118 resultados para Borrelia-burgdorferi


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Lyme Disease is a tick-borne (specially by Ixodes ticks) immune-mediated inflammatory disorder caused by a newly recognize spirochete, Borrelia burgdorferi. Indirect fluorescent antibody (IF) staining methods and enzyme-linked immunosorbent assay are frequently relied upon to confirm Lyme borreliosis infections. Although serologic testing for antibodies has limitations, it is still the only practical means of confirming B. burgdorferi infections. Because we have no previous report of Lyme disease in human inhabitants in Argentina, a study was designed as a seroepidemiologic investigation of the immune response to B. burgdorferi in farm workers of Argentina with arthritis symptoms. Three out of 28 sera were positive (#1,5 and 9). Serum # 1 was positive for Immunoglobulin G at dilution 1:320, serum # 5 and # 9 both to dilution 1:160; while for Immunoglobulin M all (#1, 5 and 9) were positive at low dilution (1:40) using IF. The results showed that antibodies against B. burgdorferi are present in an Argentinian population. Thus caution should be exercised in the clinical interpretation of arthritis until the presence of B. burgdorferi be confirmed by culture in specific media.

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Dogs sera samples collected from Cotia County, São Paulo were tested using indirect immunoenzymatic test (ELISA) in order to study Lyme disease serology in dogs. ELISA method was standardized and G39/40 North American strain of Borrelia burgdorferi was used as antigen. Positive results were confirmed employing the Western blotting technique. Because of the possibility of cross-reactions, sera were also tested for different serological strains of Leptospira interrogans and L. biflexa using microscopic sera agglutination test. Twenty-three of 237 (9.7%) serum samples were positive in the ELISA; 20 of them (86.9%) were confirmed by the Western blotting, what suggests that Cotia may be a risk area for Lyme disease. Although 4 samples (1.7%) were positive for Lyme disease and leptospirosis, no correlation was found between the results (X² = 0.725; p = 0.394) what suggests absence of serological cross reactivity.

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Dissertação para obtenção do grau de Mestre em Microbiologia Médica

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In order to evaluate the presence of specific IgG antibodies to Borrelia burgdorferi in patients with clinical manifestations associated with Lyme borreliosis in Cali, Colombia, 20 serum samples from patients with dermatologic signs, one cerebrospinal fluid (CSF) sample from a patient with chronic neurologic and arthritic manifestations, and twelve serum samples from individuals without clinical signs associated with Lyme borreliosis were analyzed by IgG Western blot. The results were interpreted following the recommendations of the Centers for Diseases Control and Prevention (CDC) for IgG Western blots. Four samples fulfilled the CDC criteria: two serum specimens from patients with morphea (localized scleroderma), the CSF from the patient with neurologic and arthritic manifestations, and one of the controls. Interpretation of positive serology for Lyme disease in non-endemic countries must be cautious. However these results suggest that the putative "Lyme-like" disease may correlate with positivity on Western blots, thus raising the possibility that a spirochete genospecies distinct from B. burgdorferi sensu stricto, or a Borrelia species other than B. burgdorferi sensu lato is the causative agent. Future work will focus on a survey of the local tick and rodent population for evidence of spirochete species that could be incriminated as the etiologic agent.

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The aim of the present study was to assess the possible use of a modified medium, prepared in the laboratory using the constituents of Barbour-Stonner-Kelly (BSK) medium and medium 199 as base, for the culture of Borrelia strains, comparing the growth of individual strains in this medium and in the BSK-H medium, and the protein profile and antigenic characteristics of Borrelia proteins expressed in these media. A qualitative evaluation of growth of Borrelia species was made with acceptable results (morphology and motility), but during a quantitative evaluation using the three main genospecies of Borrelia, the better results were obtained with a B. burgdorferi sensu stricto strain. The modified medium did not enable the growth of a B. afzelii strain. The protein profile and antigenic characteristic of the expressed proteins in the modified medium were studied with satisfactory results. These results suggest the modified medium as an alternative for the cultivation of Borrelia strains, with some limitations, in poorly-resourced laboratories.

