RESUMEN

There are few reports of Trypanosoma in snakes, as well as little information about its pathogenicity in these animals. Thus, the present study aimed to characterize Trypanosoma found in Boa constrictor snakes, to verify the influence of the parasitism on hematological and clinical biochemistry parameters, and to perform a phylogenetic study of the isolates. Blood samples from sixty-one boas were analyzed for the presence of trypanosomatids and by hematological and clinical biochemistry assays. The flagellates that were found in this analysis were used for cell culture, morphometry, and molecular analysis. Later, molecular typing phylogenetic studies were performed. Nine positive animals (14.75%) were identified by microscopy analysis. The hematological results showed that parasitized animals presented significantly lower levels of packed cell volume, hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin. In the leukogram, eosinophils and heterophils counts were higher in parasitized animals. Considering the molecular analyses, the isolates presented a higher identity of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the 18S small subunit ribosomal RNA (SSU rRNA) gene fragments with Trypanosoma serpentis. The phylogenetic tree, using the GAPDH, clustered all isolates with T. serpentis and Trypanosoma cascavelli. This is the first description of T. serpentis parasitizing boas and of the clinical changes caused by trypanosomatid infection in snakes.

Asunto(s)

Boidae , Trypanosoma , Animales , Boidae/genética , Filogenia , ADN Ribosómico/genética , ARN Ribosómico 18S/genética , Serpientes , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , ADN Protozoario

RESUMEN

We used spatial analysis tools to examine the epidemiological situation and spatial distribution of American tegumentary leishmaniasis in the municipality of Caratinga between 2016 and 2021. In addition, potential sandfly vectors were captured. All information used in this study was retrieved from public health archives and confirmed in the state health services databases. All cases were analyzed using Geographic Information Systems software. In addition, sandfly collections and molecular detection of Leishmania were carried out in areas with the highest number of cases. During the analyzed period, American tegumentary leishmaniasis (ATL) cases increased and remained high in the last years. The hotspots included urban areas of Caratinga city and the districts of Patrocínio of Caratinga and Sapucaia. The species Nyssomyia whitmani, Nyssomyia intermedia, and Migonemyia migonei were the most abundant species and the ITS1-polymerase chain reaction technique detected Leishmania DNA in these species. On the basis of our analyses, the urbanization of ATL in Caratinga has taken place in recent years. Because of the increase in the number of human cases and the presence of vectors, it is recommended that health authorities focus on control measures in hotspots.

Asunto(s)

Leishmania , Leishmaniasis Cutánea , Phlebotomus , Psychodidae , Animales , Humanos , Brasil/epidemiología , Insectos Vectores , Leishmaniasis Cutánea/epidemiología , Leishmania/genética

RESUMEN

Lipophosphoglycan (LPG), the major Leishmania glycoconjugate, induces pro-inflammatory/immunosuppressive innate immune responses. Here, we evaluated functional/biochemical LPG properties from six Leishmania amazonensis strains from different hosts/clinical forms. LPGs from three strains (GV02, BA276, and LV79) had higher pro-inflammatory profiles for most of the mediators, including tumor necrosis factor alpha and interleukin 6. For this reason, glycoconjugates from all strains were biochemically characterized and had polymorphisms in their repeat units. They consisted of three types: type I, repeat units devoid of side chains; type II, containing galactosylated side chains; and type III, containing glucosylated side chains. No relationship was observed between LPG type and the pro-inflammatory properties. Finally, to evaluate the susceptibility against antileishmanial agents, two strains with high (GV02, BA276) and one with low (BA336) pro-inflammatory activity were selected for chemotherapeutic tests in THP-1 cells. All analyzed strains were susceptible to amphotericin B (AmB) but displayed various responses against miltefosine (MIL) and glucantime (GLU). The GV02 strain (canine visceral leishmaniasis) had the highest IC50 for MIL (3.34 µM), whereas diffuse leishmaniasis strains (BA276 and BA336) had a higher IC50 for GLU (6.87-12.19 mM). The highest IC50 against MIL shown by the GV02 strain has an impact on clinical management. Miltefosine is the only drug approved for dog treatment in Brazil. Further studies into drug susceptibility of L. amazonensis strains are warranted, especially in areas where dog infection by this species overlaps with those caused by Leishmania infantum.

