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Costa JCR, Marchi GH, Santos CS, Andrade MCM, Chaves Junior SP, Silva MAN, Melo MN, Andrade AJ. First molecular evidence of frogs as a food source for sand flies (Diptera: Phlebotominae) in Brazilian caves. Parasitol Res 2021; 120:1571-1582. [PMID: 33852067 DOI: 10.1007/s00436-021-07154-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/05/2021] [Indexed: 12/15/2022]
Abstract
Genus and species of phlebotomine sand flies have been recorded and described in caves in Brazil, but no study has provided the food source used by sand flies in these environments. Herein, we identified the blood source used by sand fly species in caves located at "Quadrilátero Ferrífero" (QF), Minas Gerais state. Specimens were manually collected near or on anurans inside ferruginous caves in Serra do Gandarela National Park and Serra do Rola Moça State Park. Males and females were placed in vials with 70% alcohol and stored at -10°C. Females engorged, after specific identification, had DNA extracted and followed for PCR amplification using specific primers. Sequencing was analyzed in the GenBank and Barcode of Life. A total of 198 specimens were collected (107 females and 91 males), all of them belonging to species Sciopemyia aff. microps (88.89%), Sciopemyia sordellii (10.61%), or Martinsmyia oliveirai (0.50%). When it comes to the females, 89 were S. aff. microps and 18 S. sordellii. Nineteen engorged females of S. aff. microps were analyzed and most of them (n=18) presented blood from Bokermannohyla martinsi and one contained blood from Scinax fuscovarius. The blood present in engorged females of S. sordellii (n=4) was from B. martinsi. Sciopemyia genus specimens are commonly found in collections carried out inside natural caves, but this was the first study to prove that females of this genus feed on cold-blooded animals in nature. HIGHLIGHTS: • Here we proved that sand flies feed in cold-blooded animals in in Brazilian caves. • Females of the Sciopemyia genus were for the first time found feeding in natural habitats. • Anurans of the family Hylidae were identified as source by molecular analyzes. • Insect bloodmeal identification can help assessing the fauna in several biomes. • This is the first record of S. aff. microps in caves of Brazil.
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Affiliation(s)
- J C R Costa
- Chico Mendes Institute for Biodiversity Conservation, National Cave Research and Conservation Center, Nova Lima, MG, Brazil
| | - G H Marchi
- Basic Pathology Department, Federal University of Paraná, Curitiba, PR, Brazil
| | - C S Santos
- Zoology Department, Federal University of Paraná, Curitiba, PR, Brazil
| | - M C M Andrade
- Chico Mendes Institute for Biodiversity Conservation, National Cave Research and Conservation Center, Nova Lima, MG, Brazil
| | - S P Chaves Junior
- Basic Pathology Department, Federal University of Paraná, Curitiba, PR, Brazil
| | - M A N Silva
- Zoology Department, Federal University of Paraná, Curitiba, PR, Brazil
| | - M N Melo
- Parasitology Department, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - A J Andrade
- Basic Pathology Department, Federal University of Paraná, Curitiba, PR, Brazil.
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Oliveira RS, Pimentel KBA, Moura ML, Aragão CF, Guimarães-E-Silva AS, Bezerra JMT, Melo MN, Pinheiro VCS. Clinical, epidemiological and climatic factors related to the occurrence of cutaneous leishmaniasis in an endemic area in northeastern Brazil. BRAZ J BIOL 2021; 81:557-565. [PMID: 32876165 DOI: 10.1590/1519-6984.224937] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 02/26/2020] [Indexed: 01/19/2023] Open
Abstract
Cutaneous leishmaniasis (CL) is a neglected tropical disease with a wide distribution in the Americas. Brazil is an endemic country and present cases in all states. This study aimed to describe the occurrence, the underlying clinical and epidemiological factors, and the correlation of climatic variables with the frequency of reported CL cases in the municipality of Caxias, state of Maranhão, Brazil. This is a retrospective and descriptive epidemiological study based on data extracted from the Brazilian Information System of Diseases Notification, from 2007 to 2017. Maximum and minimum temperature, precipitation, and relative air humidity data were provided by the Brazilian National Institute of Meteorology. A total of 201 reported autochthonous CL cases were analyzed. The predominance of cases was observed in males (70.1%). The age range between 31 and 60 years old was the most affected, with 96 cases (47.9%). Of the total number of registered cases, 38.8% of the affected individuals were engaged in agriculture-related activities. The georeferenced distribution revealed the heterogeneity of disease occurrence, with cases concentrated in the Western and Southern regions of the municipality. An association was detected between relative air humidity (monthly mean) and the number of CL cases per month (p = 0.04). CL continues to be a concerning public health issue in Caxias. In this context, there is a pressing need to strengthen measures of prevention and control of the disease through the network of health services of the municipality, considering local and regional particularities.
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Affiliation(s)
- R S Oliveira
- Curso de Medicina, Departamento de Ciências da Saúde, Universidade Estadual do Maranhão - UEMA, Campus Caxias - Anexo Saúde, Rua Quinhinha Pires, 746, Centro, CEP 65602-050, Caxias, MA, Brasil
| | - K B A Pimentel
- Programa de Pós-graduação Strictu Sensu em Saúde e Ambiente, Universidade Federal do Maranhão - UFMA, Praça Madre Deus, 02, Madre Deus, CEP 65025-560, São Luís, MA, Brasil
| | - M L Moura
- Curso de Medicina, Departamento de Ciências da Saúde, Universidade Estadual do Maranhão - UEMA, Campus Caxias - Anexo Saúde, Rua Quinhinha Pires, 746, Centro, CEP 65602-050, Caxias, MA, Brasil
| | - C F Aragão
- Programa de Pós-graduação Strictu Sensu em Virologia, Instituto Evandro Chagas - IEC, Rodovia BR 316, Km 07, s/n, Levilândia, CEP 67030-000, Ananideua, PA, Brasil
| | - A S Guimarães-E-Silva
- Programa de Pós-graduação Strictu Sensu em Biodiversidade, Ambiente e Saúde, Laboratório de Entomologia Médica, Universidade Estadual do Maranhão - UEMA, Campus Caxias, Praça Duque de Caxias, s/n, Morro do Alecrim, CEP 65604-380, Caxias, MA, Brasil
| | - J M T Bezerra
- Curso de Ciências Biológicas, Universidade Estadual do Maranhão - UEMA, Campus Lago da Pedra, Avenida Roseana Sarney, s/n, Vila Rocha, CEP 65715-000, Lago da Pedra, MA, Brasil
| | - M N Melo
- Laboratório de Biologia de Leishmania, Departamento de Parasitologia, Universidade Federal de Minas Gerais - UFMG, Av. Presidente Antônio Carlos, 6627, Pampulha, CEP 31270-901, Belo Horizonte, MG, Brasil
| | - V C S Pinheiro
- Programa de Pós-graduação Strictu Sensu em Biodiversidade, Ambiente e Saúde, Laboratório de Entomologia Médica, Universidade Estadual do Maranhão - UEMA, Campus Caxias, Praça Duque de Caxias, s/n, Morro do Alecrim, CEP 65604-380, Caxias, MA, Brasil
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Abstract
Sterols play an essential role in modulating bilayer structure and dynamics. Coarse-grained molecular dynamics parameters for cholesterol and related molecules are available for the Martini force field and have been successfully used in multiple lipid bilayer studies. In this work, we focus on the use of virtual sites as a means of increasing the stability of cholesterol and cholesterol-like structures. We improve and extend the Martini parameterization of sterols in four different ways: 1-the cholesterol parameters were adapted to make use of virtual interaction sites, which markedly improves numerical stability; 2-cholesterol parameters were also modified to address reported shortcomings in reproducing correct lipid phase behavior in mixed membranes; 3-parameters for ergosterol were created and adapted from cholesterols; and 4-parameters for the hopanoid class of bacterial polycyclic molecules were created, namely, for hopane, diploptene, bacteriohopanetetrol, and for their polycyclic base structure.
