofin-trypanothione reductase-NADPH complex was solved at 3.5 Å resolution. In spite of the rather low resolution, these data were of sufficient quality as to identify the presence of the gold center and of the thiosugar of auranofin, and to locate them within the overall protein structure. Gold binds to the two active site cysteine residues of TR, i.e. Cys52 and Cys57, while the thiosugar moiety of auranofin binds to the trypanothione binding site; thus auranofin appears to inhibit TR through a dual mechanism. Auranofin kills the promastigote stage of L. infantum at micromolar concentration; these findings will contribute to the design of new drugs against leishmaniasis.
Assuntos
Antiprotozoários/farmacologia , Auranofina/farmacologia , Poliaminas Biogênicas/metabolismo , Ouro/química , Leishmania infantum/metabolismo , NADH NADPH Oxirredutases/metabolismo , Animais , Antiprotozoários/química , Auranofina/química , Leishmania infantum/enzimologia , Modelos Moleculares , NADH NADPH Oxirredutases/antagonistas & inibidores , NADH NADPH Oxirredutases/química , Difração de Raios XRESUMO
Epidemiological studies on the distribution of leishmaniasis caused by Leishmania infantum Nicolle, 1908 (Kinetoplastida: Trypanosomatidae) have been based principally on serological surveys of the canine reservoir. This methodology is useful due to the facility of sampling, the rapidity in obtaining results, its consistency and because it allows the detection of heterogeneous foci of canine leishmaniasis (CanL) even in small areas. Other investigations have analysed Leishmania parasitism in sandflies (Diptera: Psychodidae: Phlebotominae) by using classical dissection techniques. These techniques allow the vector species to be incriminated in different foci, although they suffer from being very time consuming. Lately, studies in this field are increasingly using molecular techniques, which are faster and easier to perform. In the present work, we applied a nested-PCR in a study of natural infection of sandflies by Leishmania in three isolated farms where serological data on canine leishmaniasis of local dogs were also obtained. The analysis allowed the detection of 38.7% of females with positive nested-PCR (78%, 18% and 0%, respectively, in the different isolated farms). The positive Leishmania DNA samples were genotyped and identified as L. infantum. The results of this work provide new data for the vectorial capacity of Phlebotomus ariasi in a Pyrenean area, which can be considered at risk of becoming a new focus of CanL. The females with positive nested-PCR displayed blood in the midgut at different degrees of digestion, and/or were gravid. According to the multivariate logistic regression analysis, the risk of nested-PCR-positivity increased significantly with the degree of blood digestion (OR = 1.3; P value = 0.025). The Phlebotomus species and the presence of eggs were not statistically associated with nested-PCR positivity (P value of >0.05). The correlation of positive nested-PCR results with the presence of seropositive dogs in the farm confirms the utility of this technique in the study of the distribution and intensity of leishmaniasis foci. Also, the importance of sandfly blood-meal digestion for epidemiological surveys of leishmaniasis foci has been demonstrated.
Assuntos
Doenças do Cão/parasitologia , Insetos Vetores/fisiologia , Leishmania infantum/fisiologia , Leishmaniose Visceral/veterinária , Psychodidae/fisiologia , Animais , DNA de Protozoário/isolamento & purificação , DNA Ribossômico/genética , DNA Ribossômico/isolamento & purificação , Digestão , Doenças do Cão/epidemiologia , Cães , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , Polimorfismo de Fragmento de Restrição , Testes Sorológicos/veterinária , Espanha/epidemiologiaRESUMO
Leishmania spp. are responsible for up to 1 million new cases each year. The current therapeutic arsenal against Leishmania is largely inadequate, and there is an urgent need for better drugs. Trypanothione reductase (TR) represents a druggable target since it is essential for the parasite and not shared by the human host. Here, we report the optimization of a novel class of potent and selective LiTR inhibitors realized through a concerted effort involving X-ray crystallography, synthesis, structure-activity relationship (SAR) investigation, molecular modeling, and in vitro phenotypic assays. 5-Nitrothiophene-2-carboxamides 3, 6e, and 8 were among the most potent and selective TR inhibitors identified in this study. 6e and 8 displayed leishmanicidal activity in the low micromolar range coupled to SI > 50. Our studies could pave the way for the use of TR inhibitors not only against leishmaniasis but also against other trypanosomatidae due to the structural similarity of TR enzymes.
