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1.
Transgenic Res ; 33(4): 159-174, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38856866

RESUMO

Plants evolved, over millions of years, complex defense systems against pathogens. Once infected, the interaction between pathogen effector molecules and host receptors triggers plant immune responses, which include apoptosis, systemic immune response, among others. An important protein family responsible for pathogen effector recognition is the nucleotide binding site-leucine repeat rich (NBS-LRR) proteins. The NBS-LRR gene family is the largest disease resistance gene class in plants. These proteins are widely distributed in vascular plants and have a complex multigenic cluster distribution in plant genomes. To counteract the genetic load of such a large gene family on fitness cost, plants evolved a mechanism using post transcriptional gene silencing induced by small RNAs, particularly microRNAs. For the NBS-LRR gene family, the small RNAs involved in this silencing mechanism are mainly the microRNA482/2118 superfamily. This suppression mechanism is relieved upon pathogen infection, thus allowing increased NBS-LRR expression and triggering plant immunity. In this review, we will discuss the biogenesis of microRNAs and secondary RNAs involved in this silencing mechanism, biochemical and structural features of NBS-LRR proteins in response to pathogen effectors and the evolution of microRNA-based silencing mechanism with a focus on the miR482/2118 family. Furthermore, the biotechnological manipulation of microRNA expression, using both transgenic or genome editing approaches to improve cultivated plants will be discussed, with a focus on the miR482/2118 family in soybean.


Assuntos
Regulação da Expressão Gênica de Plantas , MicroRNAs , Imunidade Vegetal , Proteínas de Plantas , MicroRNAs/genética , Imunidade Vegetal/genética , Proteínas de Plantas/genética , Resistência à Doença/genética , Resistência à Doença/imunologia , Produtos Agrícolas/genética , Produtos Agrícolas/imunologia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia
2.
Appl Opt ; 63(1): 17-29, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38175001

RESUMO

A test station setup devised to measure the emission characteristics and beam propagation parameters of a light detection and ranging (LiDAR) system is presented. The main blocks of the station to measure the accessible emission, wavelength peak and FWHM, pulse duration, pulse repetition rate, horizontal and vertical angular resolution, field of view, beam propagation factor M 2, beam waist size, waist location, and divergence are described. The performance of this test station was demonstrated using a commercial spinning LiDAR, a Velodyne VLP-16, which successfully enables these measurements for a laser beam with a wavelength of 913 nm.

3.
Primates ; 64(6): 581-587, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37656337

RESUMO

The lesser spot-nosed monkey (Cercopithecus petaurista) is a widely distributed West African guenon, which is generally considered less vulnerable to local extinctions than many sympatric primate species. Guinea-Bissau harbours the westernmost populations of the species, which is thought to be very rare or even extinct on the mainland, but to have putative populations on some islands of the Bijagós Archipelago. However, due to a lack of regional studies, baseline information on these insular populations is missing. We collected baseline data on the anthropogenic activities that possibly threaten the long-term conservation of this primate by using non-systematic ethnographic methodologies. The species was reported to be decreasing in number or rare by locals on two of the islands, and we identified two main conservation threats to it: generalised habitat loss/degradation, and hunting. While subsistence hunting has been recorded before in these areas, we report, to the best of our knowledge for the first time for these islands, the presence of a semi-organised commercial wild meat trade. The carcasses of western lesser spot-nosed monkeys were observed being stored and shipped from seaports to be sold at urban hubs (Bissau and Bubaque Island). The effect of commercial trade on the species could be severe, considering the small, naturally occurring, carrying capacities typical of insular ecosystems. The results of this study highlight the importance of understanding the leading social drivers of wild meat hunting of lesser spot-nosed monkeys on the Bijagós Archipelago, and the need to conduct baseline research on these insular populations, for which qualitative and quantitative methods could be combined.


Assuntos
Cercopithecus , Ecossistema , Animais , Guiné-Bissau , Haplorrinos , África Ocidental
5.
Curr Opin Plant Biol ; 71: 102331, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36603392

RESUMO

Soybean is one of the most important protein sources for human consumption and livestock feed. Soy production also allows the biosynthesis of edible oils, biodiesel, and biofertilizers. With the advent of modern agricultural biotechnology, soybean plants have also converted into bioreactors of therapeutic proteins and industrial enzymes. Soybean's characteristics, such as protein storage vacuoles (PSVs) and other unique organelles, allow the plant to be exploited as an accumulator of heterologous proteins under high stability and scalability conditions, and that maintains its basic functions. This review reports the main aspects of heterologous protein accumulation in soybean PSVs.