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BACKGROUND: The long latent stage seen in syphilis, followed by chronic central nervous system infection and inflammation, can be explained by the persistence of atypical cystic and granular forms of Treponema pallidum. We investigated whether a similar situation may occur in Lyme neuroborreliosis. METHOD: Atypical forms of Borrelia burgdorferi spirochetes were induced exposing cultures of Borrelia burgdorferi (strains B31 and ADB1) to such unfavorable conditions as osmotic and heat shock, and exposure to the binding agents Thioflavin S and Congo red. We also analyzed whether these forms may be induced in vitro, following infection of primary chicken and rat neurons, as well as rat and human astrocytes. We further analyzed whether atypical forms similar to those induced in vitro may also occur in vivo, in brains of three patients with Lyme neuroborreliosis. We used immunohistochemical methods to detect evidence of neuroinflammation in the form of reactive microglia and astrocytes. RESULTS: Under these conditions we observed atypical cystic, rolled and granular forms of these spirochetes. We characterized these abnormal forms by histochemical, immunohistochemical, dark field and atomic force microscopy (AFM) methods. The atypical and cystic forms found in the brains of three patients with neuropathologically confirmed Lyme neuroborreliosis were identical to those induced in vitro. We also observed nuclear fragmentation of the infected astrocytes using the TUNEL method. Abundant HLA-DR positive microglia and GFAP positive reactive astrocytes were present in the cerebral cortex. CONCLUSION: The results indicate that atypical extra- and intracellular pleomorphic and cystic forms of Borrelia burgdorferi and local neuroinflammation occur in the brain in chronic Lyme neuroborreliosis. The persistence of these more resistant spirochete forms, and their intracellular location in neurons and glial cells, may explain the long latent stage and persistence of Borrelia infection. The results also suggest that Borrelia burgdorferi may induce cellular dysfunction and apoptosis. The detection and recognition of atypical, cystic and granular forms in infected tissues is essential for the diagnosis and the treatment as they can occur in the absence of the typical spiral Borrelia form.

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Lyme borreliosis is a tick-transmitted infection caused by the spirochete bacterium Borrelia burgdorferi sensu lato. The tick injects bacteria into host skin, where a first line defence, mainly the complement system, neutrophils, dendritic cells and macrophages are ready to attack foreign intruders. However, in the case of Lyme borreliosis, the original immune response in the skin is untypically mild among bacterial infections. A further untypical feature is the ability of B. burgdorferi to disseminate to distant organs, where, in some patients, symptoms appear after years after the original infection. This study aimed at uncovering some of the immune evasion mechanisms utilized by B. burgdorferi against the complement system, neutrophils and dendritic cells. B. burgdorferi was shown to inhibit chemotaxis of human neutrophils towards nformyl- methyl-leucyl-phenylalanine (fMLP). Outer surface protein B (OspB) of B. burgdorferi was shown to promote resistance to the attack of the complement system and neutrophil phagocytosis at low complement concentrations. B. burgdorferi was shown to inhibit migration of dendritic cells in vitro towards CCL19 and CCL21 and also in an in vivo model. This effect was shown to be due to the absence of CD38 on the borrelia-stimulated dendritic cell surface. A defect in p38 mitogen-activated-protein-kinase (p38) signaling was linked to defective CD38 expression. A defect in CD38 expression on B. burgdorferi-stimulated neutrophils was also observed. In this study, a number of novel immune evasion strategies utilized by B burgdorferi were chracterized. However, further studies are needed as other immune evasion mechanisms await to be uncovered.

