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Costa LF, Mol JPS, Silva APC, Macêdo AA, Silva TMA, Alves GES, Winter S, Winter MG, Velazquez EM, Byndloss MX, Bäumler AJ, Tsolis RM, Paixão TA, Santos RL. Iron acquisition pathways and colonization of the inflamed intestine by Salmonella enterica serovar Typhimurium. Int J Med Microbiol 2016; 306:604-610. [PMID: 27760693 DOI: 10.1016/j.ijmm.2016.10.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [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: 02/17/2016] [Revised: 10/11/2016] [Accepted: 10/12/2016] [Indexed: 12/11/2022] Open
Abstract
Salmonella enterica serotype Typhimurium is able to expand in the lumen of the inflamed intestine through mechanisms that have not been fully resolved. Here we utilized streptomycin-pretreated mice and dextran sodium sulfate (DSS)-treated mice to investigate how pathways for S. Typhimurium iron acquisition contribute to pathogen expansion in the inflamed intestine. Competitive infection with an iron uptake-proficient S. Typhimurium strain and mutant strains lacking tonB feoB, feoB, tonB or iroN in streptomycin pretreated mice demonstrated that ferric iron uptake requiring IroN and TonB conferred a fitness advantage during growth in the inflamed intestine. However, the fitness advantage conferred by ferrous iron uptake mechanisms was independent of inflammation and was only apparent in models where the normal microbiota composition had been disrupted by antibiotic treatment.
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Affiliation(s)
- Luciana F Costa
- Departamento de Patologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Juliana P S Mol
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ana Patricia C Silva
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal Minas Gerais, Belo Horizonte, MG, Brazil
| | - Auricélio A Macêdo
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal Minas Gerais, Belo Horizonte, MG, Brazil
| | - Teane M A Silva
- Departamento de Patologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Geraldo E S Alves
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal Minas Gerais, Belo Horizonte, MG, Brazil
| | - Sebastian Winter
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Maria G Winter
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Eric M Velazquez
- Department of Medical Microbiology and Immunology, University of California at Davis, Davis, CA, USA
| | - Mariana X Byndloss
- Department of Medical Microbiology and Immunology, University of California at Davis, Davis, CA, USA
| | - Andreas J Bäumler
- Department of Medical Microbiology and Immunology, University of California at Davis, Davis, CA, USA
| | - Renée M Tsolis
- Department of Medical Microbiology and Immunology, University of California at Davis, Davis, CA, USA.
| | - Tatiane A Paixão
- Departamento de Patologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Renato L Santos
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal Minas Gerais, Belo Horizonte, MG, Brazil.
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Silva TMA, Mol JPS, Winter MG, Atluri V, Xavier MN, Pires SF, Paixão TA, Andrade HM, Santos RL, Tsolis RM. The predicted ABC transporter AbcEDCBA is required for type IV secretion system expression and lysosomal evasion by Brucella ovis. PLoS One 2014; 9:e114532. [PMID: 25474545 PMCID: PMC4256435 DOI: 10.1371/journal.pone.0114532] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 11/10/2014] [Indexed: 12/23/2022] Open
Abstract
Brucella ovis is a major cause of reproductive failure in rams and it is one of the few well-described Brucella species that is not zoonotic. Previous work showed that a B. ovis mutant lacking a species-specific ABC transporter (ΔabcBA) was attenuated in mice and was unable to survive in macrophages. The aim of this study was to evaluate the role of this ABC transporter during intracellular survival of B. ovis. In HeLa cells, B. ovis WT was able to survive and replicate at later time point (48 hpi), whereas an ΔabcBA mutant was attenuated at 24 hpi. The reduced survival of the ΔabcBA mutant was associated with a decreased ability to exclude the lysosomal marker LAMP1 from its vacuolar membrane, suggesting a failure to establish a replicative niche. The ΔabcBA mutant showed a reduced abundance of the Type IV secretion system (T4SS) proteins VirB8 and VirB11 in both rich and acid media, when compared to WT B. ovis. However, mRNA levels of virB1, virB8, hutC, and vjbR were similar in both strains. These results support the notion that the ABC transporter encoded by abcEDCBA or its transported substrate acts at a post-transcriptional level to promote the optimal expression of the B. ovis T4SS within infected host cells.