Asunto(s)

Anfotericina B , Leishmania , Anfotericina B/farmacología , Animales , Perros , Glicoesfingolípidos , Interleucina-6 , Leishmania/genética , Antimoniato de Meglumina/farmacología , Ratones , Ratones Endogámicos BALB C , Fosforilcolina/análogos & derivados , Factor de Necrosis Tumoral alfa

RESUMEN

Leishmania major is the causative agent of cutaneous leishmaniasis. It is one of the most studied Leishmania species not only during vector interaction but also in the vertebrate host. Lipophosphoglycan (LPG) is the Leishmania multifunctional virulence factor during host-parasite interaction, whose polymorphisms are involved in the immunopathology of leishmaniasis. Although natural hybrids occur in nature, hybridization of L. major strains in the laboratory was successfully demonstrated. However, LPG expression in the hybrids remains unknown. LPGs from parental (Friedlin, Fn and Seidman, Sd) and hybrids (FnSd3, FnSd4A, FnSd4B, and FnSd6F) were extracted, purified, and their repeat units analyzed by immunoblotting and fluorophore-assisted carbohydrate electrophoresis. Parental strains have distinct profiles in LPG expression, and a mixed profile was observed for all hybrids. Variable levels of NO production by macrophages were detected after LPG exposure (parental and hybrids) and were strain specific.

Asunto(s)

Leishmania major , Leishmaniasis Cutánea , Glicoesfingolípidos/metabolismo , Humanos , Leishmania major/genética , Leishmania major/metabolismo , Leishmaniasis Cutánea/parasitología , Macrófagos/metabolismo

RESUMEN

BACKGROUND: The municipality of Caratinga is an important endemic area for American Tegumentary Leishmaniasis (ATL) and no epidemiological studies were performed during the past two decades. Here, we analyzed the epidemiological situation and the geographical distribution of ATL cases in the municipality of Caratinga from 2007 to 2018 using geographic information systems (GIS). Also, we evaluated the impact of several demographic parameters in ATL distribution and the sand flies incriminated in its transmission. METHODS: All demographic information (gender, age, educational level, clinical form, diagnostic criteria and case evolution) used in this study was retrieved from the public health archives and confirmed in the State Health Services databases. All cases were analyzed using GIS software based on ATL distribution. Also, non-systematic sand fly collections and molecular detection of Leishmania were performed in the hotspots. RESULTS AND CONCLUSIONS: During the period, ATL cases continued and increased especially in the past years (2016-2018). Hotspots included urban Caratinga areas and the districts of Patrocínio de Caratinga and Sapucaia. The species Nyssomyia whitmani, Nyssomyia intermedia, Migonemyia migonei and Evandromyia cortelezzii complex were captured. However, ITS1-PCR did not detect Leishmania DNA in those insects. Based on our analyses, urbanization of ATL in Caratinga has occurred in the past years. Due to the increase in the number of cases and vectors presence, it is recommended that health authorities focus on control measures in the most affected areas (Patrocínio of Caratinga and Sapucaia districts and urban Caratinga).

Asunto(s)

Leishmania/aislamiento & purificación , Leishmaniasis Cutánea/epidemiología , Psychodidae/clasificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Brasil/epidemiología , Niño , Preescolar , Femenino , Estudios de Seguimiento , Sistemas de Información Geográfica , Humanos , Lactante , Leishmania/genética , Leishmaniasis Cutánea/transmisión , Masculino , Persona de Mediana Edad , Áreas de Pobreza , Psychodidae/parasitología

RESUMEN

The escape kinetics from the anterior midgut (AM) of Trypanosoma cruzi during the initial steps of infection was assessed in Triatoma infestans, as well as its ability to survive migration in the digestive tract of the vector. All the four strains evaluated survived and reached variable parasite densities. After 49-50 days, YuYu [discrete typing units (DTU) I] strain reached the highest parasite numbers in the rectum followed by Bug (DTU V), CL-Brener (DTU VI) and Dm28c (DTU I). All strains accomplished metacyclogenesis. Bug strain reached the highest numbers of metacyclic trypomastigotes followed by YuYu and CL-Brener/Dm28c. A remarkable parasite reduction in the AM for Bug strain, but not Dm28c was noticed at 72 h of infection. In the posterior midgut + rectum high densities of parasites from both strains were detected at this period indicating the parasites crossed the AM. For Dm28c strain, in infections initiated with trypomastigotes, parasites left AM faster than those starting with epimastigotes. In conclusion, T. cruzi strains from different DTUs were able to infect T. infestans reaching variable parasite densities. The kinetics of migration in the digestive tract may be affected by strain and/or the evolutive form used for infection.

