Dissemination of Leishmania (Viannia) braziliensis

Almeida, Marcos Célio de; Cuba-Cuba, César Augusto; Moraes, Mário Augusto Pinto de; Miles, Michael A.

doi:10.1016/s0021-9975(96)80088-0

Cited by 18 publications

(17 citation statements)

References 19 publications

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“…distant from the inoculation site is considered a common finding in hamsters and mice that are experimentally infected with inocula that contain a high parasite concentration (13,15,17,39,40). This also correlated with lesion size and consequently with infection severity (15).…”

Section: Discussionmentioning

confidence: 95%

“…Considering that hamsters present an outbred genetic background, it is expected that individual characteristics have an important role in different clinical outcomes of the disease, in such a way that they may reproduce immune responses observed in the human disease. Despite these advantages, few studies have involved L. braziliensis infection in the hamster model, and the protocols vary among them in terms of isolate and inoculum size (13,16,17). However, even when an infection is established with the same parasite numbers and L. braziliensis strain, the lesion development is variable.…”

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confidence: 99%

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Comparative Evaluation of Lesion Development, Tissue Damage, and Cytokine Expression in Golden Hamsters (Mesocricetus auratus) Infected by Inocula with Different Leishmania (Viannia) braziliensis Concentrations

et al. 2014

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The golden hamster (Mesocricetus auratus) is a susceptible model to Leishmania (Viannia) spp.; however, available studies employ different infection protocols, which account for clinical and pathological presentation differences. Herein, L. (V.) braziliensis preparations were standardized to contain 10 4 , 10 5 , or 10 6 parasites to determine an optimal inoculum that ensured cutaneous lesions without causing a disseminated infection in hamsters. Lesion development was followed for 105 days by size measurements, and skin, draining lymph node, spleen, and sera were investigated to check parasite load, spleen visceralization, cytokine expression, histopathological changes, and anti-Leishmania IgG levels. The lesion emergence time was inversely proportional to the parasite concentration in the inocula. Animals infected by 10 4 parasites presented nodular lesions, while those infected with 10 6 parasites often exhibited ulcerated lesions. The differences in the final lesion sizes were observed between 10 4 and 10 5 inocula or 10 4 and 10 6 inocula. High IFNG expression, anti-Leishmania IgG levels, and parasite load occurred independently of the inoculum used. A mild inflammatory skin involvement was observed in animals infected with 10 4 parasites, while extensive tissue damage and parasite spleen visceralization occurred with 10 5 and 10 6 parasites. These results indicate that inocula with different concentrations of parasites generate differences in the time of lesion emergence, clinical presentation, and systemic commitment, despite high and similar IFNG expression and parasite load. This suggests that a modulation in the immune response to different parasite numbers occurs in an early phase of the infection, which could dictate the establishment and magnitude of the chronic phase of the disease.

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Section: Discussionmentioning

confidence: 95%

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confidence: 99%

Comparative Evaluation of Lesion Development, Tissue Damage, and Cytokine Expression in Golden Hamsters (Mesocricetus auratus) Infected by Inocula with Different Leishmania (Viannia) braziliensis Concentrations

et al. 2014

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“…32 . Nevertheless, it would be of interest to compare the metastatic potential of the hybrid and nonhybrid genotypes in the hamster model of MCL 33 or perhaps in the mouse ear model for dissemination. 34 The occurrence of L.…”

Section: Discussionmentioning

confidence: 99%

Multiple Hybrid Genotypes of Leishmania (Viannia) in a Focus of Mucocutaneous Leishmaniasis

Nolder¹,

Roncal²,

Davies³

et al. 2007

The American Journal of Tropical Medicine and Hygiene

106

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Abstract. The principal agent of mucocutaneous leishmaniasis (MCL) is the South American protozoan parasite Leishmania (Viannia) braziliensis. This organism is generally considered to be clonal, that is, it does not to undergo genetic exchange. Nevertheless, apparent hybrids between several Leishmania species have been reported in the New World and the Old World. When we characterized isolates of Leishmania (Viannia) from a single focus of cutaneous leishmaniasis (CL) and MCL, we found a remarkable phenotypic and genotypic diversity, with 12 zymodemes and 20 microsatellite genotypes. Furthermore, 26 of the 59 isolates were L. braziliensis/L. peruviana phenotypic hybrids that displayed 7 different microsatellite genotypes. A hybrid genotype was the only organism isolated from 4 patients with MCL. Thus hybrids must be included among the potential agents of MCL. Despite the propensity for clonality, hybrids are also an important feature of Leishmania (Viannia) and may give rise to epidemiologically important emergent genotypes.