Assuntos
Leishmania , Leishmaniose , Descoberta de Drogas , Humanos , Leishmaniose/tratamento farmacológico , NADH NADPH OxirredutasesRESUMO
INTRODUCTION: Mucocutaneous leishmaniasis (MCL) is a complication of tegumentary leishmaniasis, causing potentially life-threatening lesions in the ear, nose, and throat (ENT) region, and most commonly due to Leishmania (Viannia) braziliensis. We report a case of relapsing MCL in an Italian traveler returning from Argentina. CASE DESCRIPTION: A 65-year-old Italian male patient with chronic kidney disease, arterial hypertension, prostatic hypertrophy, and type-2 diabetes mellitus was referred for severe relapsing MCL acquired in Argentina. ENT examination showed severe diffuse pharyngolaryngeal edema and erythema, partially obstructing the airways. A nasopharyngeal biopsy revealed a lymphoplasmacytic inflammation and presence of Leishmania amastigotes, subsequently identified as L. (V.) braziliensis by hsp70 PCR-RFLP analysis and sequencing. Despite receiving four courses of liposomal amphotericine B (L-AmB) and two courses of miltefosine over a 2-year period, the patient presented recurrence of symptoms a few months after the end of each course. After the patient was referred to us, a combined treatment was started with intravenous pentamidine 4 mg/kg on alternate days for 10 doses, followed by one dose per week for an additional seven doses, intralesional meglumine antimoniate on the nasal lesion once per week for six doses, oral azoles for three months, and aerosolized L-AmB on alternate days for three months. The treatment led to regression of mucosal lesions and respiratory symptoms. Renal function temporarily worsened, and the addition of insulin was required to maintain glycemic compensation after pentamidine discontinuation. CONCLUSIONS: This case highlights the difficulties in managing a life-threatening refractory case of MCL in an Italian traveler with multiple comorbidities. Even though parenteral antimonial derivatives are traditionally considered the treatment of choice for MCL, they are relatively contraindicated in cases of chronic kidney disease.The required dose adjustment in cases of impaired renal function is unknown, therefore the use of alternative drugs is recommended. This case was resolved with combination treatment, including aerosolized L-AmB, which had never been used before for MCL.
Assuntos
Anfotericina B/administração & dosagem , Antiprotozoários/administração & dosagem , Azóis/administração & dosagem , Leishmaniose Mucocutânea/tratamento farmacológico , Antimoniato de Meglumina/administração & dosagem , Pentamidina/administração & dosagem , Administração Intravenosa , Idoso , Argentina , Quimioterapia Combinada , Humanos , Leishmania braziliensis/efeitos dos fármacos , Leishmania braziliensis/fisiologia , Leishmaniose Mucocutânea/parasitologia , Masculino , RecidivaRESUMO
BACKGROUND: Cutaneous leishmaniasis (CL) is widespread in Yemen, but not fully documented. OBJECTIVE: To study the clinicoepidemiologic profile of CL in the northwestern region of Yemen Republic and to identify the responsible Leishmania species by molecular methods. METHODS: All 265 CL cases (176 males and 89 females) were subjected to detailed analysis. Diagnosis was based on clinical features, positive slit skin smear, and histopathologic findings in some cases. In 198 cases, positive smears were examined at the Leishmania Reference Centre of Istituto Superiore di Sanità, Rome (Italy), by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis for Leishmania typing. RESULTS: All patients were Yemeni nationals, originated from 10 governorates of northwestern Yemen. Most of the patients had a single noduloulcerative lesion on the face suggestive of "dry"-type CL. Slit skin smear was positive in 255 cases (96.23%). Leishmania sp PCR was positive in all 198 cases examined; the RFLP analysis was positive in 155 samples with the following identification results: L. tropica in 133 cases (85.80%), L. infantum in 17 (10.97%), and L. donovani in 5 (3.23%). LIMITATIONS: This was a prospective study of CL cases at one center only; hence, the full extent of the disease in the entire region cannot be predicted. CONCLUSION: CL appears to be endemic in northwestern region of Yemen, clinically presenting as 'dry' type, caused mainly by L. tropica (85.8% of cases) and occasionally by L. infantum (10.97%) and L. donovani (3.23%). There is a need for a multicenter study to evaluate the extent of the disease and diffusion of each Leishmania responsible species.