Asunto(s)

Interacciones Huésped-Parásitos , Insectos Vectores/parasitología , Triatoma/parasitología , Trypanosoma cruzi/crecimiento & desarrollo , Animales , Tracto Gastrointestinal/parasitología , Ninfa/parasitología

RESUMEN

Although Leishmania infantum is well-known as the aethiological agent of visceral leishmaniasis (VL), in some Central American countries it may cause atypical non-ulcerated cutaneous leishmaniasis (NUCL). However, the mechanisms favoring its establishment in the skin are still unknown. Lipophosphoglycan (LPG) is the major Leishmania multivirulence factor involved in parasite-host interaction. In the case of viscerotropic L. infantum, it causes an immunosuppression during the interaction with macrophages. Here, we investigated the biochemical and functional roles of LPGs from four dermotropic L. infantum strains from Honduras during in vitro interaction with murine macrophages. LPGs were extracted, purified and their repeat units analysed. They did not have side chains consisting of Gal(ß1,4)Man(α1)-PO4 common to all LPGs. Peritoneal macrophages from BALB/c and C57BL/6 were exposed to LPG for nitric oxide (NO) and cytokine (TNF-α and, IL-6) production. LPGs from dermotropic strains from Honduras triggered higher NO and cytokine levels compared to those from viscerotropic strains. In conclusion, LPGs from dermotropic strains are devoid of side-chains and exhibit high pro-inflammatory activity.

Asunto(s)

Glicoesfingolípidos , Leishmania infantum/fisiología , Animales , América Central , Honduras , Humanos , Macrófagos/inmunología , Masculino , Ratones

RESUMEN

Although Leishmania infantum is well-known as the aethiological agent of visceral leishmaniasis (VL), in some Central American countries it may cause atypical non-ulcerated cutaneous leishmaniasis (NUCL). However, the mechanisms favoring its establishment in the skin are still unknown. Lipophosphoglycan (LPG) is the major Leishmania multivirulence factor involved in parasite-host interaction. In the case of viscerotropic L. infantum, it causes an immunosuppression during the interaction with macrophages. Here, we investigated the biochemical and functional roles of LPGs from four dermotropic L. infantum strains from Honduras during in vitro interaction with murine macrophages. LPGs were extracted, purified and their repeat units analysed. They did not have side chains consisting of Gal(β1,4)Man(α1)-PO4 common to all LPGs. Peritoneal macrophages from BALB/c and C57BL/6 were exposed to LPG for nitric oxide (NO) and cytokine (TNF-α and, IL-6) production. LPGs from dermotropic strains from Honduras triggered higher NO and cytokine levels compared to those from viscerotropic strains. In conclusion, LPGs from dermotropic strains are devoid of side-chains and exhibit high pro-inflammatory activity.

Asunto(s)

Humanos , Animales , Masculino , Ratones , Glicoesfingolípidos , Leishmania infantum/fisiología , América Central , Honduras , Macrófagos/inmunología

RESUMEN

The protozoan Trypanosoma cruzi has the ability to spontaneously secrete extracellular vesicles (EVs). In this paper, T. cruzi EVs derived from epimastigote forms were evaluated during interaction with triatomine bugs Rhodnius prolixus and Triatoma infestans. T. cruzi EVs were purified and artificially offered to the insects prior to infection with epimastigote forms. No effect of EVs was detected in the parasite counts in the guts of both vectors after 49-50 days. On the other hand, pre-feeding with EVs delayed parasite migration to rectum only in the gut in R. prolixus after 21-22 days. Those data suggest a possible role of T. cruzi EVs during the earlier events of infection in the invertebrate host.