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Borrelia burgdorferi infektoitujen hiirten antibioottihoidon jälkeinen oireilu Lymen borrelioosi on puutiaisten välittämä monimuotoinen infektiotauti, jonka tunnetuin oire on ns. vaeltava ihottuma eli erythema migrans. Muita tavallisia ilmentymiä ovat erityisesti nivel- ja hermosto-oireet sekä harvemmin sydän- ja silmäoireet. Suurin osa potilaista paranee täysin terveeksi antibioottihoidon avulla, mutta jopa 10 % borrelioosiin sairastuneista oireilee suositusten mukaisesta hoidosta huolimatta. Pitkittyneen oireilun on ajateltu johtuvan mm. infektion laukaisemasta autoimmuunitaudista tai kroonisesta infektiosta, mutta teorioiden tueksi ei ole kyetty esittämään kiistattomia todisteita. Onkin todennäköistä, että antibioottihoidon jälkeisen oireilun takana on useampia mekanismeja eikä yksi teoria selitä kaikkien potilaiden oireilua. Tässä väitöskirjatyössä on tutkittu hoidonjälkeistä borrelioosia hiirimallin avulla. Varhaisvaiheessa (2 viikkoa infektoinnin jälkeen) annettu antibiootti vähensi hiirten nivelturvotusta ja esti B. burgdorferi – bakteerin kasvun kudoksista otetuista näytteissä. Hoidettu¬jen hiirten B. burgdorferi -spesifiset IgG-luokan vasta-aineet pysyivät kuitenkin koholla ja osasta kudosnäytteistä löytyi B. burgdorferi:n DNA:ta PCR-tutkimuksen avulla. Mikäli hiiret hoidettiin myöhäisessä vaiheessa (yli 18 viikkoa infektoinnista) tulokset olivat muuten samanlaiset, mutta keftriaksoni ei vaikuttanut nivelturvotukseen. Näin hiirissä oli aikaansaatu tilanne, joka on hyvin samankaltainen ihmisen hoitoresistentin borrelia-artriitin kanssa: oireet jatkuvat, mutta taudinaiheuttajaa ei saada esiin. Inflammaatiota vaimentavaa anti-TNF-alphaa on käytetty nivelreuman hoidossa menestyksekkäästi huonosti muuhun hoitoon reagoivilla potilailla ja siitä syystä sen ajateltiin voivan vaikuttaa suotuisasti myös B. burgdorferi -infektoitujen hiirten hoidonjälkeiseen nivelturvotukseen. Sillä ei kuitenkaan ollut vaikutusta nivelturvotukseen, mutta yllättäen hoidon jälkeen osa hiirten kudosnäytteistä osoittautui viljelypositiivisiksi. On siis ilmeistä, että hiirimallissamme osa B. burgdorferi spirokeetoista pystyy välttämään keftriaksonihoidon vaikutuksen joko hakeutumalla elimistössä kudokseen, jossa antibiootin pitoisuus ei nouse riittävän korkeaksi, tai ne kykenevät muuntautumaan metabolisesti inaktiiviin tilaan eikä mikrobilääke yhdessä immuunipuolustuksen kanssa onnistu tappamaan niitä. Jatkotutkimuksissa selvitimme B. burgdorferi - spirokeetan mahdollista piilopaikkaa tutkimalla antibioottihoidon jälkeen useita eri kudoksia PCR-menetelmällä. Tulosten perusteella spirokeetta näyttää suosivan nivelkudosta tai soluja, joita esiintyy nivelessä runsaasti. On kuitenkin edelleen epäselvää, missä muodossa B. burgdorferi –spirokeetat säilyvät kudoksessa antibioottihoidon jälkeen.