Assuntos
Leishmania/genética , Leishmania/isolamento & purificação , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/microbiologia , Polimorfismo de Fragmento de Restrição , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Feminino , Sistemas de Informação Geográfica , Humanos , Lactente , Leishmania donovani/genética , Leishmania donovani/isolamento & purificação , Leishmania infantum/genética , Leishmania infantum/isolamento & purificação , Leishmania tropica/genética , Leishmania tropica/isolamento & purificação , Leishmaniose Cutânea/patologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Iêmen/epidemiologia , Adulto JovemRESUMO
Imported cases of anthroponotic cutaneous leishmaniasis due to Leishmania tropica are increasingly documented in Europe. We investigated the ability of Phlebotomus perniciosus, a competent vector of Leishmania infantum widespread in southwestern Europe, to support the growth and transmissibility of an Asian strain of L. tropica recently isolated from a refugee. Parasite growth behavior was investigated in laboratory-reared sand flies fed artificially with promastigotes as well as in sand flies infected after biting on footpad lesions induced in hamsters by promastigote inoculation. The evolution of infection was checked by gut microscopy and quantitative real-time PCR, and it was found to be similar between promastigote- and amastigote-initiated infections. In 80% of infected sand flies, despite survival and flourishing growth of promastigotes after blood digestion and defecation, either the parasites died, or failed to migrate to the foregut and/or to mature into infective forms. However, in the remaining 20% L. tropica developed into abundant metacyclic promastigotes. The quantitative real-time PCR assay detected variable loads of gut promastigotes irrespective of morphological evidence of viability or progressive/final death. Parasite transmissibility was investigated by exposing naive hamsters to P. perniciosus previously infected on chronic lesions induced in hamsters which survived to take a second blood meal. Two months post exposure, lesions developed in skin sites bitten by sand flies confirmed to harbor metacyclic promastigotes; in the following months, the presence of viable and transmissible L. tropica parasites in lesions was demonstrated by xenodiagnosis assays. Our findings support the hypothesis that, in particular epidemiological situations, P. perniciosus may play the role of an occasional L. tropica vector.
Assuntos
Insetos Vetores/parasitologia , Leishmania tropica/fisiologia , Leishmaniose Cutânea/transmissão , Phlebotomus/parasitologia , Animais , Ásia , Cricetinae , Europa (Continente) , Feminino , Humanos , Insetos Vetores/classificação , Leishmania tropica/genética , Leishmania tropica/crescimento & desenvolvimento , Leishmania tropica/isolamento & purificação , Mesocricetus , Phlebotomus/classificação , Reação em Cadeia da Polimerase em Tempo Real , RefugiadosRESUMO
Eighty years after the last published record of human leishmaniasis from Dagestan, Russian Federation, we report two recent cases which were most probably acquired locally: one case of visceral leishmaniasis in a 2-year old child, and one cutaneous leishmaniasis case in a 39-year-old man co-infected with HIV, both resident in Dagestan.
Assuntos
Leishmaniose Cutânea/diagnóstico , Leishmaniose Visceral/diagnóstico , Adulto , Criança , Pré-Escolar , Coinfecção , Daguestão , Feminino , Infecções por HIV/complicações , Humanos , Leishmaniose Cutânea/complicações , MasculinoRESUMO
BACKGROUND: The epidemiology of feline vector-borne pathogens (FeVBPs) has been less investigated in cats than in dogs. The present study assessed the prevalence of Rickettsia spp., Babesia spp., Cytauxzoon spp. and Leishmania infantum infections in cat populations living in central Italy, by molecular and serological tools. RESULTS: A total of 286 healthy cats were randomly selected from catteries and colonies in central Italy. Peripheral blood and conjunctival swab (CS) samples were collected during surgical procedures for regional neutering projects. Sera were analysed by IFAT to detect anti-Rickettsia felis, R. conorii, Babesia microti and Leishmania IgG antibodies using commercial and home-made antigens. DNA extracted from buffy coats (BCs) was tested for Rickettsia spp., and Piroplasmida species, including Cytauxzoon spp. and Babesia spp. by PCR. Buffy coats and CS samples were assayed by a nested (n)-PCR for Leishmania spp. Sixty-two cats (21.67%) were seropositive to at least one of the tested pathogens. The serological assay revealed 23 (8.04%) and 18 (6.29%) positive cats for R. felis and R. conorii, respectively, with low titers (1/64-1/128). No antibodies against B. microti were detected. Neither Rickettsia nor Piroplasmida DNA were amplified using the specific PCR assays. Thirty-one cats (10.83%) tested positive to anti-Leishmania IgG, with titers ranging from 1:40 to 1:160 and 45 animals (15.73%) tested positive to Leishmania CS n-PCR, whereas none of the animals tested positive to BC n-PCR. Considering the results obtained by IFAT and CS n-PCR, a moderate agreement between the two tests was detected (κ = 0.27). CONCLUSIONS: The results of the serological and molecular surveys showed a moderate exposure to Leishmania in the investigated cats and highlighted the limited molecular diagnostic value of BC versus CS samples for this pathogen. Conversely no evidence supported the circulation of Cytauxzoon spp. in domestic cats, in contrast with previous detections in European wild cats in the same areas monitored. The low positive titres for R. felis in association with no DNA BC amplification prevent speculation on the exposure of feline populations to this FeVBP due to the cross-reactivity existing within spotted fever group rickettsiosis (SFGR).