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Affiliation(s)
- Teane M. A. Silva
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Juliana P. S. Mol
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Maria G. Winter
- Department of Medical Microbiology and Immunology, University of California Davis, Davis, California, United States of America
| | - Vidya Atluri
- Department of Medical Microbiology and Immunology, University of California Davis, Davis, California, United States of America
| | - Mariana N. Xavier
- Department of Medical Microbiology and Immunology, University of California Davis, Davis, California, United States of America
| | - Simone F. Pires
- Departamento de Parasitologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Tatiane A. Paixão
- Departamento de Patologia Geral, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Hélida M. Andrade
- Departamento de Parasitologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Renato L. Santos
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- * E-mail: (RLS); (RMT)
| | - Renee M. Tsolis
- Department of Medical Microbiology and Immunology, University of California Davis, Davis, California, United States of America
- * E-mail: (RLS); (RMT)
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Xavier MN, Winter MG, Spees AM, den Hartigh AB, Nguyen K, Roux CM, Silva TMA, Atluri VL, Kerrinnes T, Keestra AM, Monack DM, Luciw PA, Eigenheer RA, Bäumler AJ, Santos RL, Tsolis RM. PPARγ-mediated increase in glucose availability sustains chronic Brucella abortus infection in alternatively activated macrophages. Cell Host Microbe 2013; 14:159-70. [PMID: 23954155 PMCID: PMC3777723 DOI: 10.1016/j.chom.2013.07.009] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [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: 03/01/2013] [Revised: 05/17/2013] [Accepted: 06/20/2013] [Indexed: 01/16/2023]
Abstract
Eradication of persistent intracellular bacterial pathogens with antibiotic therapy is often slow or incomplete. However, strategies to augment antibiotics are hampered by our poor understanding of the nutritional environment that sustains chronic infection. Here we show that the intracellular pathogen Brucella abortus survives and replicates preferentially in alternatively activated macrophages (AAMs), which are more abundant during chronic infection. A metabolic shift induced by peroxisome proliferator-activated receptor γ (PPARγ), which increases intracellular glucose availability, is identified as a causal mechanism promoting enhanced bacterial survival in AAMs. Glucose uptake was crucial for increased replication of B. abortus in AAMs, and for chronic infection, as inactivation of the bacterial glucose transporter gluP reduced both intracellular survival in AAMs and persistence in mice. Thus, a shift in intracellular nutrient availability induced by PPARγ promotes chronic persistence of B. abortus within AAMs, and targeting this pathway may aid in eradicating chronic infection.
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Affiliation(s)
- Mariana N. Xavier
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
- Departamento de Clinica e Cirurgia Veterinarias, Escola de Veterinaria, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
| | - Maria G. Winter
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Alanna M. Spees
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Andreas B. den Hartigh
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Kim Nguyen
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Christelle M. Roux
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Teane M. A. Silva
- Departamento de Clinica e Cirurgia Veterinarias, Escola de Veterinaria, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
| | - Vidya L. Atluri
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Tobias Kerrinnes
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - A. Marijke Keestra
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Denise M. Monack
- Department of Microbiology & Immunology, School of Medicine, Stanford University, Palo Alto, CA, 94305, USA
| | - Paul A. Luciw
- Center for Comparative Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Richard A. Eigenheer
- Proteomics Core Facility, University of California at Davis Genome Center, Davis, CA, 95616, USA
| | - Andreas J. Bäumler
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Renato L. Santos
- Departamento de Clinica e Cirurgia Veterinarias, Escola de Veterinaria, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
| | - Renée M. Tsolis
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
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Xavier MN, Winter MG, Spees AM, Nguyen K, Atluri VL, Silva TMA, Bäumler AJ, Müller W, Santos RL, Tsolis RM. CD4+ T cell-derived IL-10 promotes Brucella abortus persistence via modulation of macrophage function. PLoS Pathog 2013; 9:e1003454. [PMID: 23818855 PMCID: PMC3688575 DOI: 10.1371/journal.ppat.1003454] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Accepted: 05/08/2013] [Indexed: 12/21/2022] Open
Abstract
Evasion of host immune responses is a prerequisite for chronic bacterial diseases; however, the underlying mechanisms are not fully understood. Here, we show that the persistent intracellular pathogen Brucella abortus prevents immune activation of macrophages by inducing CD4(+)CD25(+) T cells to produce the anti-inflammatory cytokine interleukin-10 (IL-10) early during infection. IL-10 receptor (IL-10R) blockage in macrophages resulted in significantly higher NF-kB activation as well as decreased bacterial intracellular survival associated with an inability of B. abortus to escape the late endosome compartment in vitro. Moreover, either a lack of IL-10 production by T cells or a lack of macrophage responsiveness to this cytokine resulted in an increased ability of mice to control B. abortus infection, while inducing elevated production of pro-inflammatory cytokines, which led to severe pathology in liver and spleen of infected mice. Collectively, our results suggest that early IL-10 production by CD25(+)CD4(+) T cells modulates macrophage function and contributes to an initial balance between pro-inflammatory and anti-inflammatory cytokines that is beneficial to the pathogen, thereby promoting enhanced bacterial survival and persistent infection.