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Affiliation(s)
- M N Melo
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - H I Ingólfsson
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - S J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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Zavadlav J, Melo MN, Marrink SJ, Praprotnik M. Adaptive resolution simulation of an atomistic protein in MARTINI water. J Chem Phys 2014; 140:054114. [DOI: 10.1063/1.4863329] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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van Hell AJ, Gueth DM, Melo MN, Marrink SJ, Verheij M. Abstract 2750: Short-chain lipids catalyse intracellular drug accumulation by a transient molecular gateway that allows plasma membrane traversal. Cancer Res 2012. [DOI: 10.1158/1538-7445.am2012-2750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
BACKGROUND: The lipid composition of the plasma membrane provides an effective barrier towards exogenous, potentially cytotoxic molecules. As a consequence, membrane traversal of most therapeutic drugs is sub-optimal and remains a major limitation for clinical efficacy. We previously identified a class of short-chain sphingolipids that facilitate the accumulation of amphiphilic compounds, including the cytostatic drug doxorubicin, within tumor cells, leading to improved therapy response. AIM: In order to elucidate the mechanism of action of short-chain lipids, both in vitro and model membrane studies and in silico molecular dynamics simulation experiments were designed. RESULTS: We demonstrate that short-chain sphingolipids act at the level of the plasma membrane, however, independently of lipid microdomain (raft) formation or membrane proteins. In artificial lipid membranes of well-defined compositions short-chain sphingolipids enhanced doxorubicin-membrane traversal similar to cell membranes; N-octanoyl-glucosylceramide decreased the translocation half-time of doxorubicin over liquid ordered lipid membranes by a factor 1.93 (p < 0.05). In case of liquid disordered membranes, a comparable effect was observed (factor 1.91; p < 0.05); lipid phase separation (raft formation) did not affect enhanced doxorubicin translocation. Molecular dynamics simulations revealed that the short-chain lipids act by assembling a transient molecular gateway for doxorubicin. Accordingly, the free energy barrier for the hydrophilic head group of the drug to dehydrate and translocate to the opposite side of the membrane is reduced by two-fold (p < 0.05). CONCLUSION: Short-chain lipids catalyse the transbilayer movement of amphiphilic cytostatic drugs to achieve higher intratumoral drug accumulation, and their action is explained by the formation of a transient lipid gateway in the plasma membrane of the tumor cell, thus facilitating drug translocation and subsequent intracellular accumulation.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2750. doi:1538-7445.AM2012-2750
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Maftouni N, Nuno Melo M, Marrink SJ. PMF Analysis for Interaction of Two Different Three Fingered Proteins and Lipid Bilayer: Molecular Dynamics Study. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.2165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
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Margonari C, Soares RP, Andrade-Filho JD, Xavier DC, Saraiva L, Fonseca AL, Silva RA, Oliveira ME, Borges EC, Sanguinette CC, Melo MN. Phlebotomine sand flies (Diptera: Psychodidae) and Leishmania infection in Gafanhoto Park, Divinópolis, Brazil. J Med Entomol 2010; 47:1212-1219. [PMID: 21175074 DOI: 10.1603/me09248] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The potential of Gafanhoto Park as an American cutaneous leishmaniasis (ACL) focus was evaluated by examination of sand fly vectors of the Leishmania parasite. This forest remnant is located in a periurban area of Divin6polis, Brazil, where autochthonous cases of ACL have been reported. Sand fly populations were monitored over a 2-yr period (2006-2008) by using light traps (HP and Shannon). During systematic collections with HP traps, 824 specimens in total (342 males and 482 females) of 21 species were captured. Most prevalent species were as follows: Brumptomyia brumpti (Larrouse), Lutzomyia aragaoi (Costa Lima), Lutzomyia lutziana (Costa Lima), Lutzomyia sordellii (Shannon & Del Ponte), and Lutzomyia whitmani (Antunes & Coutinho). Using Shannon traps, 257 specimens representing 15 species were collected (159 females and 98 males), with a high prevalence of L. whitmani and Lutzomyia neivai (Pinto), both vectors of Leishmania braziliensis (Vianna). To ascertain the level of natural infection, a sample of females captured in Shannon traps was assayed for the presence of Leishmania by using polymerase chain reaction-restriction fragment length polymorphism, where 39% of insects were positive. The most infected species was L. whitmani (29 sand flies; 18.2%), followed by L. neivai (21; 13.2%), Lutzomyia christenseni (Young & Duncan) (five; 3.1%), Lutzomyia pessoai (Coutinho & Barreto) (three; 1.9%), L. aragaoi (one; 0.6%), Lutzomyia fischeri (Pinto) (one; 0.6%), Lutzomyia lenti (Mangabeira) (one; 0.6%), L. lutziana (one; 0.6%), and Lutzomyia monticula (Costa Lima) (one; 0.6%). The finding of potential and incriminated vectors naturally infected with Leishmania reinforces the need of epidemiologic surveillance in the area.
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Affiliation(s)
- C Margonari
- Centro de Pesquisas René Rachou/Fiocruz, Belo Horizonte, MG, Brazil.
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de Amorim IFG, Freitas E, Alves CF, Tafuri WL, Melo MN, Michalick MSM, da Costa-Val AP. Humoral immunological profile and parasitological statuses of Leishmune vaccinated and visceral leishmaniasis infected dogs from an endemic area. Vet Parasitol 2010; 173:55-63. [PMID: 20638182 DOI: 10.1016/j.vetpar.2010.06.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 05/12/2010] [Accepted: 06/21/2010] [Indexed: 10/19/2022]
Abstract
Dogs represent the major reservoir of Leishmaniao chagasi and vaccination against the canine disease is a potential control strategy. However, seroconversion occurs post-vaccine and hence, there is need to discriminate between the former group and naturally infected dogs. The present study represents a comparison of the humoral immunological profiles of both groups using Leishmania soluble antigen (LSA) and fucose-mannose ligand (FML). For both categories, ear skin samples were evaluated immunohistochemically and through PCR, that was also performed in blood specimens, as well as their ability to infect Lutzomyia (Lutzomyia) longipalpis. All these tests showed negative results for the vaccinated dogs. Differences between groups were observed regarding IgG, IgG2 and IgE absorbances as determined by FML-ELISA, and for IgG1 and IgE absorbances as measured by LSA-ELISA, showing that Leishmune-immunised animals and VL naturally infected dogs present different immunological profiles, even though these differences cannot be used to distinguish between these two groups of dogs.
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Affiliation(s)
- I F G de Amorim
- Escola de Veterinária, Universidade Federal de Minas Gerais, Campus Pampulha, 31270-901, Belo Horizonte, MG, Brazil
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Melo MN, Sousa FJR, Carneiro FA, Castanho MARB, Valente AP, Almeida FCL, Da Poian AT, Mohana-Borges R. Interaction of the Dengue virus fusion peptide with membranes assessed by NMR: The essential role of the envelope protein Trp101 for membrane fusion. J Mol Biol 2009; 392:736-46. [PMID: 19619560 PMCID: PMC7094664 DOI: 10.1016/j.jmb.2009.07.035] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 07/06/2009] [Accepted: 07/13/2009] [Indexed: 11/30/2022]
Abstract
Dengue virus (DV) infection depends on a step of membrane fusion, which occurs in the acidic environment of the endosome. This process is mediated by virus surface envelope glycoprotein, in which the loop between residues D98-G112 is considered to be crucial, acting as a fusion peptide. Here, we have characterized functionally and structurally the interaction between the DV fusion peptide and different model membranes by fluorescence and NMR. Its interaction was strongest in dodecylphosphocholine (DPC) micelles and anionic phosphatidylcholine/phosphatidylglycerol vesicles, the only vesicle that was fused by DV fusion peptide. The three-dimensional structure of DV fusion peptide bound to DPC micelles was solved by solution homonuclear NMR with an r.m.s.d. of 0.98 A. The most striking result obtained from the solution structure was the hydrophobic triad formed by residues W101, L107, and F108, pointing toward the same direction, keeping the segment between G102 and G106 in a loop conformation. The interaction of DV fusion peptide with phosphatidylcholine/phosphatidylglycerol vesicles was also mapped by transfer-nuclear Overhauser enhancement (NOE) experiments, in which the majority of the NOE cross-peaks were from the hydrophobic triad, corroborating the DPC-bound structure. Substitution of the residue W101 by an alanine residue completely abolished membrane binding and, thus, fusion by the peptide and its NOE cross-peaks. In conclusion, the 15-residue DV fusion peptide has intrinsic ability to promote membrane fusion, most likely due to the hydrophobic interaction among the residues W101, L107, and F108, which maintains its loop in the correct spatial conformation.
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Affiliation(s)
- Manuel Nuno Melo
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro RJ, Brazil
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Stauffer F, Melo MN, Carneiro FA, Sousa FJR, Juliano MA, Juliano L, Mohana-Borges R, Da Poian AT, Castanho MARB. Interaction between dengue virus fusion peptide and lipid bilayers depends on peptide clustering. Mol Membr Biol 2008; 25:128-38. [PMID: 18307100 DOI: 10.1080/09687680701633091] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Dengue fever is one of the most widespread tropical diseases in the world. The disease is caused by a virus member of the Flaviviridae family, a group of enveloped positive sense single-stranded RNA viruses. Dengue virus infection is mediated by virus glycoprotein E, which binds to the cell surface. After uptake by endocytosis, this protein induces the fusion between viral envelope and endosomal membrane at the acidic environment of the endosomal compartment. In this work, we evaluated by steady-state and time-resolved fluorescence spectroscopy the interaction between the peptide believed to be the dengue virus fusion peptide and large unilamellar vesicles, studying the extent of partition, fusion capacity and depth of insertion in membranes. The roles of the bilayer composition (neutral and anionic phospholipids), ionic strength and pH of the medium were also studied. Our results indicate that dengue virus fusion peptide has a high affinity to vesicles composed of anionic lipids and that the interaction is mainly electrostatic. Both partition coefficient and fusion index are enhanced by negatively charged phospholipids. The location determined by differential fluorescence quenching using lipophilic probes demonstrated that the peptide is in an intermediate depth in the hemilayers, in-between the bilayer core and its surface. Ultimately, these data provide novel insights on the interaction between dengue virus fusion peptide and its target membranes, namely, the role of oligomerization and specific types of membranes.