Assuntos
Apicomplexa/isolamento & purificação , Babesia/isolamento & purificação , Doenças do Gato/microbiologia , Doenças do Gato/parasitologia , Doenças Transmissíveis Emergentes/veterinária , Leishmania infantum/isolamento & purificação , Infecções Protozoárias em Animais/parasitologia , Infecções por Rickettsia/veterinária , Rickettsia/isolamento & purificação , Animais , Apicomplexa/classificação , Apicomplexa/genética , Babesia/classificação , Babesia/genética , Doenças do Gato/epidemiologia , Gatos , Doenças Transmissíveis Emergentes/microbiologia , Doenças Transmissíveis Emergentes/parasitologia , Estudos Transversais , Feminino , Itália/epidemiologia , Leishmania infantum/classificação , Leishmania infantum/genética , Masculino , Rickettsia/classificação , Rickettsia/genética , Infecções por Rickettsia/microbiologiaRESUMO
The management of mucosal leishmaniasis in immunocompromised patients is not standardized and limited data are available on the use of miltefosine for treatment and secondary prophylaxis. We describe a case of mucosal leishmaniasis in an HIV-coinfected patient treated with miltefosine due to a severe allergic reaction to liposomal amphotericin B.
Assuntos
Leishmaniose Mucocutânea/tratamento farmacológico , Fosforilcolina/análogos & derivados , Coinfecção , Infecções por HIV/complicações , Humanos , Leishmaniose Mucocutânea/complicações , Masculino , Pessoa de Meia-Idade , Fosforilcolina/uso terapêutico , Fatores de TempoRESUMO
Trypanothione reductase (TR) is considered to be one of the best targets to find new drugs against Leishmaniasis. This enzyme is fundamental for parasite survival in the host since it reduces trypanothione, a molecule used by the tryparedoxin/tryparedoxin peroxidase system of Leishmania to neutralize hydrogen peroxide produced by host macrophages during infection. In order to identify new lead compounds against Leishmania we developed and validated a new luminescence-based high-throughput screening (HTS) assay that allowed us to screen a library of 120,000 compounds. We identified a novel chemical class of TR inhibitors, able to kill parasites with an IC50 in the low micromolar range. The X-ray crystal structure of TR in complex with a compound from this class (compound 3) allowed the identification of its binding site in a pocket at the entrance of the NADPH binding site. Since the binding site of compound 3 identified by the X-ray structure is unique, and is not present in human homologs such as glutathione reductase (hGR), it represents a new target for drug discovery efforts.
Assuntos
Antiprotozoários/química , Inibidores Enzimáticos/química , Leishmania/enzimologia , NADH NADPH Oxirredutases/antagonistas & inibidores , Proteínas de Protozoários/antagonistas & inibidores , Antiprotozoários/metabolismo , Antiprotozoários/farmacologia , Sítios de Ligação , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Ensaios de Triagem em Larga Escala , Humanos , Leishmania/efeitos dos fármacos , Leishmania/genética , Leishmaniose/parasitologia , Modelos Moleculares , NADH NADPH Oxirredutases/química , NADH NADPH Oxirredutases/genética , NADH NADPH Oxirredutases/metabolismo , NADP/metabolismo , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismoRESUMO
Despite the recent reports of feline leishmaniosis from Southern Europe, cats are still regarded as unusual Leishmania hosts. A cat found chronically infected with Leishmania was submitted to xenodiagnosis. After being sedated, the animal was exposed to the bite of 100 laboratory-reared Phlebotomus perniciosus in a fine net cage for 90 min. Four out of 19 blood-fed sandflies (21%) showed motile promastigotes at the dissection. Parasites cultured from cat's lymph node and an infected fly were identical at PCR-RFLP genotyping and identified as Leishmania infantum MON-1, the main zymodeme responsible for human and canine leishmaniosis in Southern Europe. This is the first evidence of transmissibility of feline parasites to a proven vector, suggesting that cats may represent an additional domestic reservoir for L. infantum.