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Affiliation(s)
- Mariana N. Xavier
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
- Departamento de Clínica e Cirurgia Veterinárias, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Maria G. Winter
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
| | - Alanna M. Spees
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
| | - Kim Nguyen
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
| | - Vidya L. Atluri
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
| | - Teane M. A. Silva
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
- Departamento de Clínica e Cirurgia Veterinárias, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Andreas J. Bäumler
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
| | - Werner Müller
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Renato L. Santos
- Departamento de Clínica e Cirurgia Veterinárias, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Renée M. Tsolis
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
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Moustacas VS, Silva TMA, Costa LF, Xavier MN, Carvalho CA, Costa ÉA, Paixão TA, Santos RL. Species-specific multiplex PCR for the diagnosis of Brucella ovis, Actinobacillus seminis, and Histophilus somni infection in rams. BMC Vet Res 2013; 9:51. [PMID: 23514236 PMCID: PMC3614447 DOI: 10.1186/1746-6148-9-51] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [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: 01/26/2013] [Accepted: 03/18/2013] [Indexed: 11/24/2022] Open
Abstract
Background Infectious ovine epididymitis results in substantial economic losses worldwide due to reproductive failure and culling of breeders. The most common causative agents of these infections are Brucella ovis, Actinobacillus seminis, and Histophilus somni. The aim of this study was to develop a multiplex PCR assay for simultaneous detection of Brucella ovis, Actinobacillus seminis, and Histophilus somni with species-specific primers applied to biological samples for molecular diagnosis of these infections. Results The multiplex assay was capable of detecting B. ovis, A. seminis, and H. somni DNA simultaneously from genomic bacterial DNA samples and pool of semen samples from experimentally infected rams. The method was highly specific since it did not amplify DNA from other bacterial species that can potentially cause epididymitis in rams as well as species phylogenetically related to B. ovis. All negative control samples were negative in PCR multiplex assay. Urine can be used as an alternative to semen samples. Conclusions The species-specific multiplex PCR assay developed in this study can be successfully used for the detection of three of the most common bacterial causes of ovine epididymitis.
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Affiliation(s)
- Valéria S Moustacas
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31270-901, Belo Horizonte, MG Brazil
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Sá JC, Silva TMA, Costa EA, Silva APC, Tsolis RM, Paixão TA, Carvalho Neta AV, Santos RL. The virB-encoded type IV secretion system is critical for establishment of infection and persistence of Brucella ovis infection in mice. Vet Microbiol 2012; 159:130-40. [PMID: 22483850 DOI: 10.1016/j.vetmic.2012.03.029] [Citation(s) in RCA: 19] [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: 01/21/2012] [Revised: 03/08/2012] [Accepted: 03/10/2012] [Indexed: 12/13/2022]
Abstract
Brucella spp. are gram-negative intracellular bacterial pathogens that cause chronic infections. Brucella virulence factors include a type IV secretion system (T4SS) and its lipopolysaccharide (LPS), which are essential for persistence. However, the role of the virB-encoded T4SS has not been investigated in naturally rough Brucella species such as Brucella ovis. In this study, male 6-week old BALBc mice were infected with B. ovis, Brucella abortus, and their respective ΔvirB2 mutant strains. During early infection, B. ovis and B. abortus wild type strains were similarly recovered from spleen. Interestingly, in contrast to ΔvirB2 B. abortus that was recovered at similar levels when compared to the wild type strain, the ΔvirB2 B. ovis was markedly attenuated as early as 24h post infection (hpi). The ΔvirB2 B. ovis was unable to survive and multiply in murine peritoneal macrophages and extracellularly within the peritoneal cavity at 12 and 24 hpi with lower splenic colonization than the parental strain at 6, 12 and 24 hpi. In contrast, wild type B. abortus and ΔvirB2 B. abortus had a similar kinetics of infection in this model. As expected, the T4SS was essential for intracellular replication of smooth and rough strains in RAW macrophages at 48 hpi. These results suggest that T4SS is important for survival of B. ovis in murine model, and that a T4SS deficient B. ovis strain is cleared at earlier stages of infection when compared to a similar B. abortus mutant.