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“…In the literature there are several reports on the activity of a variety of crude natural extracts, especially from plants collected in tropical zones, against Leishmania species of the New World (Fournet et al 1994, Akendengue et al 1999, Weniger et al 2001, Fournet & Munoz 2002. Most of these studies were performed with L. amazonensis and L. braziliensis that cause the cutaneous form of the disease (Lainson 1983, Hepburn 2000, and as second pathology, the first species led to the diffuse cutaneous form (Garnier & Croft 2002), and the second one to the mucocutaneous disease (Jones et al 1987, Almeida et al 1996; and also with L. chagasi the causal agent of visceral leishmaniasis (Lainson et al 1987, Davidson 1999.Our group has been engaged for several years in the investigation of propolis effect against pathogenic trypanosomatids, especially Trypanosoma cruzi, agent of Chagas disease (De Castro & Higashi 1995, Marcucci et al 2001, Cunha et al 2004, Dantas et al 2005. Propolis is a resinous substance that honeybees use to fill gaps and to seal parts of the hive and is collected from different plant exudates resulting in a complex mixture containing known bioactive constituents (Bankova et al 2000).…”

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Activity of Brazilian and Bulgarian propolis against different species of Leishmania

Machado¹,

Leon²,

Castro

2007

Mem. Inst. Oswaldo Cruz

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Extracts of propolis samples collected in Brazil and (WHO 2004). No vaccines are available for any form of the disease, and the chemotherapy of this disease is still inadequate and expensive (Croft & Yardley 2002). In this context, there is an intense search for potential new synthetic compounds and natural products for the treatment of leishmaniasis. In the last decades occurred a movement sometimes called "back to Nature", which in the area of drug development was accentuated by the success obtained, for example, by taxol in cancer chemotherapy and artemisinin for malaria (Newman et al. 2003). Such intensification in the search for drugs from natural sources was also observed in the area of leishmaniasis. In the literature there are several reports on the activity of a variety of crude natural extracts, especially from plants collected in tropical zones, against Leishmania species of the New World (Fournet et al. 1994, Akendengue et al. 1999, Weniger et al. 2001, Fournet & Munoz 2002. Most of these studies were performed with L. amazonensis and L. braziliensis that cause the cutaneous form of the disease (Lainson 1983, Hepburn 2000, and as second pathology, the first species led to the diffuse cutaneous form (Garnier & Croft 2002), and the second one to the mucocutaneous disease (Jones et al. 1987, Almeida et al. 1996; and also with L. chagasi the causal agent of visceral leishmaniasis (Lainson et al. 1987, Davidson 1999.Our group has been engaged for several years in the investigation of propolis effect against pathogenic trypanosomatids, especially Trypanosoma cruzi, agent of Chagas disease (De Castro & Higashi 1995, Marcucci et al. 2001, Cunha et al. 2004, Dantas et al. 2005. Propolis is a resinous substance that honeybees use to fill gaps and to seal parts of the hive and is collected from different plant exudates resulting in a complex mixture containing known bioactive constituents (Bankova et al. 2000). This product possesses microbicidal, anti-inflammatory, and anti-tumoral activities, which have been associated with the presence of phenolic compounds (reviewed in De Castro 2001). We have previously determined the chemical composition as well as the analgesic and anti-inflammatory activities of a standard ethanol extract of a Bulgarian sample (Et-Blg) (Prytzyk et al. 2003, Paulino et al. 2003) and compared its activity to that of a corresponding Brazilian extract (EtBra) against T. cruzi and several species of fungi and bacteria of medical importance . In the present work, we analyzed the effect of these extracts against different species of Leishmania. MATERIALS AND METHODSPropolis samples -The Bulgarian propolis (Blg) sample was collected at Burgas (Southeast Bulgaria) (Prytzyk et al. 2003) and the Brazilian one (Bra) at Mar de Espanha (state of Minas Gerais, Brazil) ). The exudates collected by bees in Bulgaria were mainly from buds of Populus nigra, and those in Brazil from a mixture of tropical plants. Each sample was cut in small pieces, after cooling bellow -10°C and extracted with 70% ethanol (...

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Dissemination of Leishmania (Viannia) braziliensis

Cited by 18 publications

References 19 publications

Comparative Evaluation of Lesion Development, Tissue Damage, and Cytokine Expression in Golden Hamsters (Mesocricetus auratus) Infected by Inocula with Different Leishmania (Viannia) braziliensis Concentrations

Comparative Evaluation of Lesion Development, Tissue Damage, and Cytokine Expression in Golden Hamsters (Mesocricetus auratus) Infected by Inocula with Different Leishmania (Viannia) braziliensis Concentrations

Multiple Hybrid Genotypes of Leishmania (Viannia) in a Focus of Mucocutaneous Leishmaniasis

Activity of Brazilian and Bulgarian propolis against different species of Leishmania

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