Assuntos
Glycine max , Proteínas de Soja , Humanos , Glycine max/genética , Glycine max/metabolismo , Proteínas de Soja/genética , Proteínas de Soja/metabolismo , Vacúolos/metabolismo , Sementes/metabolismo , Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
6.
Br Poult Sci ; 64(1): 137-141, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36129037

RESUMO

1. This study evaluated the minimal inhibitory concentration (MIC) of ciprofloxacin and the presence of plasmid-mediated quinolone resistance (PMQR) mechanisms in 97 nontyphoidal Salmonella spp. isolated from broilers and carcases from three different regions in Brazil. The presence of mutations in quinolone resistance determination regions (QRDRS) was investigated in the ciprofloxacin-resistant strain by DNA sequencing.2. Most of the Salmonella spp. (85.6%) had intermediate resistance to ciprofloxacin and only one isolate was resistant. MIC breakpoints ranged from ≤0.03 to 1 µg/ml and 67.0% of the strains had a MIC of 0.25 µg/ml (n=65). Thirteen strains (13.4%) were susceptible to ciprofloxacin with MIC ≤0.06 µg/ml. The qnrB gene was detected in eight isolates with intermediate resistance and in two susceptible strains. The other PMQR genes, qnrA, qnrC, qnrD, qnrS, qnrVC, aac(6')-Ib, qepA, oqxAB and mutations in QRDR were not detected in any strain.3. There was a high frequency of ciprofloxacin intermediate resistant Salmonella from broiler and broiler carcases from Brazil. The presence of these strains in poultry and derived products poses a risk to public health.


Assuntos
Ciprofloxacina , Quinolonas , Animais , Ciprofloxacina/farmacologia , Galinhas , Brasil , Proteínas de Bactérias/genética , Salmonella , Quinolonas/farmacologia , Testes de Sensibilidade Microbiana/veterinária , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética
8.
Arq. bras. med. vet. zootec. (Online) ; 73(2): 293-301, Mar.-Apr. 2021. tab, graf, mapas
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1248917

RESUMO

Mycoplasma bovis is a highly contagious agent associated with several pathologies in cattle. The detection of reactive antibodies to M. bovis by Indirect Enzyme-Linked Immunosorbent Assay (iELISA) identifies if there was an exposure to the microorganism. The current study aimed to optimize an iELISA from M. bovis total cell antigen, applying it to bovine serum samples, and to evaluate risk factors. Serum samples were obtained from 400 cows from 17 herds from Southeast Brazil. In the optimization of iELISA, the following was established: 2 µg/mL of antigen, sera dilution 1:300, and conjugate dilution 1:15000. The frequency was 62.3% (249/400) of reactive animals and 100% (17/17) of reactive herds. Risk factors were: herds with more than 100 animals (OR= 3.1; CI= 95%); Holstein breed (OR= 72.5; CI= 95%); cows (OR= 29.7; CI= 95%); intensive breeding system (OR= 3.3; CI= 95%); associated small ruminant production (OR= 4.4; CI= 95%); milk production above 500L (OR= 2.9; CI= 95%); no quarantine (OR= 1.5; CI= 95%); mechanical milking (OR= 5.5; CI= 95%) and cases of mastitis (OR= 5.5; CI= 95%). The proposed iELISA was able to detect antibodies reactive to M. bovis in bovine serum. Knowledge of these risk factors can assist in the implementation of prophylactic measures.(AU)


Mycoplasma bovis é um agente altamente contagioso relacionado a várias patologias em bovinos. A detecção de anticorpos reativos a M. bovis por Ensaio de Imunoadsorção Enzimática Indireto (iELISA) identifica se houve exposição ao microrganismo. O presente estudo teve como objetivo otimizar um iELISA de antígeno celular total de M. bovis, aplicando-o a amostras de soro bovino, bem como avaliar fatores de risco. Amostras de soro foram obtidas de 400 vacas de 17 rebanhos da Região Sudeste do Brasil. Na otimização do iELISA foram obtidos: 2µg/mL de antígeno, diluição dos soros 1:300 e do conjugado 1:15000. A frequência de animais reativos foi de 62,3% (249/400) e de 100% (17/17) para os rebanhos. Os fatores de risco foram: rebanhos com mais de 100 animais (OR= 3,1; IC= 95%); raça Holandesa (OR= 72,5;IC= 95%); vacas (OR= 29,7;IC= 95%); sistema intensivo (OR= 3,3; C= 95%); produção de pequenos ruminantes (OR= 4,4;IC=95%); produção de leite acima de 500L (OR= 2,9;IC= 95%); sem quarentena (OR= 1,5;IC= 95%); ordenha mecânica (OR= 5,5;IC= 95%) e casos de mastite (OR= 5,5;IC= 95%). O iELISA proposto foi capaz de detectar anticorpos reativos a M. bovis no soro bovino. O conhecimento desses fatores de risco pode auxiliar na implementação de medidas profiláticas.(AU)