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Affiliation(s)
- Joicy C Sá
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
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Pangrazio KK, Costa EA, Amarilla SP, Cino AG, Silva TMA, Paixão TA, Costa LF, Dengues EG, Diaz AAR, Santos RL. Tissue distribution of Leishmania chagasi and lesions in transplacentally infected fetuses from symptomatic and asymptomatic naturally infected bitches. Vet Parasitol 2009; 165:327-31. [PMID: 19647368 DOI: 10.1016/j.vetpar.2009.07.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 07/03/2009] [Accepted: 07/08/2009] [Indexed: 11/26/2022]
Abstract
Visceral leishmaniasis (VL) is primarily transmitted by an invertebrate vector, but transmission in the absence of the vector has been reported. Vertical transmission of VL has been described in man and dogs. The aim of this study was to evaluate the distribution of Leishmania amastigotes in fetal organs and histopathologic changes associated with parasitism and to determinate the frequency of transplacental transmission and potential of vertical transmission by symptomatic and asymptomatic pregnant bitches. Symptomatic (n=4) and asymptomatic (n=4) pregnant bitches, serologically and parasitologically positive for Leishmania sp., carrying a total of 53 fetuses (26 from symptomatic and 27 from asymptomatic bitches) were selected at the Veterinary Hospital of the National University of Asuncion, Paraguay. Samples of placenta and fetal organs such as liver, spleen, lymph nodes, bone marrow, kidney and heart were histologically evaluated and processed for immunodetection of amastigotes and PCR. There were no lesions compatible with VL in fetal tissues in spite of the presence of amastigotes, particularly in lymphoreticular tissues. However, fetal hepatocytes had marked degenerative changes that were independent of the presence of amastigotes in liver. Twenty-six out of 53 placentas (13 symptomatic and 13 asymptomatic) and a total of 17 fetuses out of 53 (nine symptomatic and eight asymptomatic) were PCR positive. Together these findings indicate a high frequency of transplacental transmission and no differences in the potential of transmission when symptomatic were compared to asymptomatic pregnant bitches.
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Affiliation(s)
- Kristel Kegler Pangrazio
- Departamento de Ciencias Patológicas, Facultad de Ciencias Veterinarias, Universidad Nacional de Asunción, Ruta Mcal. Estigarribia km 10, San Lorenzo, Paraguay
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Luppi MM, Malta MCC, Silva TMA, Silva FL, Motta ROC, Miranda I, Ecco R, Santos RL. Visceral leishmaniasis in captive wild canids in Brazil. Vet Parasitol 2008; 155:146-51. [PMID: 18556130 DOI: 10.1016/j.vetpar.2008.04.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 03/14/2008] [Accepted: 04/21/2008] [Indexed: 11/28/2022]
Abstract
Visceral leishmaniasis (VL) is endemic in Belo Horizonte (State of Minas Gerais, Brazil). Leishmania sp. can naturally infect several species of mammals, and the domestic dog is the most important reservoir of the disease in South America. This report describes five cases of visceral leishmaniasis in Brazilian canids. Among 15 animals kept in captivity in a zoo in Belo Horizonte (State of Minas Gerais, Brazil), two animals, a bush dog (Spheotos venaticos) and a hoary zorro (Lycalopex vetulus) were serologically positive and developed clinical signs of VL, whereas three other canids, including a crab-eating fox (Cerdocyon thous), a maned wolf (Chrysocyon brachyurus), and a hoary zorro (Lycalopex vetulus) had positive serological results without clinical signs.