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Affiliation(s)
- Fausto Stauffer
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Henriques ST, Melo MN, Castanho MARB. How to address CPP and AMP translocation? Methods to detect and quantify peptide internalization in vitro and in vivo (Review). Mol Membr Biol 2007; 24:173-84. [PMID: 17520474 DOI: 10.1080/09687860601102476] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Membrane translocation is a crucial issue when addressing the activity of both cell-penetrating and antimicrobial peptides. Translocation is responsible for the therapeutic potential of cell-penetrating peptides as drug carriers and can dictate the killing mechanisms, selectivity and efficiency of antimicrobial peptides. It is essential to evaluate if the internalization of cell-penetrating peptides is mediated by endocytosis and if it is able to internalize attached cargoes. The mode of action of an antimicrobial peptide cannot be fully understood if it is not known whether the peptide acts exclusively at the membrane level or also at the cytoplasm. Therefore, experimental methods to evaluate and quantify translocation processes are of first importance. In this work, over 20 methods described in the literature for the assessment of peptide translocation in vivo and in vitro, with and without attached macromolecular cargoes, are discussed and their applicability, advantages and disadvantages reviewed. In addition, a classification of these methods is proposed, based on common approaches to detect translocation.
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Affiliation(s)
- Sónia Troeira Henriques
- Centro de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal
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Quintão-Silva MG, Melo MN, Ribeiro MFB. Comparison of duplex PCR and microscopic techniques for the identification of Babesia bigemina and Babesia bovis in engorged female ticks of Boophilus microplus. Zoonoses Public Health 2007; 54:147-51. [PMID: 17456146 DOI: 10.1111/j.1863-2378.2007.01037.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A single-step duplex polymerase chain reaction (PCR) technique and traditional microscopic examination of haemolymph smears were used to detect Babesia bigemina and/or Babesia bovis infection in engorged female ticks of Boophilus microplus recovered from calves raised in an endemic area of the State of Minas Gerais, Brazil. In the PCR amplification of tick-derived DNA, pairs of oligonucleotide primers specific for a 278-bp sequence from B. bigemina and for a 350-bp sequence from B. bovis were used conjointly. The microscopic examination of haemolymph revealed that 16.7% of the engorged ticks were infected with Babesia spp., although no significant differences (rho > 0.05) were found in the infection rate of ticks collected from calves of different age groups. PCR analysis showed that 77.8% of the engorged ticks whose haemolymph contained sporokinetes were infected with B. bigemina, 7.8% with B. bovis and 14.4% with both protozoan species. However, the PCR assay further revealed that, amongst the engorged female ticks whose haemolymph was apparently negative for the presence of sporokinetes, 15.6% were infected with B. bigemina, 2.2% with B. bovis and 10.0% with both species. The duplex PCR method is thus more efficient and sensitive than the microscopic assay and also permits facile identification of the protozoa species present in engorged female ticks.
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Lima WG, Oliveira PS, Caliari MV, Gonçalves R, Michalick MSM, Melo MN, Tafuri WL, Tafuri WL. Histopathological and immunohistochemical study of type 3 complement receptors (CD11b/CD18) in livers and spleens of asymptomatic and symptomatic dogs naturally infected with Leishmania (Leishmania) chagasi. Vet Immunol Immunopathol 2007; 117:129-36. [PMID: 17383741 DOI: 10.1016/j.vetimm.2007.02.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Revised: 12/05/2006] [Accepted: 02/19/2007] [Indexed: 11/25/2022]
Abstract
Leishmania promastigotes interact with macrophages through the association of multiple membrane surface receptors. Macrophage complement receptor CR3 (CD11b/CD18 or Mac-1) has been implicated in the interaction of both human and murine macrophages with serum-opsonized promastigotes. The aim of this study was to determine CR3 expression in the livers and spleens of dogs naturally infected with Leishmania (Leishmania) chagasi. CR3 expression in liver was higher in asymptomatic than in symptomatic animals. Moreover, the hepatic parasitism load determined by immunocytochemical analysis was lower in parallel with higher numbers of granulomas. In contrast, in spleens, CR3 expression was higher in symptomatic animals than in asymptomatic ones. However, the tissue parasite load was greater in spleens of symptomatic dogs. There was a strict correlation between the parasite load and cellular CR3 expression in the spleens of dogs naturally infected with L. chagasi. CR3 macrophage integrins could be essential receptors for Leishmania survival. Considering that the symptomatic animals showed higher parasite loads and higher CD11b/CD18 expression in their spleens, we can conclude that these splenic cells (monocyte-macrophages) might serve to perpetuate intracellular infection.
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Affiliation(s)
- W G Lima
- Departamento de Patologia Geral ICB-UFMG, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, Brazil
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Melo MN, Castanho MARB. Omiganan interaction with bacterial membranes and cell wall models. Assigning a biological role to saturation. Biochimica et Biophysica Acta (BBA) - Biomembranes 2007; 1768:1277-90. [PMID: 17383609 DOI: 10.1016/j.bbamem.2007.02.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Revised: 01/28/2007] [Accepted: 02/02/2007] [Indexed: 11/18/2022]
Abstract
Omiganan pentahydrochloride (ILRWPWWPWRRK-NH(2).5Cl) is an antimicrobial peptide currently in phase III clinical trials. This study aims to unravel the mechanism of action of this drug at the membrane level and address the eventual protective role of peptidoglycan in cell walls. The interaction of omiganan pentahydrochloride with bacterial and mammalian membrane models - large unilamellar vesicles of different POPC:POPG proportions - was characterized by UV-Vis fluorescence spectroscopy. The molar ratio partition constants obtained for the two anionic bacterial membrane models were very high ((18.9+/-1.3)x10(3) and (43.5+/-8.7)x10(3)) and about one order of magnitude greater than for the neutral mammalian models ((3.7+/-0.4)x10(3) for 100% POPC bilayers). At low lipid:peptide ratios there were significant deviations from the usual hyperbolic-like partition behavior of peptide vesicle titration curves, especially for the most anionic systems. Membrane saturation can account for such observations and mathematical models were derived to further characterize the peptide-lipid interaction under those conditions; a possible relation between saturation and MIC was deduced; this was supported by differential quenching studies of peptide internalization. Interaction with the bacterial cell wall was assessed using Staphylococcus aureus peptidoglycan extracts as a model. A strong partition towards the peptidoglycan mesh was observed, but not as large as for the membrane models.
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Affiliation(s)
- Manuel Nuno Melo
- Centro de Química e Bioquímica, Faculdade de Ciências da UL, Campo Grande, C8, 1749-016 Lisboa, Portugal
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Abstract
In an attempt to isolate and characterize Toxoplasma gondii from the State of Minas Gerais, Brazil, musculature samples from 72 pigs, 25 dogs, 28 free-range chickens and 50 chickens produced in industrialized farms were collected. Antibodies to T. gondii have not been detected in pigs, but were found in nine (40.9 %) out of 22 dogs, and in 15 (53.6 %) of 28 free range chickens. T. gondii was not isolated from pigs and industrialized chickens, but from eight dogs and 11 free range chickens. In order to determine T. gondii virulence, female BALB/c mice were inoculated with 10(3), 10(2), 10(1) and 10(0) tachyzoites of the 19 isolates. The strains RH (virulent) and ME49 (non-virulent) were used as references. Isolates were divided into three groups according to the virulence phenotype: five isolates were classified into virulent in mice, one into non-virulent and 13 into intermediate virulent. Nested-PCR of T. gondii SAG2 locus amplified DNA from 21 out of 22 DNA samples directly extracted from heart of free range chickens. These samples were genotyped through a PCR-RFLP assay. Seventeen (80.9 %) were classified into type I; one (4.8 %) into type III and three (14.3 %) into type I or II.
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Affiliation(s)
- G P Brandão
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
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16
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Barros VC, Oliveira JS, Melo MN, Gontijo NF. Leishmania amazonensis: Chemotaxic and osmotaxic responses in promastigotes and their probable role in development in the phlebotomine gut. Exp Parasitol 2006; 112:152-7. [PMID: 16313904 DOI: 10.1016/j.exppara.2005.10.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Revised: 10/04/2005] [Accepted: 10/20/2005] [Indexed: 10/25/2022]
Abstract
Taxic responses may play a role in development of Leishmania in their phlebotomine sand fly vectors. They are possibly responsible for movement of the parasites towards the anterior regions of the gut, from where they would be transmitted to the vertebrate host. A methodology capable to distinguish chemotaxic from osmotaxic responses was described and used to characterise taxic responses in Leishmania promastigotes. These were able to respond to chemotaxic as well as to osmotaxic stimuli. Like bacteria, promastigotes were capable to undergo "adaptation," a phenomenon by which they stop responding to a continuos stimulus. A model capable to explain how a relatively small number of different receptors works to perceive gradients in chemotaxic responses was proposed. According to this model, these receptors possess low specificity and a wide range of affinities varying from high to low. A low specificity makes the same receptor able to bind to a large number of different but structurally related molecules and; a wide range of affinities (considering a population of receptors), implies that the number of receptors "occupied" by attractant molecules along a gradient would go growing step by step.