Assuntos
Doenças do Gato/parasitologia , Doenças do Gato/transmissão , Leishmania infantum/fisiologia , Leishmaniose Visceral/veterinária , Psychodidae/parasitologia , Animais , Mordeduras e Picadas/parasitologia , Mordeduras e Picadas/veterinária , Gatos , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/transmissãoRESUMO
The incidence of visceral leishmaniasis (VL) in Albania is higher than in other countries of southern Europe, however the role of local sand fly species in the transmission of Leishmania infantum was not addressed conclusively. In 2006, a country-wide collection of sand flies performed in 14 sites selected based on recent occurrence of VL cases showed that Phlebotomus neglectus was by far the most prevalent species (95.6%). Furthermore, 15% of pools made from 422 P. neglectus females tested positive for Leishmania sp. genomic DNA. In the same year, Culicoides trapping was performed for bluetongue disease surveillance in 91 sites of southern Albania, targeting livestock farms regardless recent occurrence of VL in the surveyed areas. In 35 sites where sand flies were collected along with midges, Phlebotomus perfiliewi was the most prevalent among the Phlebotomus species identified, however search for leishmanial DNA in females of this species was unsuccessful. In 2011, sand flies were trapped in 4 sites of north Albania characterized by high VL incidence, and females were dissected to search for Leishmania infections. Both P. neglectus and P. tobbi were collected at high densities. Two positive specimens were detected from a sample of 64 P. neglectus trapped in one site (3.1%). Parasites were successfully cultured from one specimen and characterized as belonging to Leishmania infantum zymodeme MON-1, the only zymodeme so far identified as the agent of human and canine leishmaniasis in the country. Altogether our studies indicate that P. neglectus is the main leishmaniasis vector in Albania.
Assuntos
Insetos Vetores/parasitologia , Leishmania infantum/fisiologia , Psychodidae/parasitologia , Albânia/epidemiologia , Animais , DNA de Protozoário/metabolismo , Cães , Feminino , Humanos , Incidência , Leishmania infantum/genética , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/veterinária , Masculino , Reação em Cadeia da PolimeraseRESUMO
BACKGROUND: Leishmaniasis in Serbia was an endemic disease, and is considered to be eradicated for more than 40 years. In the past decade sporadic cases of canine leishmaniasis started to emerge for the first time in Vojvodina Province (previously non-endemic region of Serbia). Reports of introduced, and later on autochthonous cases of leishmaniasis alerted the possibility of disease emergence. The aim of this study was to bridge more than a half a century wide gap in entomological surveillance of sand fly vectors in Vojvodina, as well as to verify the presence of the vector species that could support Leishmania spp. circulation. RESULTS: During the period 2013-2015, a total of 136 sand flies were collected from 48 of 80 surveyed locations. Four sand fly species of the genus Phlebotomus were detected: P. papatasi, P. perfiliewi, P. mascittii and P. neglectus. Detection of P. mascittii represents the first record of this species for the sand fly fauna in Vojvodina and in Serbia. All female specimens (n = 80) were tested for Leishmania spp. DNA, and three blood-fed P. papatasi specimens were positive (4%). One positive DNA sample was successfully amplified by ITS1 nPCR. The RFLP analysis of the resulting 350 bp fragment showed a typical pattern of L. infantum, and the ITS1 partial sequence blasted in GenBank confirmed 100% identity with L. infantum and L. donovani complex sequences. This result represents the first record of both Leishmania spp. and L. infantum DNA from sand flies in Vojvodina, and in Serbia. CONCLUSIONS: Presence of autochthonous canine leishmaniasis cases, records of Phlebotomus (Larroussius) species proven vectors of L. infantum (P. perfiliewi and P. neglectus) and detection of L. infantum DNA from wild caught (non-competent) vectors, prove that L. infantum is present in Vojvodina and indicates a probable circulation in the region.