Asunto(s)

Vesículas Extracelulares , Insectos Vectores/parasitología , Intestinos/parasitología , Rhodnius/parasitología , Triatoma/parasitología , Trypanosoma cruzi/fisiología , Animales , Interacciones Huésped-Parásitos/fisiología , Trypanosoma cruzi/citología

RESUMEN

Activation of the NLRP3 inflammasome by Leishmania parasites is critical for the outcome of leishmaniasis, a disease that affects millions of people worldwide. We investigate the mechanisms involved in NLRP3 activation and demonstrate that caspase-11 (CASP11) is activated in response to infection by Leishmania species and triggers the non-canonical activation of NLRP3. This process accounts for host resistance to infection in macrophages and in vivo. We identify the parasite membrane glycoconjugate lipophosphoglycan (LPG) as the molecule involved in CASP11 activation. Cytosolic delivery of LPG in macrophages triggers CASP11 activation, and infections performed with Lpg1-/- parasites reduce CASP11/NLRP3 activation. Unlike bacterial LPS, purified LPG does not activate mouse CASP11 (or human Casp4) in vitro, suggesting the participation of additional molecules for LPG-mediated CASP11 activation. Our data identify a parasite molecule involved in CASP11 activation, thereby establishing the mechanisms underlying inflammasome activation in response to Leishmania species.

Asunto(s)

Caspasas Iniciadoras/metabolismo , Glicoesfingolípidos/metabolismo , Inflamasomas/metabolismo , Leishmania/metabolismo , Leishmania/patogenicidad , Leishmaniasis/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Animales , Células Cultivadas , Células HEK293 , Humanos , Leishmaniasis/parasitología , Macrófagos/metabolismo , Macrófagos/parasitología , Ratones , Ratones Endogámicos C57BL

RESUMEN

Leishmania (Viannia) braziliensis is the most common etiological agent of cutaneous and mucocutaneous leishmaniasis (MCL) in Latin America. An interesting aspect of the disease outcome caused by this species is the appearance of non-ulcerated atypical cutaneous leishmaniasis. Atypical (AT) lesions are often associated with therapeutic failure when treated with antimony(Sb)-based drugs. Refractory cases are not necessarily due to intrinsic parasite drug resistance. The status of in vitro drug susceptibility from L. braziliensis field isolates is less assessed than patient treatment outcome. In this work, L. braziliensis isolated from typical CL (6), MCL (1) and AT (3) lesions and vector (1) were tested for their susceptibility to amphotericin B (AmB), miltefosine (MIL), glucantime (GLU) and non-comercial meglumine antimoniate (MA). Overall, intracellular amastigotes of all isolates were sensitive to the tested antileishmanial drugs except AT lesions-derived strains 316, 330 and 340 that presented in vitro resistance against SbV-based drugs. Although susceptible to miltefosine - based on phenotypic screening - intramacrophagic quiescent amastigotes could restore infection. L. braziliensis promastigotes isolated from AT lesions also displayed 29% reduced capacity to infect human monocyte-derived macrophages when compared with parasites obtained from patients with typical lesions, MCL or from sand-fly. These data indicate differences in drug susceptibility and infectiveness among L. braziliensis isolated from patients exhibiting different types of lesions and highlight the importance of its characterization for drug response prediction outcome in clinical practice.

Asunto(s)

Antimonio/farmacología , Antiprotozoarios/farmacología , Resistencia a Medicamentos/efectos de los fármacos , Leishmania braziliensis/efectos de los fármacos , Leishmania braziliensis/aislamiento & purificación , Leishmaniasis Cutánea/parasitología , Anfotericina B/farmacología , Humanos , Especificidad de la Especie , Células THP-1