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Affiliation(s)
- V C Barros
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, MG, Brazil
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17
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Schettini DA, Costa Val AP, Souza LF, Demicheli C, Rocha OGF, Melo MN, Michalick MSM, Frézard F. Pharmacokinetic and parasitological evaluation of the bone marrow of dogs with visceral leishmaniasis submitted to multiple dose treatment with liposome-encapsulated meglumine antimoniate. Braz J Med Biol Res 2005; 38:1879-83. [PMID: 16302103 DOI: 10.1590/s0100-879x2005001200017] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of the present study was to evaluate the impact of a multiple dose regimen of a liposomal formulation of meglumine antimoniate (LMA) on the pharmacokinetics of antimony in the bone marrow of dogs with visceral leishmaniasis and on the ability of LMA to eliminate parasites from this tissue. Dogs naturally infected with Leishmania chagasi received 4 intravenous doses of either LMA (6.5 mg antimony/kg body weight, N = 9), or empty liposomes (at the same lipid dose as LMA, N = 9) at 4-day intervals. A third group of animals was untreated (N = 8). Before each administration and at different times after treatment, bone marrow was obtained and analyzed for antimony level (LMA group) by electrothermal atomic absorption spectrometry, and for the presence of Leishmania parasites (all groups). There was a significant increase of antimony concentration from 0.76 microg/kg wet organ (4 days after the first dose) to 2.07 microg/kg (4 days after the fourth dose) and a half-life of 4 days for antimony elimination from the bone marrow. Treatment with LMA significantly reduced the number of dogs positive for parasites (with at least one amastigote per 1000 host cells) compared to controls (positive dogs 30 days after treatment: 0 of 9 in the LMA group, 3 of 9 in the group treated with empty liposomes and 3 of 8 in the untreated group). However, complete elimination of parasites was not achieved. In conclusion, the present study showed that multiple dose treatment with LMA was effective in improving antimony levels in the bone marrow of dogs with visceral leishmaniasis and in reducing the number of positive animals, even though it was not sufficient to achieve complete elimination of parasites.
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Affiliation(s)
- D A Schettini
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 30123 Belo Horizonte, MG, Brazil
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18
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Oliveira MR, Tafuri WL, Afonso LCC, Oliveira MAP, Nicoli JR, Vieira EC, Scott P, Melo MN, Vieira LQ. Germ-free mice produce high levels of interferon-gamma in response to infection with Leishmania major but fail to heal lesions. Parasitology 2005; 131:477-88. [PMID: 16174412 DOI: 10.1017/s0031182005008073] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Revised: 04/15/2005] [Accepted: 04/21/2005] [Indexed: 11/05/2022]
Abstract
In order to investigate the importance of the host microbiota on differentiation of T cell subsets in response to infection, Swiss/NIH germ-free mice and conventional (microbiota-bearing) mice were infected with Leishmania major, and lesion development, parasite loads, and cytokine production were assessed. Germ-free mice failed to heal lesions and presented a higher number of parasites at the site of infection than their conventional counterparts. In addition, histopathological analysis indicated a higher density of parasitized macrophages in lesions from germ-free mice than in conventional mice. The initial production of interleukin (IL)-12 and interferon-gamma (IFN-gamma) in germ-free mice was comparable to the conventional controls. Also, germ-free mice produced elevated levels of IFN-gamma and lower levels of IL-4 throughout the course of infection, suggesting the development of a Th1 response. Macrophages from germ-free mice exposed to IFN-gamma and infected with amastigotes in vitro were not as efficient at killing parasites as macrophages from conventional animals. These observations indicate that the microbiota is not essential for the development of Th1 immune responses, but seems to be important for macrophage activation.
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Affiliation(s)
- M R Oliveira
- Departamento de Parasitologia, ICB, Universidade Federal de Minas Gerais, CP486, 30161-970, Belo Horizonte, MG, Brazil
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19
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Schettini DA, Costa Val AP, Souza LF, Demicheli C, Rocha OGF, Melo MN, Michalick MSM, Frézard F. Distribution of liposome-encapsulated antimony in dogs. Braz J Med Biol Res 2003; 36:269-72. [PMID: 12563530 DOI: 10.1590/s0100-879x2003000200015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The achievement of complete cure in dogs with visceral leishmaniasis is currently a great challenge, since dogs are the main reservoir for the transmission of visceral leishmaniasis to humans and they respond poorly to conventional treatment with pentavalent antimonials. In order to improve the efficacy of treatment, we developed a novel formulation for meglumine antimoniate based on the encapsulation of this drug in freeze-dried liposomes (LMA). The aim of the present study was to evaluate the biodistribution of antimony (Sb) in dogs following a single intravenous bolus injection of LMA. Four healthy male mongrel dogs received LMA at 3.8 mg Sb/kg body weight and were sacrificed 3, 48 and 96 h and 7 days later. Antimony was determined in the blood, liver, spleen and bone marrow. In the bone marrow, the highest Sb concentration was observed at 3 h (2.8 microg/g wet weight) whereas in the liver and spleen it was demonstrated at 48 h (43.6 and 102.4 microg/g, respectively). In these organs, Sb concentrations decreased gradually and reached levels of 19.1 microg/g (liver), 28.1 microg/g (spleen) and 0.2 microg/g (bone marrow) after 7 days. Our data suggest that the critical organ for the treatment with LMA could be the bone marrow, since it has low Sb levels and, presumably, high rates of Sb elimination. A multiple dose treatment with LMA seems to be necessary for complete elimination of parasites from bone marrow in dogs with visceral leishmaniasis.
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Affiliation(s)
- D A Schettini
- Departamentos de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
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20
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Ishikawa EAY, Silveira FT, Magalhães ALP, Guerra júnior RB, Melo MN, Gomes R, Silveira TGV, Shaw JJ. Genetic variation in populations of Leishmania species in Brazil. Trans R Soc Trop Med Hyg 2002; 96 Suppl 1:S111-21. [PMID: 12055823 DOI: 10.1016/s0035-9203(02)90061-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The population structure of strains of Leishmania (Viannia) braziliensis sensu lato from Pará State and Paraná State in Brazil, of L. (V.) shawi and L. (Leishmania) amazonensis from Pará State, and the relationships of type strains of the subgenera L. (Viannia) and L. (Leishmania) were examined by the random-amplified polymorphic deoxyribonucleic acid (RAPD) technique. Four different primers (M13-40, QG1, L15996 and delta gt11R) were used. The bands were analysed using the neighbor-joining (NJ) and unweighted pair-group method with arithmetic averages (UPGMA) algorithms of the MEGA package. The topology of the NJ and UPGMA trees was very similar but they were not always identical. Both trees differentiated the standard strains of the different species. Strains from the same location were grouped together only in the UPGMA phenogram of the M13-40 primer. L. (V.) braziliensis isolates from Paraná State were genetically closer to those from Paragominas, Pará State than to those from the Amazonian regions of Carajás in Pará State and Peru. The relationship was not dependent on geographical distance. It is postulated that the groups arose from different origins, in which the Amazonian stocks were related to Psychodopygus sand flies while the Paraná strains originated from a gene pool transmitted by Lutzomyia sand flies such as Lutzomyia (Nyssomyia) whitmani. Transmission by Ps. complexus in Paragominas is considered to be a secondary adaptation from the Lutzomyia leishmanial gene pool. Although the vectors of L. (V.) braziliensis are poorly known in the Amazon region, there is strong evidence that the major vectors are all Psychodopygus spp. There was a high degree of genetic variability amongst the L. (V.) shawi strains and there was no clear grouping according to the strains' origins. The genetic variability amongst L. (L.) amazonensis strains from the same locations was much lower but they formed 2 groups which coincided with their origin. Our results support the clonal population structure of Leishmania isolates and suggest that their distribution is related to the origin of the gene pool as well as to present vector and reservoir movements.
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Affiliation(s)
- E A Y Ishikawa
- Divisão de Parasitologia, Instituto Evandro Chagas, Fundação Nacional de Saúde, Belém, Pará, Brazil
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21
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Gontijo CMF, da Silva ES, de Fuccio MB, de Sousa MCA, Pacheco RS, Dias ES, Andrade Filho JD, Brazil RP, Melo MN. Epidemiological studies of an outbreak of cutaneous leishmaniasis in the Rio Jequitinhonha Valley, Minas Gerais, Brazil. Acta Trop 2002; 81:143-50. [PMID: 11801221 DOI: 10.1016/s0001-706x(01)00205-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We detected an outbreak of American cutaneous leishmaniasis in the Jequitinhonha River Valley, Minas Gerais, Brazil. Clinical and epidemiological aspects were studied for a period of two years. Data include results of physical examinations, Montenegro skin test and serology. In total 72 of the 299 individuals evaluated presented active lesions. Only one case out of these 72 patients showed the mucosal form of the disease. The precarious sanitary conditions, low educational level and low income found in the population studied demonstrated that, as with the other parasitic diseases, cutaneous leishmaniasis occurs with greater frequency in needy populations. A canine serological survey detected 20.3% (30/148) of dogs reactive to the Leishmania antigen. Lutzomyia intermedia was the predominant phlebotomine species and the majority of the specimens (84.9%) were captured in the peridomicile. Four samples from human and three from canine cases were isolated and characterised by PCR and isoenzymes as being Leishmania (Viannia) braziliensis. The peridomiciliary nature of the disease is discussed.