Assuntos
Animais , Feminino , Bovinos , Mycoplasma bovis/isolamento & purificação , Mastite Bovina/complicações , Infecções por Mycoplasma/diagnóstico , Infecções por Mycoplasma/veterinária , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Fatores de Risco
9.
Arq. bras. med. vet. zootec. (Online) ; 72(4): 1346-1352, July-Aug. 2020. tab, ilus
Artigo em Português | LILACS, VETINDEX | ID: biblio-1131507

RESUMO

O objetivo deste trabalho foi estudar a prevalência de MG e MS e a filogenia das cepas circulantes, comparando-as com outras já descritas em poedeiras comerciais no Brasil. Foram coletados 140 suabes traqueais de poedeiras comerciais com sinais respiratórios em seis granjas da região centro-oeste de São Paulo. As amostras foram avaliadas por PCR, com posterior sequenciamento e análise filogenética das cepas identificadas. Das 140 amostras, 16,4% foram positivas para MG e 68,6% para MS. Houve diferença significativa nas frequências de MG e MS por granja, segundo o teste G de independência (P<0,05). Todas as cepas identificadas de MG e MS de granjas distintas apresentaram similaridade tanto pela lipoproteína para MG quanto pela região 16s rRNA para MS. Neste estudo, foi possível observar altas prevalências dos agentes estudados, sendo a de MS maior que a de MG. Foi detectada infecção mista por MG e MS em 11,4% das amostras e sabe-se que esses micoplasmas podem agir de forma sinérgica, agravando o quadro respiratório. As cepas circulantes identificadas, pela análise das regiões gênicas da lipoproteína para MG e 16S rRNA para MS, são similares em todas as granjas estudadas.(AU)


The aim of this study was to evaluate the prevalence of MG and MS and the phylogeny of the circulating strains, comparing them with others already described in commercial laying hens from Brazil. A total of 140 tracheal swabs were collected from commercial laying hens with respiratory signs in six farms from the western region of São Paulo state. The samples were analyzed by PCR with subsequent sequencing and phylogenetic analysis of the identified strains. From the 140 samples, 68.6% were positive for MS and 16.4% for MG. There was a significant difference in the frequencies of MG and MS per farm according to G Test of independence (P<0.05). All strains identified as MG and MS from distinct farms presented similarity both by lipoprotein to MG and by 16s rRNA region to MS. In this study, it was possible to observe a high prevalence of MS compared to MG. Mixed MG and MS infection was detected in 11.4% of the samples. These mycoplasmas may act synergistically, worsening the respiratory signs. The circulating strains identified by analysis of the lipoprotein for MG and 16S rRNA for MS are similar on all poultry farms studied.(AU)


Assuntos
Animais , Filogenia , Aves Domésticas , Galinhas/microbiologia , Mycoplasma gallisepticum , Mycoplasma synoviae , Estudos Transversais
13.
J Helminthol ; 92(2): 210-215, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28397630

RESUMO

The aims of the present study were to identify and describe the occurrence of nematode parasites in the gonads of bluefish Pomatomus saltatrix from off the coast of the state of Rio de Janeiro, Brazil. Only females were found to be parasitized by the nematodes, which were identified as P. saltatrix using morphological, morphometric and molecular data. Infection of female bluefish by this nematode had the following values: prevalence, 48.7%; mean intensity, 2.6; mean abundance, 1.3; and range of infection, 1-10 specimens. Histopathological examination of transverse and longitudinal sections of the parasitized ovaries showed nematodes at different stages of development among oocytes, but no indication of any associated inflammatory reaction. The presence of nematodes in the ovaries of bluefish is an important indication of fish hygiene, and parasitized fish are usually rejected by consumers because of their repugnant appearance.