RESUMEN

The subgenus Mundinia includes several Leishmania species that have human and veterinary importance. One of those members, Leishmania Mundinia enriettii was isolated from the guinea pig Cavia porcellus in the 1940s. Several histopathological studies have already been performed in this species in the absence of salivary gland extract (SGE), which are determinant and the early and future events of the infection. Our main hypothesis is that SGE could differentially modulate the course of the lesion and macrophage differentiation caused by avirulent and virulent L. enriettii strains. Here, the C. porcellus nasal region was infected using needles with two strains of L. enriettii (L88 and Cobaia) in the presence/absence of SGE and followed for 12 weeks. Those strains vary in terms of virulence, and their histopathological development was characterized. Some L88-infected animals could develop ulcerated/nodular lesions, whereas Cobaia strain developed non-ulcerated nodular lesions. Animals experimentally inoculated developed a protuberance and/or lesion after the 4th and 5th weeks of infection. Macroscopically, the size of lesion in L88-infected animals was smaller in the presence of SGE. Remarkable differences were detected microscopically in the presence of SGE for both strains. After the 6th and 7th weeks, L88-infected animals were heavily parasitized with an intense inflammatory profile bearing amastigotes and pro-inflammatory cells compared to those infected by Cobaia strain. Morphometry analysis revealed that L1+ macrophages were abundant in the L88 infection, but not in the Cobaia infection. In the presence of SGE, an increased CD163+ macrophage infiltrate by both strains was detected. Interestingly, this effect was more pronounced in Cobaia-infected animals. This study showed the role of SGE during the course of L. enriettii (strains L88 and Cobaia) infection and its role in modulating macrophage attraction to the lesion site. SGE decreased L1+ macrophages and this may favor an escaping mechanism for L88 parasites. On the other hand, in the presence of SGE, an increase in CD163+ cells during Cobaia infection may be important for its control. Although both strains healed at the end of the infection, the role of SGE was determinant for the kinetics of the immunopathological events in this dermotropic species.

RESUMEN

: Trypanosoma cruzi and Leishmania sp. are important protozoan parasites for humans and animals in the Americas, causing Chagas disease and cutaneous or visceral leishmaniasis, respectively. These vector-borne diseases affect permanent and transient populations in developing tropical countries that exhibit favorable conditions for the perpetuation of the parasite cycle. Our objective was to investigate the occurrence of infection with these parasites in wild animals from urban rainforest fragments in the city of Salvador, the largest city in the northeast region of Brazil. Sixty-five wild animals were captured, clinically examined, and sampled for parasite detection by PCR and culture. Ten different mammalian genera were identified, being 58% (38/65) marsupials. The prevalence of T. cruzi and Leishmania sp. infections was 13% and 43%, respectively. Both parasites were detected by PCR in 11% (7/65), three of which were also double infected as determined by culture. Among the 28 animals found infected with at least one parasite (43%, 28/65), 68% (19/28) were marsupials, two specimens were Callithrix sp. (7%), and one was Trinomys sp. (3%). Most infected animals (89%) had no clinical signs of disease. We found that healthy free-living animals from urban rainforest fragments harbored pathogenic trypanosomatids and should be included in epidemiology studies of diseases in big cities in tropical countries, as these cities grow and engulf rainforest remnants.

Asunto(s)

Animales Salvajes , Enfermedad de Chagas/veterinaria , Leishmania , Leishmaniasis/veterinaria , Trypanosoma cruzi , Animales , Brasil/epidemiología , Callithrix , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/parasitología , Bosques , Leishmaniasis/epidemiología , Leishmaniasis/parasitología , Marsupiales , Roedores , Población Urbana

RESUMEN

One of the Leishmania species known to be non-infective to humans is Leishmania (Mundinia) enriettii whose vertebrate host is the guinea pig Cavia porcellus. It is a good model for cutaneous leishmaniasis, chemotherapeutic and molecular studies. In the last years, an increased interest has emerged concerning the L. (Mundinia) subgenus after the finding of Leishmania (M.) macropodum in Australia and with the description of other new/putative species such as L. (M.) martiniquensis and 'L. (M.) siamensis'. This review focused on histopathology, glycoconjugates and innate immunity. The presence of Leishmania RNA virus and shedding of extracellular vesicles by the parasite were also evaluated.