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Affiliation(s)
- C M F Gontijo
- Laboratório de Leishmanioses, Centro de Pesquisas René Rachou/FIOCRUZ, Fundação Oswaldo Cruz. Av. Augusto de Lima, 1715, Belo Horizonte, MG 30190-002, Brazil.
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22
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Costa CA, Gomes RF, Melo MN, Ribeiro MF. Eimeria parasites of domestic fowl: genetic relationships of different isolates estimated from random amplified polymorphic DNA. Parasitol Res 2001; 87:459-66. [PMID: 11411945 DOI: 10.1007/s004360000369] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Genetic relationships between Eimeria parasites of domestic fowl, including three isolates of E. acervulina, one of E. maxima, four of E. mitis, six of E. praecox, one of E. tenella, and two of uncertain identity, were analyzed by random amplified polymorphic DNA (RAPD) and the unweighted pair-group method with arithmetic mean, using 12 primers. Each primer amplified 4-34 DNA fragments/isolate. The similarity coefficients and phenograms were calculated from RAPD products with 230-2,000 bp in silver-stained polyacrylamide gels. Some primers generated RAPD markers which were species-specific for E. acervulina, E. mitis, and E. praecox. The phenograms revealed six clusters, each corresponding to an individual Eimeria species. The pBP and pBP2 isolates, of uncertain identity, clustered with the E. acervulina isolates (100% bootstrap). The intraspecific relationships showed certain degree of genetic isolation of the Eimeria populations, and it was associated with broiler house and with geographic separation.
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Affiliation(s)
- C A Costa
- EMBRAPA Suínos e Aves, Santa Catarina, Brazil
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23
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Abstract
This report describes a remarkable histopathological presentation of a symptomatic dog naturally infected with Leishmania (Leishmania) chagasi from Brazil. An intense inflammatory granulomatous reaction was observed in the liver and spleen associated with hypertrophy and hyperplasia of the mononuclear system (the classical histopathological picture of the disease). In addition, a spectrum of vascular lesions was observed in many organs. However, we did not find parasites (amastigotes of Leishmania) in any skin fragments of the ear, nose and or abdominal tissue. In fact, this animal had severe clinical signs, showed parasites in many organs, but no parasites in the skin. It appears that the presence or absence of parasites in the skin is not a good indicator of parasites in other organs or vice versa.
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Affiliation(s)
- W L Tafuri
- Departamento de Patologia Geral, Instituto de Ciencias Biológicas (ICB), Universidade Federal de Minas Gerais (UFMG), MG, Belo Horizonte, Brazil.
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24
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Melo MN, Williams P, Tafuri WL. Influence of lysates of the salivary glands of Lutzomyia longipalpis on the development of a Leishmania-major-like parasite in the skin of the golden hamster. Ann Trop Med Parasitol 2001; 95:59-68. [PMID: 11235554 DOI: 10.1080/00034980020035924] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Twelve years ago, some mice inoculated with Leishmania major were found to develop larger lesions, containing more amastigotes, if the inoculum used to infect them contained a lysate of salivary glands from Lutzomyia longipalpis than if no lysate was included. In the present study, outbred golden hamsters (Mesocricetus auratus) were each inoculated in a footpad with 10(4), 10(5), 10(6) or 10(7) stationary-phase promastigotes of a Leishmania-major-like parasite (MHOM/BR/71/BH49). Some of the inocula used each contained a lysate of the salivary glands from a laboratory-reared, female Lu. longipalpis. Only the hamsters inoculated with 10(7) promastigotes each developed macroscopic cutaneous lesions (all 10 co-inoculated with lysate but only two of the 10 co-inoculated with diluent). Each of the lesions developed into cutaneous nodule affecting the dermis and underlying subcutaneous tissue of the inoculated footpad, with, histologically, an intensive, diffuse and productive, inflammatory reaction. There were no apparent differences between the lesions of hamsters infected with inocula containing salivary-gland lysate and those seen in the animals infected with lysate-free inocula. Future studies will follow the histological changes at the sites of Lu. longipalpis bites.
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Affiliation(s)
- M N Melo
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil.
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25
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Abstract
This article describes a sensitive, cheap, and easy method for assaying chemotaxic responses of Leishmania promastigotes. A gradient of the substance to be assayed was produced inside a series of commercially available capillary tubes submerged in a promastigote suspension. After an incubation period, the attractiveness of the substance under test was measured by counting the number of parasites in the capillaries in a Neubauer chamber. Different responses were detected in two strains of Leishmania amazonensis and one strain of L. chagasi after standardization of the method to assay attraction to carbohydrates. Very different responses were obtained when the test was performed using promastigotes of the same strain in two different physiological states (log and stationary phase). The stationary phase cells showed an enhanced chemotaxic capability, which can be explained by the fact that the metacyclic forms commonest in stationary phase cultures have greater mobility than other promastigotes. This method will permit studies to be made of the attractive response to different substances in Leishmania species and other trypanosomatids and facilitate characterization of the potential receptors involved in the chemotaxic response. An adaptation of the method to assay the response to repellent substances is also provided.
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Affiliation(s)
- J S Oliveira
- Departamento de Parasitologia, Instituto de Ciéncias Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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26
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Tafuri WL, Melo MN, Paiva MC, Mosser DM, Tafuri WL. Kinetics of an experimental inflammatory reaction induced by Leishmania major during the implantation of paraffin tablets in mice. Virchows Arch 2000; 437:429-35. [PMID: 11097369 DOI: 10.1007/s004280000231] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In leishmaniasis, macrophages play important but potentially divergent roles. They act as the host cell in which the parasite may reside and replicate, and, at the same time, they act as an effector cell with the potential to eliminate the parasite. In this work, we experimentally induced an inflammatory model that provokes a continued recruitment of the monocytes to the site of inflammation. This model was carried out by means of implanting paraffin tablets under the skin of Balb/c or C57BL/6 mice. Mice were then infected with Leishmania major to determine how the monocyte inflammatory response to paraffin could influence the course of infection with L. major. Mice were sacrificed 15, 21, 30, and 45 days after infection, and skin and inflammatory capsule were collected for histopathology. At 15 days and 21 days, the lesions induced by L. major in combination with paraffin contained markedly increased numbers of parasites relative to lesions in parallel control animals infected with L. major (without paraffin). Both Balb/c and C57BL/6 mice exhibited high parasite numbers in their lesions. The intense parasite burden observed following paraffin implantation would suggest that the monocytes-macrophages that are recruited to the lesion are acting more as a host cell permitting parasite growth than as an effector cell capable of eliminating L. major. At later times, the two strains of mice stratified according to their genetic susceptibility/resistance profiles. Susceptible Balb/c mice continue to have large parasite burdens, whereas the resistant C56BL/6 mice begin to control parasite numbers. This later observation indicates that the genetic difference between susceptible and resistant strains is not due to differences in monocyte recruitment and cannot be reversed through the altering of monocyte inflammation.
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Affiliation(s)
- W L Tafuri
- Departamento de Patologia Geral, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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27
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Gomes MA, Melo MN, Macedo AM, Pena GP, Caliari MV, Silva EF. Characterization of Entamoeba histolytica and Entamoeba dispar by biological, biochemical, and molecular parameters. Arch Med Res 2000; 31:S249-50. [PMID: 11070303 DOI: 10.1016/s0188-4409(00)00213-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- M A Gomes
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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28
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Abstract
Genetic variability in Entamoeba histolytica was analyzed by random amplified polymorphic DNA (RAPD) using ten arbitrary primers. Due to intrinsic characteristics of the RAPD technique only axenic samples were analyzed. since the presence of any microorganism in the cultures interfered in the DNA profile by generating RAPDs not pertaining to E. histolytica. The RAPD profiles of E. histolytica samples isolated from patients with different clinical manifestations from different regions of the Americas shared about 70% of the bands produced. These profiles were compared to those obtained for E. moshkorskii, and E. invadens. The combined data for the ten primers were used in the phenetic analysis of all the isolates studied by using the Dice similarity coefficient as the genetic distance measure between the samples. Three distinct groups could be separated by phenon line: one including E. moshkovskii samples, which shared > 90% of the RAPDs produced by the different primers; one consisting solely of E. invadens; and a third comprising samples of E. histolytica, which showed considerable intraspecific variability.