Assuntos
Doenças dos Peixes/parasitologia , Nematoides/isolamento & purificação , Infecções por Nematoides/parasitologia , Ovário/parasitologia , Perciformes/parasitologia , Animais , Brasil/epidemiologia , Feminino , Doenças dos Peixes/epidemiologia , Estágios do Ciclo de Vida , Nematoides/classificação , Infecções por Nematoides/epidemiologia
14.
J Clin Pharm Ther ; 43(1): 150-153, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29063621

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Impetigo is a highly contagious bacterial skin infection and is one of the most common skin infections in children. Antibiotics are the first-line treatment when multiple lesions exist, but with an increasing prevalence of antibiotic-resistant bacteria the successful management of impetigo in the future is an area of concern. COMMENT: Current treatment options that favour the use of oral antibiotic therapy are increasingly problematic. Widespread use of these agents contributes to antimicrobial resistance and has adverse consequences for individuals and communities. There is a need for new topical antimicrobials and antiseptics as an alternative treatment strategy. WHAT IS NEW AND CONCLUSION: To successfully treat impetigo into the future and ensure that therapy does not contribute to bacterial resistance, additional research is required to ascertain the usefulness of alternative agents, including new topical antimicrobials and antiseptics.


Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Farmacorresistência Bacteriana/efeitos dos fármacos , Impetigo/tratamento farmacológico , Bactérias/efeitos dos fármacos , Humanos
15.
Arq. bras. med. vet. zootec. (Online) ; 70(3): 667-674, maio-jun. 2018. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-911019

RESUMO

The present paper is the first to perform this evaluation in dogs from the cities of Natividade, Porciuncula and Varre-Sai. The aim of this study is to search for Spotted Fever Group Rickettsia in canine sera using indirect immunofluorescence assay and to identify the probable causative agent of sera reactions in animals. Of the 253 sampled canines, 67.59% (171/253) were seroreactive for Rickettsia rickettsii and 11.07% (28/253) for Rickettsia parkeri, both in dilution 1:64. Titration of tested sera against R. rickettsii antigens reached 1:131.072 and, for R. parkeri, 1:4.096. We conclude that dogs are important sentinels for R. rickettsii infection, and can be infected regardless of sex, age, the habit of visiting woodlands or being in direct contact with equines and capybaras. Serological diagnosis has highlighted many dogs infected by R. rickettsii, and ambient conditions, such as the presence of flowing water bodies, was important for the occurrence of Brazilian Spotted Fever in the northwestern of Rio de Janeiro State.(AU)


O presente trabalho é o primeiro a ser realizado com cães nos municípios de Natividade, Porciúncula e Varre-Sai e tem por objetivo pesquisar Rickettsias do Grupo da Febre Maculosa em soros de cães, por meio da reação de imunofluorescência indireta, e identificar o provável agente causador da reação sorológica nos animais. Dos caninos amostrados, 67,59% (171/253) foram sororreativos para Rickettsia rickettsii e 11,07% (28/253) para Rickettsia parkeri, ambos em diluição de 1:64. A titulação dos soros testados contra antígenos de R. rickettsii chegou a 1:131.072, e para R. parkeri, 1:4.096. Conclui-se que cães são importantes sentinelas para a infecção por R. rickettsii, independente de sexo, idade, hábito de visitar ambientes florestais ou de estarem em contato direto com equinos e capivaras. O diagnóstico sorológico permitiu evidenciar muitos cães infectados por R. rickettsii, e condições ambientais, como a presença de áreas ribeirinhas, foram importantes para a ocorrência de Febre Maculosa Brasileira na região noroeste do Estado do Rio de Janeiro.(AU)


Assuntos
Animais , Cães , Cães/microbiologia , Rickettsia rickettsii , Estudos Soroepidemiológicos , Febre Maculosa das Montanhas Rochosas/epidemiologia
16.
J Environ Manage ; 193: 172-187, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28222351