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Affiliation(s)
- Marcela M Luppi
- Fundação Zoo-Botânica de Belo Horizonte, Av. Otacílio Negrão de Lima 8000, 31365-450 Belo Horizonte, MG, Brazil
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Silva FL, Rodrigues AAM, Rego IOP, Santos RLH, Oliveira RG, Silva TMA, Xavier MN, Nascimento EF, Santos RL. Genital lesions and distribution of amastigotes in bitches naturally infected with Leishmania chagasi. Vet Parasitol 2007; 151:86-90. [PMID: 18006233 DOI: 10.1016/j.vetpar.2007.09.032] [Citation(s) in RCA: 27] [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: 06/05/2007] [Revised: 09/24/2007] [Accepted: 09/24/2007] [Indexed: 10/22/2022]
Abstract
Recent reports indicate that Leishmania chagasi has tropism to the male canine genital system, which is associated with shedding of the organism in the semen, supporting the hypothesis of venereal transmission. The aim of this study was to describe the lesions and assess parasite load in the genital system of bitches with canine visceral leishmaniasis (CanL). Symptomatic (n=5) and asymptomatic (n=5) bitches seropositive for CanL were randomly selected at the Center for Zoonosis Control (Belo Horizonte, State of Minas Gerais, Brazil). Five serologically negative, healthy, adult bitches also from the CZC were used as controls. Samples from genital organs (vulva, vagina, cervix, uterine body, uterine horns, uterine tubes, and ovaries), liver, and spleen were histologically evaluated and processed for immunodetection of Leishmania sp., and PCR. The most significant histological change was a mild to moderate vulvar dermatitis, characterized by a histio-plasma-lymphocytic infiltrate. This change was detected in all asymptomatic, four symptomatic, and three uninfected control bitches. In one symptomatic and one asymptomatic bitch intracytoplasmic amastigotes were observed within macrophages in the inflammatory infiltrate. Samples from all the segments of the genital tract were positive in at least one infected animal, in the absence of detectable amastigotes in the tissue. These findings support the notion that L. chagasi does not have genital tropism in the bitch, which is in contrast to our previous findings in naturally infected male intact dogs.
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Affiliation(s)
- Fabiana L Silva
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Av Antônio Carlos, 6627, 31270-901, Belo Horizonte, MG, Brazil
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Silva TMA, Alves LG, de Queiroz KCS, Santos MGL, Marques CT, Chavante SF, Rocha HAO, Leite EL. Partial characterization and anticoagulant activity of a heterofucan from the brown seaweed Padina gymnospora. Braz J Med Biol Res 2005; 38:523-33. [PMID: 15962177 DOI: 10.1590/s0100-879x2005000400005] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [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 brown algae Padina gymnospora contain different fucans. Powdered algae were submitted to proteolysis with the proteolytic enzyme maxataze. The first extract of the algae was constituted of polysaccharides contaminated with lipids, phenols, etc. Fractionation of the fucans with increasing concentrations of acetone produced fractions with different proportions of fucose, xylose, uronic acid, galactose, and sulfate. One of the fractions, precipitated with 50% acetone (v/v), contained an 18-kDa heterofucan (PF1), which was further purified by gel-permeation chromatography on Sephadex G-75 using 0.2 M acetic acid as eluent and characterized by agarose gel electrophoresis in 0.05 M 1,3 diaminopropane/acetate buffer at pH 9.0, methylation and nuclear magnetic resonance spectroscopy. Structural analysis indicates that this fucan has a central core consisting mainly of 3-beta-D-glucuronic acid 1-> or 4-beta-D-glucuronic acid 1 ->, substituted at C-2 with alpha-L-fucose or beta-D-xylose. Sulfate groups were only detected at C-3 of 4-alpha-L-fucose 1-> units. The anticoagulant activity of the PF1 (only 2.5-fold lesser than low molecular weight heparin) estimated by activated partial thromboplastin time was completely abolished upon desulfation by solvolysis in dimethyl sulfoxide, indicating that 3-O-sulfation at C-3 of 4-alpha-L-fucose 1-> units is responsible for the anticoagulant activity of the polymer.
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Affiliation(s)
- T M A Silva
- Laboratório de Glicobiologia, Departamento de Bioquímica, Universidade Federal do Rio Grande do Norte, Natal, Brasil
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