Asunto(s)

Vesículas Extracelulares/fisiología , Interacciones Huésped-Parásitos , Leishmania/patogenicidad , Leishmaniasis Cutánea/patología , Animales , Australia , Modelos Animales de Enfermedad , Cobayas/parasitología , Inmunidad Innata , Leishmania/clasificación , Leishmania/virología , Leishmaniasis Cutánea/inmunología , Virus ARN

RESUMEN

BACKGROUND: Lipophosphoglycan (LPG) is a dominant surface molecule of Leishmania promastigotes. Its species-specific polymorphisms are found mainly in the sugars that branch off the conserved Gal(ß1,4)Man(α1)-PO4 backbone of repeat units. Leishmania amazonensis is one of the most important species causing human cutaneous leishmaniasis in the New World. Here, we describe LPG intraspecific polymorphisms in two Le. amazonensis reference strains and their role during the development in three sand fly species. RESULTS: Strains isolated from Lutzomyia flaviscutellata (PH8) and from a human patient (Josefa) displayed structural polymorphism in the LPG repeat units, possessing side chains with 1 and 2 ß-glucose or 1 to 3 ß-galactose, respectively. Both strains successfully infected permissive vectors Lutzomyia longipalpis and Lutzomyia migonei and could colonize their stomodeal valve and differentiate into metacyclic forms. Despite bearing terminal galactose residues on LPG, Josefa could not sustain infection in the restrictive vector Phlebotomus papatasi. CONCLUSIONS: LPG polymorphisms did not affect the ability of Le. amazonensis to develop late-stage infections in permissive vectors. However, the non-establishment of infection in Ph. papatasi by Josefa strain suggested other LPG-independent factors in this restrictive vector.

Asunto(s)

Glicoesfingolípidos/análisis , Leishmania/química , Leishmania/crecimiento & desarrollo , Psychodidae/parasitología , Animales , Humanos , Leishmania/aislamiento & purificación

Asunto(s)

Leishmania enriettii , Leishmaniasis/parasitología , Animales , Humanos , Insectos Vectores/parasitología , Leishmaniasis/transmisión

RESUMEN

American tegumentary leishmaniasis (ATL) is a neglected disease widely distributed in Latin America. In Brazil, it is caused by different Leishmania species belonging to the Subgenera Viannia and Leishmania. ATL diagnosis is routinely based on clinical, epidemiological, parasitological and immunological (delayed-type hypersensitivity skin test-DTH) evidences. The main objective of this work was to determine the efficacy of a previous immunohistochemical (IHC) method developed by our group. Seventy eight skin biopsies from patients with different ATL clinical forms and origins were evaluated. The method was previously standardized in ATL patients from the municipality of Caratinga, Minas Gerais, Brazil, all infected with Leishmania (V.) braziliensis. Here, it is evaluated in patients from the North, Southeast and Midwest regions of Brazil. Clinical, parasitological (biopsy PCR) and immunological (Montenegro skin test-MST) diagnosis were performed prior to IHC procedure. The IHC procedure detected 70.5% of the cases having a high agreement with MST diagnosis (kappa=0.84). A distinguished contribution of this work is that IHC succeed in diagnosing some negative DTH patients. Those were infected with Leishmania (L.) amazonensis, commonly causing the anergic form of the disease. In conclusion, IHC succeed in detecting ATL caused by different Leishmania species from various geographic regions and clinical status. Although it was not able to detect ATL in all patients, it was better than MST providing an additional tool for the diagnosis of ATL patients. There was no significant correlation between clinical forms and histological features including the presence of necrosis.

Asunto(s)

Inmunohistoquímica , Leishmania/aislamiento & purificación , Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Cutánea/parasitología , Piel/parasitología , Adolescente , Adulto , Anciano , Biopsia , Brasil/epidemiología , Femenino , Humanos , Leishmania/genética , Leishmania/inmunología , Leishmania braziliensis/inmunología , Leishmania braziliensis/aislamiento & purificación , Leishmaniasis Cutánea/epidemiología , Hígado/parasitología , Hígado/patología , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Piel/patología , Piel/ultraestructura , Estados Unidos , Adulto Joven

RESUMEN

The double stranded RNA (dsRNA) virus Leishmaniavirus (Totiviridae) was first described in Leishmania guyanensis and L. braziliensis (LRV1), and more recently from L. major and L. aethiopica (LRV2). Parasites bearing LRV1 elicit a higher pro-inflammatory profile, arising through activation of Toll like receptor 3(TLR3) interacting with the viral dsRNA. LRV1 is most common in Leishmania from the Amazon region; however data for other regions of Brazil are more limited. Here we applied PCR tests with validated 'universal' LRV1 primers to search for LRV1 in 40 strains of cultured L. braziliensis from several locales within Minas Gerais State, including patients presenting with atypical lesion pathology. All strains were negative however. These data are in agreement with results from other areas of Southeastern Brazil that LRV1 is relatively uncommon.