RESUMO

In the last decades, the increasing vulnerability of floodplains is linked to societal changes such as population density growth, land use changes, water use patterns, among other factors. Land morphology directly influences surface water flow, transport of sediments, soil genesis, local climate and vegetation distribution. Therefore, the land morphology, the land used and management directly influences flood risks genesis. However, attention is not always given to the underlying geomorphological and ecological processes that influence the dynamic of rivers and their floodplains. Floodplains are considered a part of a larger system called Wet System (WS). The WS includes permanent and temporary streams, water bodies, wetlands and valley bottoms. Valley bottom is a broad concept which comprehends not only floodplains but also flat and concave areas, contiguous to streams, in which slope is less than 5%. This will be addressed through a consistent method based on a land morphology approach that classifies landforms according to their hydrological position in the watershed. This method is based on flat areas (slopes less than 5%), surface curvature and hydrological features. The comparison between WS and flood risk data from the Portuguese Environmental Agency for the main rivers of mainland Portugal showed that in downstream areas of watersheds, valley bottoms are coincident with floodplains modelled by hydrological methods. Mapping WS has a particular interest in analysing river ecosystems position and function in the landscape, from upstream to downstream areas in the watershed. This morphological approach is less demanding data and time-consuming than hydrological methods and can be used as the preliminary delimitation of floodplains and potential flood risk areas in situations where there is no hydrological data available. The results were also compared with the land use/cover map at a national level and detailed in Trancão river basin, located in Lisbon metropolitan area, an urbanized basin that suffered heavy flooding in the last decades. This study also contributes to a better understanding of the basin morphology at a local-scale and the effects of soil sealing in downstream flood risks. This work will contribute to the understanding of the morphology, ecology and land use of watersheds that could be used to reduce runoff and downstream flood risk. This can be accomplished by using natural water retention and infiltration methods or higher-level based planning instead of a reaction to local decisions on flood hazards. This morphological approach to map landforms, including wet system, is a valuable tool to assist policy makers and planners in flood risk and land use management, floodplain restoration, agricultural land management practices, and location of human activities according to ecological suitability.


Assuntos
Inundações , Rios , Ecossistema , Humanos , Portugal , Áreas Alagadas
17.
Eur J Clin Nutr ; 70(7): 859-62, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27004491

RESUMO

Undernutrition as well as low levels of vitamin B12 and folic acid are common problems among older adults. However, recommended routine nutritional status assessment tools may result in inadequate vitamin serum levels to go unnoticed. Therefore, the aim of this study is to evaluate the inadequacy of serum levels of vitamin B12 and folic acid within Mini Nutritional Assessment (MNA) classification categories among older adults. A cross-sectional study was conducted with 97 older adults residing in care homes in Portugal. Undernutrition was identified through the MNA, and serum levels of vitamin B12 and folic acid were measured using chemiluminescence. Cognitive function, depressive symptoms and functional characteristics were also assessed using the Abbreviated Mental Test Score, the Epidemiologic Studies Depression Scale and the Barthel Index, respectively. The mean age of older adults was 82.2 (6.3) years; 3.1% were undernourished and 26.8% were at undernutrition risk. In the MNA normal nutritional status group, 11.8% presented vitamin B12 deficiency (<200 pg/ml), 32.4% had low serum levels (200-400 pg/ml) and 4.4% had folic acid deficiency (<3 ng/ml). A high proportion of older adults with low serum levels of vitamin B12 presenting normal nutritional status by MNA was identified. This finding emphasizes the need to evaluate serum vitamin B12 levels, independently of the MNA results.


Assuntos
Avaliação Geriátrica , Avaliação Nutricional , Estado Nutricional , Deficiência de Vitamina B 12/epidemiologia , Vitamina B 12/sangue , Idoso , Idoso de 80 Anos ou mais , Cognição , Transtornos Cognitivos , Estudos Transversais , Depressão , Feminino , Ácido Fólico/sangue , Deficiência de Ácido Fólico/sangue , Deficiência de Ácido Fólico/epidemiologia , Hematínicos , Humanos , Luminescência , Masculino , Desnutrição/epidemiologia , Portugal , Valores de Referência , Deficiência de Vitamina B 12/sangue
18.
Braz J Biol ; 74(4): 854-60, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25627595

RESUMO

New northwestern records of the striped treefrog Hypsiboas caingua (Carrizo, 1991 "1990") are presented for Brazil, extending its known geographic distribution approximately 115 km northward (linear distance) of the previous northernmost record of the species. In all new localities, individuals of H. caingua were only found in calling activity under temperatures below 18°C. The species appears to be associated with Atlantic Forest, although it had already been recorded in Cerrado. Although the scientific literature data suggests that H. caingua presents discontinuous geographical distribution, three methods of distribution modelling based on climatic data show that the species' distribution is continuous. The gap in the distribution may be related to the lack of field surveys in the regions that connect these populations, especially in colder periods. Nevertheless, factors other than climate might also be responsible for the current distribution of H. caingua, since the species was absent in well-surveyed sites situated between the areas of modeled distribution. Therefore, further studies on natural history, populations' genetic structure, and geographic distribution models implementing factors other than climate will be important to elucidate some ecological and evolutionary aspects of the distribution of H. caingua in South America.