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Affiliation(s)
- M A Gomes
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade fedral de Minas Gerais, Belo Horizonte, Brazil.
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29
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de Oliveira MR, Tafuri WL, Nicoli JR, Vieira EC, Melo MN, Vieira LQ. Influence of microbiota in experimental cutaneous leishmaniasis in Swiss mice. Rev Inst Med Trop Sao Paulo 1999; 41:87-94. [PMID: 10413955 DOI: 10.1590/s0036-46651999000200005] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Infection of Swiss/NIH mice with Leishmania major was compared with infection in isogenic resistant C57BL/6 and susceptible BALB/c mice. Swiss/NIH mice showed self-controlled lesions in the injected foot pad. The production of high levels of interferon-gamma (IFN-gamma) and low levels of interleukin-4 (IL-4) by cells from these animals suggests that they mount a Th1-type immune response. The importance of the indigenous microbiota on the development of murine leishmaniasis was investigated by infecting germfree Swiss/NIH in the hind footpad with L. major and conventionalizing after 3 weeks of infection. Lesions from conventionalized Swiss/NIH mice were significantly larger than conventional mice. Histopathological analysis of lesions from conventionalized animals showed abscesses of variable shapes and sizes and high numbers of parasitized macrophages. In the lesions from conventional mice, besides the absence of abscess formation, parasites were rarely observed. On the other hand, cells from conventional and conventionalized mice produced similar Th1-type response characterized by high levels of IFN-gamma and low levels of IL-4. In this study, we demonstrated that Swiss/NIH mice are resistant to L. major infection and that the absence of the normal microbiota at the beginning of infection significantly influenced the lesion size and the inflammatory response at the site of infection.
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Affiliation(s)
- M R de Oliveira
- Departamento de Bioquímica, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
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30
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Gontijo NF, Almeida-Silva S, Costa FF, Mares-Guia ML, Williams P, Melo MN. Lutzomyia longipalpis: pH in the gut, digestive glycosidases, and some speculations upon Leishmania development. Exp Parasitol 1998; 90:212-9. [PMID: 9806865 DOI: 10.1006/expr.1998.4336] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Screening for digestive glycosidases in different parts of the gut and associated organs of Lutzomyia longipalpis is reported. Searches for the enzymes were made in blood-fed and non-blood-fed females and the enzymes were characterized as soluble or membrane-bound molecules. A total of four different activities were detected, corresponding to the following specificities: an alpha-glucosidase, an N-acetyl-beta-d-glucosaminidase, an N-acetyl-beta-d-galactosaminidase, and an alpha-l-fucosidase. Their possible role and importance for Leishmania development are discussed and the alpha-glucosidase enzyme was partially characterized. The pH inside the gut of non-blood-fed phlebotomines was measured with pH indicator dyes. The pH ranges obtained for crop, midgut, and hindgut were, respectively, higher than pH 6, pH 6, and lower than pH 6. A hypothesis concerning these data and Leishmania development is proposed.
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Affiliation(s)
- N F Gontijo
- Departamento de Parasitologia, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais-UFMG, Caixa Postal 486, Minas Gerais, Belo Horizonte, CEP 31 270-901, Brazil.
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31
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Noronha FS, Nunes AC, Souza KT, Melo MN, Ramalho-Pinto FJ. Differential sensitivity of New World Leishmania spp. promastigotes to complement-mediated lysis: correlation with the expression of three parasite polypeptides. Acta Trop 1998; 69:17-29. [PMID: 9588238 DOI: 10.1016/s0001-706x(97)00108-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
American tegumentary leishmaniasis is caused by Leishmania of the subgenera Leishmania and Viannia. In this paper, we demonstrate that promastigotes of these two subgenera display distinct characteristic patterns of complement sensitivity during growth in vitro. Using fresh normal human serum in lytic assays, we show that while promastigotes of two species of the subgenus Leishmania differentiate into forms that are more resistant to the lytic action of complement, promastigotes of three species of the subgenus Viannia remain sensitive to complement mediated lysis during all stages of their growth in vitro. Complement resistance of the subgenus Leishmania is temporary, reaching its peak at the beginning of the stationary phase of growth, and decreasing thereafter. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) we detected in L. amazonensis (subgenus Leishmania), but not in L. guyanensis (subgenus Viannia), three polypeptides whose expression parallels the resistance of promastigotes to complement-mediated lysis.
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Affiliation(s)
- F S Noronha
- Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte MG, Brazil
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32
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Gomes MA, Melo MN, Pesquero JL, Silva EF. Characterization for virulence of an axenic strain of Entamoeba histolytica: evidence for overexpression of two proteins. Arch Med Res 1998; 28:489-92. [PMID: 9428571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The pattern of protein from membrane and crude homogenate of Entamoeba histolytica strain 462 axenically cultivated (462ac) and submitted to hamster liver passage (462hp) was obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The substrains 462ac and 462hp were compared by zymodeme analysis, erythrophagocytosis, cytopathic effect upon mammalian cells and the capability to induce abscess in hamster liver. The results showed no differences for erythrophagocytosis, cytopathic effect or zymodene for substrains 462ac and 462hp. A type II pathogenic zymodene was observed. Substrain 462ac did not induce liver abscess, but 462hp induced abscesses in 70% of the inoculated animals. The pattern of proteins from plasma membrane and crude homogenate were different. One protein of approximately 45kDa and another of 23 kDa showed at no detectable levels in the membrane of 462ac. A third component of approximately 90 kDa showed more intensively expressed in the 462ac.
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Affiliation(s)
- M A Gomes
- Department of Parasitology, Institute of Biological Services, Federal University of Minas Gerais, Belo Horizonte, Brazil
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33
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Gomes MA, Silva EF, Macedo AM, Vago AR, Melo MN. LSSP-PCR for characterization of strains of Entamoeba histolytica isolated in Brazil. Parasitology 1997; 114 ( Pt 6):517-20. [PMID: 9172422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Strains of Entamoeba histolytica isolated in Brazil were characterized using the Low-Stringency Single Specific Primer PCR (LSSP-PCR), that detects single or multiple mutations in gene size DNA fragments. Using this technique, a 482-bp genomic DNA fragment from a structural gene in 8 strains and 2 clones of E. histolytica, isolated from symptomatic and asymptomatic patients in Brazil, including pathogenic and non-pathogenic zymodemes were studied. The results obtained indicate that LSSP-PCR is a valuable method for differentiating strains of E. histolytica. Moreover, the results are consistent with the concept that pathogenic and non-pathogenic strains of E. histolytica may represent distinct species or subspecies and are in accord with phenotypically characteristic isoenzyme patterns.
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Affiliation(s)
- M A Gomes
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Brasil
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34
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Abstract
Differences in virulence of strains of Entamoeba histolytica have long been detected by various experimental assays, both in vivo and in vitro. Discrepancies in the strains characterization have been arisen when different biological assays are compared. In order to evaluate different parameters of virulence in the strains characterization, five strains of E. histolytica, kept under axenic culture, were characterized in respect to their, capability to induce hamster liver abscess, erythrophagocytosis rate and cytopathic effect upon VERO cells. It was found significant correlation between in vitro biological assays, but not between in vivo and in vitro assays. Good correlation was found between cytopathic effect and the mean number of uptaken erythrocytes, but not with percentage of phagocytic amoebae, showing that great variability can be observed in the same assay, according to the variable chosen. It was not possible to correlate isoenzyme and restriction fragment pattern with virulence indexes since all studied strains presented pathogenic patterns. The discordant results observed in different virulence assays suggests that virulence itself may not the directly assessed. What is in fact assessed are different biological characteristics or functions of the parasite more than virulence itself. These characteristics or functions may be related or not with pathogenic mechanisms occurring in the development of invasive amoebic disease.
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Affiliation(s)
- M A Gomes
- Dep. Parasitologia, ICB/UFMG, Belo Horizonte, MG, Brasil
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35
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Fernandes AP, Herrera EC, Mayrink W, Gazzinelli RT, Liu WY, de Costa CA, Tavares CA, Melo MN, Michalick MS, Gentz R, Nascimento E. Immune responses induced by a Leishmania (Leishmania) amazonensis recombinant antigen in mice and lymphocytes from vaccinated subjects. Rev Inst Med Trop Sao Paulo 1997; 39:71-8. [PMID: 9394518 DOI: 10.1590/s0036-46651997000200002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In the search for Leishmania recombinant antigens that can be used as a vaccine against American Cutaneous Leishmaniasis, we identified a Leishmania (Leishmania) amazonensis recombinant protein of 33 kD (Larp33) which is recognized by antibodies and peripheral blood leukocytes (PBL) from subjects vaccinated with Leishvacin, Larp33 was expressed in Escherichia coli after cloning of a 2.2 kb Sau3 digested genomic fragment of L. (L.) amazonensis into the pDS56-6 His vector. Immunoblotting analysis indicated that Larp33 corresponds to an approximately 40-kD native protein expressed in promastigotes of L. (L.) amazonensis and L. (Viannia) braziliensis. Northern blots of total RNA also demonstrated that the gene coding for this protein is expressed in promastigotes of the major lineages of Leishmania causing American Cutaneous Leishmaniasis. Larp33 induced partial protection in susceptible mouse strains (BALB/c and C57BL/10) against L. (L.) amazonensis after vaccination using Bacille Calmette-Guerin (BCG) as adjuvant. In vitro stimulation of splenocytes from BALB/c protected mice with Larp33 elicited the secretion of IL-2 and IFN-gamma, suggesting that a Th1 cell-mediated protective response is associated with the resistance observed in these mice. As revealed by its immunogenic and antigenic properties, this novel recombinant antigen is a suitable candidate to compose a vaccine against cutaneous leishmaniasis.