Asunto(s)

Leishmania braziliensis/clasificación , Leishmaniasis Cutánea/epidemiología , Leishmaniasis Cutánea/parasitología , Brasil/epidemiología , Geografía Médica , Humanos , Leishmania braziliensis/aislamiento & purificación , Vigilancia de la Población , Prevalencia

RESUMEN

The immunomodulatory properties of lipophosphoglycans (LPG) from New World species of Leishmania have been assessed in Leishmania infantum and Leishmania braziliensis, the causative agents of visceral and cutaneous leishmaniasis, respectively. This glycoconjugate is highly polymorphic among species with variation in sugars that branch off the conserved Gal(ß1,4)Man(α1)-PO4 backbone of repeat units. Here, the immunomodulatory activity of LPGs from Leishmania amazonensis, the causative agent of diffuse cutaneous leishmaniasis, was evaluated in two strains from Brazil. One strain (PH8) was originally isolated from the sand fly and the other (Josefa) was isolated from a human case. The ability of purified LPGs from both strains was investigated during in vitro interaction with peritoneal murine macrophages and CHO cells and in vivo infection with Lutzomyia migonei. In peritoneal murine macrophages, the LPGs from both strains activated TLR4. Both LPGs equally activate MAPKs and the NF-κB inhibitor p-IκBα, but were not able to translocate NF-κB. In vivo experiments with sand flies showed that both stains were able to sustain infection in L. migonei. A preliminary biochemical analysis indicates intraspecies variation in the LPG sugar moieties. However, they did not result in different activation profiles of the innate immune system. Also those polymorphisms did not affect infectivity to the sand fly.

Asunto(s)

Glicoesfingolípidos/química , Glicoesfingolípidos/inmunología , Interacciones Huésped-Parásitos , Leishmania mexicana/química , Macrófagos Peritoneales/inmunología , Psychodidae/parasitología , Receptor Toll-Like 4/inmunología , Animales , Brasil , Células CHO , Cricetulus , Citocinas/inmunología , Glicoesfingolípidos/aislamiento & purificación , Interacciones Huésped-Parásitos/inmunología , Humanos , Inmunidad Innata/efectos de los fármacos , Leishmaniasis Cutánea/parasitología , Ratones , Quinasas de Proteína Quinasa Activadas por Mitógenos/efectos de los fármacos , Receptor Toll-Like 4/genética

RESUMEN

Leishmania major, the causative agent of zoonotic leishmaniasis, is restricted to Old World countries. Molecular and biochemical techniques have been used to identify some L. major-like isolated in South America including Brazil. Here, two L. major-like strains, one virulent (BH49) and one non-virulent (BH121), were subjected to suppression subtractive hybridization (SSH) technique in order to identify differentially expressed genes. SSH technique identified nine cDNA fragments exhibiting high homology to previously sequenced L. major genes. Five cDNAs (four specific for BH49 and one for BH121) were confirmed by RT-PCR. Among those differentially expressed subtracted genes, some were involved in physiological processes including metabolism, translation and destination of proteins, production of energy, virulence factors and unknown functions. Western-blot analysis confirmed a higher expression level of ß-1,3-galactosyl residues in L. major-like lipophosphoglycan (LPG). This molecular analysis opens the possibility for identification of potential virulence factors not only in different strains, but also in others species of Leishmania.

Asunto(s)

ADN Protozoario/genética , Leishmania major/genética , Leishmaniasis Cutánea/parasitología , Animales , Cricetinae , ADN Complementario/genética , Galactosiltransferasas/metabolismo , Glicoesfingolípidos/metabolismo , Humanos , Leishmania major/patogenicidad , Macrófagos/parasitología , Mesocricetus , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Enfermedades Desatendidas/parasitología , Proteínas Protozoarias/metabolismo , Homología de Secuencia de Ácido Nucleico , Técnicas de Hibridación Sustractiva , Virulencia/genética