Assuntos
Anuros/classificação , Distribuição Animal , Animais , Brasil , Clima , Modelos Biológicos , Densidade Demográfica , Dinâmica Populacional
19.
Braz J Biol ; 72(3): 519-31, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22990823

RESUMO

Studies on Neotropical aquatic macrophytes have increased in recent decades, however species richness in wetlands of South America is far from being fully known. In addition, studies having an ecological approach are scarce in the Pantanal. Rapid assessments are essential for gaining knowledge of the biodiversity in the region. This study was performed in five sites of the Baía do Castelo, the western border of the Brazilian Pantanal, which included wild-rice patches, floating mats and floating meadows. At each site, plots of 0.5 × 0.5 m were set (n = 137), species of aquatic macrophytes were identified, their coverage was measured and the plot depth was estimated. We recorded 57 species in 26 families, of which Poaceae was the richest. The most frequent and abundant species was Commelina schomburgkiana; the second most frequent was Oryza latifolia,followed by Leersia hexandra, Enydra radicans and Pityrogramma calomelanos. The latter species was second in cover, followed by Pontederia rotundifolia, Eichhornia azurea, E. crassipes and Enydra radicans. These five species and C. schomburgkiana (the most abundant) together represent more than half of the coverage on the lake. Pontederia rotundifolia, Ludwigia helminthorrhiza, Pistia stratiotes, E. azurea, E. crassipes, Enydra radicans and Panicum elephantipes were strongly associated with deeper areas, while Oryza latifolia, Leersia hexandra and Salvinia auriculata were prevalent in shallow areas. Pityrogramma calomelanos, Ludwigia nervosa, Ipomoea alba, Cayaponia podantha, Polygonum acuminatum, Rhynchanthera novemnervia and Ludwigia leptocarpa were highly correlated with floating meadows. The structure of the habitat, natural dynamics and zonation of aquatic vegetation in the Baía do Castelo seems to be influenced by a variation in water levels, which promotes spatial segregation, most likely due to competition and/habitat preference.


Assuntos
Biodiversidade , Lagos , Magnoliopsida/classificação , Brasil , Densidade Demográfica , Estações do Ano
20.
Braz J Biol ; 72(3): 577-82, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22990829

RESUMO

Borrelia burgdorferi, the agent of Lyme borreliosis, is a spirochetes transmitted by ticks to humans and animals. Its cultivation in vitro in tick cells allows studies of its biology and provides methodology for future research in Brazil, and for the isolation of Borrelia spp. We examined in vitro the characteristics of embryonic cells of Rhipicephalus microplus and Amblyomma cajennense in cell culture and investigated the suitability of embryonic cells as a substrate for cultivation of B. burgdorferi. Subcultures were prepared from primary cultures of embrionary cells of R. microplus and A. cajennense maintained in Leibovitz's (L-15) complete medium at 28 ºC and 31 ºC, respectively. When a monolayer had formed, the L-15 was replaced with Barbour-Stoener-Kelly medium for experiments to infect cell cultures with B. burgdorferi. After 72 hours of cultivation, the spirochetes were counted using an inverted phase contrast microscope and dark-field illumination (400×). Survival, multiplication and the adherence of B. burgdorferi for embryonic cells of R. microplus and A. cajennense were observed. B. burgdorferi cultured with embryonic cells of R. microplus grew on average to a density (final count) of 2.4 × 10(7) spirochetes/mL, whereas in cell-free culture, an average of 2.5 × 10(7) spirochetes/mL were counted. When cultivated with A. cajennense cells, the final count of spirochetes was on average 1.7 × 10(7) spirochetes/mL, while spirochetes cultured under cell-free conditions replicated on average of 2.2 × 10(7) spirochetes/mL. Similar results were observed in the final count of Spirochetes cultivated in cells of R. microplus and A. cajennense, when compared with cell-free control. These results demonstrated that cells of R. microplus and A. cajennense have the potential to be used as growth substrate for B. burgdorferi in the study of its interaction with host cells.


Assuntos
Borrelia burgdorferi/crescimento & desenvolvimento , Ixodidae/citologia , Animais , Bovinos , Células Cultivadas , Feminino , Ixodidae/embriologia , Coelhos , Rhipicephalus/citologia , Rhipicephalus/embriologia
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