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Affiliation(s)
- A P Fernandes
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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36
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Gontijo NF, Melo MN, Riani EB, Almeida-Silva S, Mares-Guia ML. Glycosidases in Leishmania and their importance for Leishmania in phlebotomine sandflies with special reference to purification and characterization of a sucrase. Exp Parasitol 1996; 83:117-24. [PMID: 8654540 DOI: 10.1006/expr.1996.0055] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Culture forms of Leishmania (Leishmania) amazonensis (IFLA/BR/67/PH8) produce an extracellular enzyme that hydrolyzes sucrose molecules into their component monosaccharides. This is important because phlebotomine sand flies, the invertebrate hosts of Leishmania, ingest plant sap or aphid and coccid honeydew rich in sucrose between blood meals and Leishmania promastigotes cannot uptake sucrose. The sucrase was purified and characterized; its molecular weight, estimated by gel filtration chromatography and SDS-PAGE electrophoresis, was about 73 kDa. K(m) and V(max) measured with sucrose as substrate were respectively 4.4 mM and 6.9 mumole glucose.min-1 (mg sucrase)-1, with maximum pH activity at pH 5.5. A series of natural and p-nitrophenyl-derived substrates were assayed, characterizing the enzyme as a highly specific beta-D-fructofuranoside fructohydrolase. When 11 species of Leishmania and 7 genera of trypanosomatids were screened, only the species of the genus Trypanosoma did not produce an enzyme with saccharolytic activity. These data are in agreement with the fact that the latter vectors do not acquire sucrose or raffinose in their meals. Searching for glycolytic enzymes other than sucrase, we found an N-acetyl-beta-D-galactosaminolytic activity. This N-acetyl-galactosaminidase, here described for the first time, might have a role in peritrophic membrane disruption. The importance of sucrase and N-acetyl-beta-D-galactosaminidase in the Leishmania life cycle is discussed.
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Affiliation(s)
- N F Gontijo
- Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Brazil
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37
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Gomes RF, Macedo AM, Pena SD, Melo MN. Leishmania (Viannia) braziliensis: genetic relationships between strains isolated from different areas of Brazil as revealed by DNA fingerprinting and RAPD. Exp Parasitol 1995; 80:681-7. [PMID: 7758549 DOI: 10.1006/expr.1995.1084] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Leishmania (Viannia) braziliensis isolates from two different geographic areas in Brazil were studied by DNA fingerprinting with the 33.15 multilocal probe and PCR with arbitrary primers (random amplification of polymorphic DNA-RAPD). The genetic distance of strains was measured by band sharing. The results showed that the strains isolated in Minas Gerais, southeastern Brazil, are very different from those isolated in Pará, northern Brazil. Strains from Minas Gerais constituted a relatively homogeneous group, presenting DNA fingerprint patterns with 76% of shared bands and RAPD profiles with 93% of shared bands. In contrast, strains from Pará showed higher genetic variability, with only 17 and 45% of shared bands in DNA fingerprint and RAPD patterns, respectively. This study suggests that genetic differences between L. braziliensis from both areas might have an epidemiological significance.
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Affiliation(s)
- R F Gomes
- Departamento de Parasitologia, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, Brazil
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38
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Mayrink W, Magalhaes PA, Michalick MS, da Costa CA, Lima ADO, Melo MN, Toledo VP, Nascimento E, Dias M, Genaro O. Immunotherapy as a treatment of American cutaneous leishmaniasis: preliminary studies in Brazil. Parassitologia 1992; 34:159-65. [PMID: 1339971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A prophylactic vaccine composed of killed promastigotes of five stocks of Leishmania was tested as an immunotherapeutic agent against American cutaneous leishmaniasis (ACL). The agent was administered by deep intramuscular injection daily for 10 days, followed by a 10-day interval. Out of 62 patients so treated, 47 (76%) were considered clinically cured; 41 required 2-10 treatment courses and the other six 11-19 courses. None of the patients treated by immunotherapy displayed adverse side-effects. Immunotherapy proved to be effective in the treatment of single cutaneous lesions, multiple cutaneous lesions and in cases of mucocutaneous leishmaniasis. In comparison with chemotherapy (Glucantime), immunotherapy is less efficient and more prolonged but can be safely used when antimonials are contra-indicated or are found to be ineffective. Consideration is given to the treatment of victims of ACL living in rural areas remote from a medical centre.
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Affiliation(s)
- W Mayrink
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
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39
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Macedo AM, Melo MN, Gomes RF, Pena SD. DNA fingerprints: a tool for identification and determination of the relationships between species and strains of Leishmania. Mol Biochem Parasitol 1992; 53:63-70. [PMID: 1501645 DOI: 10.1016/0166-6851(92)90007-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Using nonradioactive hybridization, the multilocal probes 33.15, F10 and (CAC)5 were shown to recognize multiple minisatellite regions in nuclear DNA of Leishmania, producing on Southern blots complex banding patterns typical of DNA fingerprints. We used the 33.15 probe to study 14 different strains belonging to 6 different species from both the sub-genus Viannia and the Leishmania mexicana complex of the sub-genus Leishmania. Distinct DNA fingerprints were obtained for each strain, permitting their identification. On the other hand, each strain showed little or no clonal variation. The information from the fingerprinting maps could be used for constructing phenograms and cladograms of the species and strains of Leishmania.
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Affiliation(s)
- A M Macedo
- Department of Biochemistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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40
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da Costa CA, Genaro O, de Lana M, Magalhães PA, Dias M, Michalick MS, Melo MN, da Costa RT, Magalhães-Rocha NM, Mayrink W. [Canine visceral leishmaniasis: evaluation of the serologic method used in epidemiologic studies]. Rev Soc Bras Med Trop 1991; 24:21-5. [PMID: 1815283 DOI: 10.1590/s0037-86821991000100004] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A comparative study was made of eluates of the blood of dogs experimentally infected with different trypanosomatids. Using antigens prepared from promastigotes of Leishmania mexicana, L. braziliensis and L. chagasi, assessments were made by the indirect immunofluorescence test. The results showed a sensitivity of 87.5% in the diagnosis of canine visceral leishmaniasis, independent of antigen used. Cross-reactions occurred in 75% of cases of cutaneous leishmaniasis and 83.3% of dogs with chagas' disease. An epidemiological survey in an area of leishmaniasis confirmed that immunofluorescence tests on eluates of dogs' blood give cross-reactions between L. braziliensis and L. chagasi. The results suggest that such testing could be useful in public health campaigns but attention is drawn to the fact that the level of positive reactions cannot be used as an indicator of the prevalence of canine kala-azar.
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Affiliation(s)
- C A da Costa
- Departamentos de Análises Clínicas e Toxicológicas da Faculdade de Farmácia e de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte
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41
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da Silva AL, Williams P, Melo MN, Mayrink W. Distinctions between promastigotes of Leishmania species developing in the digestive tract of laboratory reared Lutzomyia longipalpis. Mem Inst Oswaldo Cruz 1991; 86:67-71. [PMID: 1842403 DOI: 10.1590/s0074-02761991000100011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Female Lutzomyia longipalpis were exposed to infection by three different species/strains of Leishmania. When the insects were dissected four days after exposure, stained preparations were made of the flagellates contained in the digestive tract. Using traditional morphometric methods, L. amazonensis, L. guyanensis and an unnamed species of the mexicana complex could be distinguished from one another.
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Affiliation(s)
- A L da Silva
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
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42
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Da Silva AL, Williams P, Melo MN, Mayrink W. Susceptibility of laboratory-reared female Lutzomyia longipalpis (Lutz & Neiva, 1912) to infection by different species and strains of Leishmania Ross, 1903. Mem Inst Oswaldo Cruz 1990; 85:453-8. [PMID: 2152197 DOI: 10.1590/s0074-02761990000400010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A study was undertaken to compare the susceptibility of laboratory-reared female Lutzomyia longipalpis to infection by different species or strains of New World Leishmania. The sand flies proved to be highly susceptible to infection by a strain of Le. guyanensis, with flagellates developing in all (18/18) of the specimens examined. A lower infection rate of 37% (10/27) was recorded in flies exposed to infection by a strain of Le. amazonensis. Flagellates developed in 13% (6/46) of the sand flies that blood fed on dogs in the early stage of experimental infection with an old laboratory strain of Le. chagasi. In contrast, promastigotes did not develop in sand flies that blood fed on dogs with naturally acquired Le. chagasi. The naturally infected dogs were in an advanced stage of disease. Flagellates developed in 9% (3/32) of the sand flies that blood fed on lesions of hamsters infected with a strain of Le. braziliensis and in 9% (3/34) of those that fed on hamsters with lesions due to a parasite of the mexicana complex (strain MHOM/BR/73/BH121). Sand flies did not develop flagellate infections after blood feeding on hamsters bearing lesions induced by strain MHOM/BR/71/BR49. Factors influencing the susceptibility of Lu. longipalpis to infection by New World species of Leishmania are discussed.
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Affiliation(s)
- A L Da Silva
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
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43
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Nascimento E, Mayrink W, da Costa CA, Michalick MS, Melo MN, Barros GC, Dias M, Antunes CM, Lima MS, Taboada DC. Vaccination of humans against cutaneous leishmaniasis: cellular and humoral immune responses. Infect Immun 1990; 58:2198-203. [PMID: 2365458 PMCID: PMC258797 DOI: 10.1128/iai.58.7.2198-2203.1990] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Brazilian army conscripts were vaccinated against American cutaneous leishmaniasis by using nonliving polyvalent promastigote Leish vaccine 5 or Leish vaccine 6 (vaccines with five or six Leishmania stocks) with or without Corynebacterium parvum. No statistically significant differences in lymphocyte stimulation indices were found between vaccinated groups with or without C. parvum, but lymphocyte stimulation indices of all vaccinees were significantly higher (P less than 0.001) than those of the placebo group. A correlation of 90% was found between positive skin test results and positive lymphocyte stimulation indices. Eight major antigens with estimated molecular masses of 13.5, 25, 40, 63, 73, 85, 97, and 160 kilodaltons were recognized by Leish vaccine 5 sera. Our finding also demonstrated the predominance of immunoglobulin M antibody in sera of vaccinated subjects and that a component of Leish vaccine 5, gp63, was immunogenic in humans both at the T-cell level and at the antibody level.
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Affiliation(s)
- E Nascimento
- Institute of Biological Science, Federal University of Minas Gerais State, Belo Horizonte-MG, Brazil
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44
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Mayrink W, Genaro O, Dias M, da Costa CA, Michalick MS, Melo MN, Williams P, da Costa RT, Nascimento E, Oliveira Lima A. Vaccination of dogs against Leishmania (Viannia) braziliensis. Rev Inst Med Trop Sao Paulo 1990; 32:67-9. [PMID: 2259836 DOI: 10.1590/s0036-46651990000100012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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45
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Mayrink W, Schettini AP, Williams P, Raso P, Magalhães PA, Lima ADO, Melo MN, da Costa CA, Genaro O, Dias M. Histological observations on Montenegro's reaction in man. Rev Inst Med Trop Sao Paulo 1989; 31:256-61. [PMID: 2626646 DOI: 10.1590/s0036-46651989000400008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The Montenegro skin test is widely used as a diagnostic method for American cutaneous leishmaniasis (ACL) but little is known about the histological changes that occur in the skin after administration of the antigen. This report is based on histological studies of biopsied material obtained, from inoculation sites, 48 hours after individuals had been given intradermal injections with a standardized Montenegro antigen. The material examined was obtained from four distinctly different test groups: naturally infected patients with parasitologically proved ACL and with positive Montenegro's reaction; individuals without previous history of ACL and not previously tested with Montenegro antigen; participants in anti-ACL vaccine trials who developed positive reactions to Montenegro antigen after vaccination; other participants in vaccine trials who had negative Montenegro responses after vaccination or had served as controls in the trials. The histological pictures of each group are described and discussed. Histologically, the reactions of vaccinated individuals were indistinguishable from those with naturally acquired infections.
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46
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Tafuri WL, Michalick MS, Dias M, Genaro O, Leite VH, Barbosa AJ, Bambirra EA, da Costa CA, Melo MN, Mayrink W. [Optical and electron microscopic study of the kidney of dogs naturally and experimentally infected with Leishmania (Leishmania) chagasi]. Rev Inst Med Trop Sao Paulo 1989; 31:139-45. [PMID: 2617010 DOI: 10.1590/s0036-46651989000300002] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Two naturally infected dogs (male and female) from Teófilo Otoni (MG-Brazil) were maintained for 18 months in our laboratory. Two other dogs, two months old males were infected with 1 x 10(6) promastigotes of MHO/BR/70/BH46 Leishmania (Leishmania) chagasi strain, endovenous route, and autopsied after 10 months and two years. The main findings concerning the kidney were: (1) focal or diffuse mesangial glomerulonephritis with proliferative and enlargement of mesangial cells; (2) increase in thickness of basement membrane with electron-dense deposits; (3) chronic interstitial nephritis with intense exudation of plasmocytes; (4) cloud swelling of renal tubules. The authors discuss the probable pathogenetic mechanisms.
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47
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Melo MN, Williams P, Rocha NM, Babá EH, Mayrink W, Michalick MS, da Costa CA, Dias M, Magalhães PA. The change of behaviour of two strains of Leishmania after cultivation in a defined medium. Mem Inst Oswaldo Cruz 1987; 82:557-61. [PMID: 3507919 DOI: 10.1590/s0074-02761987000400014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Attempts have been made to characterize two strains of Leishmania that became infective to golden hamsters only after they had been maintained for several years in a chemically defined culture medium. Observations were made on the growth rates of promastigotes in vitro, course of infection in hamsters, morphology of amastigotes, and electrophoretic mobility patterns of eight isoenzymes. Information was obtained about the buoyant densities of n-DNA and k-DNA, and one strain was tested against monoclonal antibodies. The identity of both strains remains obscure.
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Affiliation(s)
- M N Melo
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, MG, Brasil
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48
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Antunes CM, Mayrink W, Magalhaes PA, Costa CA, Melo MN, Dias M, Michalick MS, Williams P, Lima AO, Vieira JB. Controlled field trials of a vaccine against New World cutaneous leishmaniasis. Int J Epidemiol 1986; 15:572-80. [PMID: 3546170 DOI: 10.1093/ije/15.4.572] [Citation(s) in RCA: 109] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Two controlled, double blind field trials of a non-living promastigote vaccine against New World Cutaneous Leishmaniasis (NWCL) were conducted in 1981 and 1983 in Brazil. Brazilian Army conscripts were randomly assigned to the vaccine or placebo groups and tested during their training in the Amazon jungle, a high risk area for NWCL. The results obtained showed: no significant differences between the vaccine and the placebo groups with respect to a number of characteristics (age, race, previous contact with the jungle, etc.); no significant differences between the participants who got and who did not get NWCL during the trial, with respect to length of exposure, contact with the jungle, etc. and a reduction of 67.3 and 85.7% in the annual incidence rate of NWCL, in 1981 and 1983 respectively (although the difference between incidence rates of the disease in vaccinated and control groups in the 1983 trial was not statistically significant), among those vaccinated who had converted to a positive leishmanin skin test as compared with the placebo groups.
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49
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Mayrink W, Antunes CM, Da Costa CA, Melo MN, Dias M, Michalick MS, Magalhães PA, De Oliveira Lima A, Williams P. Further trials of a vaccine against American cutaneous leishmaniasis. Trans R Soc Trop Med Hyg 1986; 80:1001. [PMID: 3299899 DOI: 10.1016/0035-9203(86)90296-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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50
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Mayrink W, Williams P, da Costa CA, Magalhães PA, Melo MN, Dias M, Oliveira Lima A, Michalick MS, Ferreira Carvalho E, Barros GC. An experimental vaccine against American dermal leishmaniasis: experience in the State of Espírito Santo, Brazil. Ann Trop Med Parasitol 1985; 79:259-69. [PMID: 4026438 DOI: 10.1080/00034983.1985.11811917] [Citation(s) in RCA: 76] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A vaccine prepared from killed and sonicated promastigotes of five Brazilian strains of Leishmania was used during an epidemic of American dermal leishmaniasis that occurred in Viana county, State of Espírito Santo, Brazil. Initially, all of the participants in the vaccination programme had negative reactions to Montenegro antigen. Forty days after the last dose of vaccine had been given, 87.6% of the 216 vaccinated individuals had become Montenegro-positive whereas the 266 unvaccinated persons remained Montenegro-negative. The study area had an unstable population and details are given about the human population changes that occurred during the two-year study period. Taking into account population movements, 1.5% of those vaccinated and 6.4% of the unvaccinated group developed dermal leishmanial lesions by the end of the first year. At the end of the second year, 1.7% of those vaccinated and 8.9% of the unvaccinated group had become infected. The difference in infection rates of the two groups is statistically significant at both the end of the first and second years of observation. Diagnosis of the disease(s) was based on the clinical appearance of lesions combined with parasitological and/or immunological evidence and subsequent responses to treatment. The experience gained in Viana also provided information about the storage and administration of the experimental vaccine which have been used in mounting a randomized clinical trial.
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