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Estudou-se a cinética de crescimento de Borrelia burgdorferi, por um período de 3 meses, utilizando os seguintes oito meios de cultivo : (1) BSK adicionado de soro de coelho, (2) BSK adicionado de soro de suíno, (3) BSK adicionado de soro de suíno + 5 fluorouracil, (4) PMR, (5) CTB, (6) Dubos, (7) Caldo Brucella e (8) BHI. Todos os meios foram preparados assepticamente e mantidos em tubos de ensaio com capacidade para 10 ml. Para cada meio, o inoculo foi padronizado para conter no início 10² espiroquetas para cada 0,1 ml de cultivo. O monitoramento do crescimento foi feito contando-se o total de espiroquetas em 0,1 ml do meio entre lâmina de microscopia e lamínula com dimen sões de 10x30mm, tendo sido utilizado microscópio de campo escuro. A contagem foi realizada durante 14 semanas, tendo sido diária nos primeiros 12 dias e semanal a partir desta data. Houve crescimento de B. burgdorferi em todos meios testados, com melhor performance para três deles: BSK adicionado de soro de coelho, BSK adicionado de soro de suíno + 5 fluorouracil e meio CTB. Observou-se crescimento de B. burgdorferi a partir da 4ª semana, atingindo o platô de crescimento entre a 8ª e 12ª semanas, quando começou a exaustão do meio de cultivo. Formas císticas de B. burgdorferi foram observadas em todos os meios testados.

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Borreliose de Lyme é uma zoonose cosmopolita causada pelo espiroquetídeo Borrelia burgdorferi e tem como vetores carrapatos ixodídeos. Esta espiroqueta acomete diversas espécies de animais domésticos e silvestres, sendo o cão um importante reservatório no ambiente domiciliar. O quadro clínico da doença envolve as articulações, além de causar alterações em vários sistemas do organismo. Foram analisados 143 soros de cães provenientes dos municípios de Seropédica, Itaguaí e do Rio de Janeiro, Estado do Rio de Janeiro, quanto à ocorrência de anticorpos contra B. burgdorferi latu sensu, através de teste de ELISA indireto. Foram encontrados 48,25% de animais soropositivos, sendo 41,9% em Seropédica, 4,9% em Itaguaí e 1,4% no Rio de Janeiro. Os títulos variaram de 1:400 a 1:6400. Cães com menos de um ano apresentaram menor índice de títulos positivos, sendo a diferença significativa. Entre machos e fêmeas, não houve diferença significativa entre os títulos positivos. O resultado encontrado deve servir como alerta para ocorrência de Borrelia sp nas regiões estudadas, considerando a importância da borreliose de Lyme como zoonose emergente.

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Espiroquetas transmitidas por carrapatos são microrganismos de ampla distribuição geográfica e acometem animais silvestres, domésticos e seres humanos. Procedeu-se a análise sorológica de 300 soros de eqüinos onde 58 animais eram do município Ananideua, 61 eram de Belém, 131 de Castanhal e 50 eram do município de Santa Izabel do Pará para Borrelia burgdorferi através do teste ELISA indireto. Não foram observadas diferenças significativas (P < 0,05) entre os municípios, nem quanto à raça, sexo e função dos animais. Um total de 80 (26,7%) animais foram positivos para B. burgdorferi com os títulos de 1:800, 72 (90%) eqüinos; 1:1.600, 6 (7,5%) eqüinos; e 1:3.200, 2 (2,5%) eqüinos. Os resultados observados foram similares aos descritos nos EUA, onde foram relatadas freqüências de soropositivos variando entre 7 e 75% em eqüinos assintomáticos. A presença de anticorpos homólogos contra B. burgdorferi em eqüinos na mesorregião metropolitana de Belém é indicativo da ampla distribuição do agente e da possibilidade de ocorrerem casos humanos deste agente na região.

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Pesquisou-se a presença de anticorpos contra Borrelia burgdorferi latu sensu em cães de áreas rurais de sete municípios do Estado do Rio de Janeiro, pelo ensaio imunoenzimático indireto, associando-se os resultados com a presença de carrapatos nestes animais. de 199 cães examinados, 15,58% estavam positivos, com títulos que variaram de 400 (13,57%) a 1600 (0,5%). Os casos positivos se distribuíram uniformemente nos sete municípios. Não houve diferença estatística (P > 0,05) de soropositivos entre as faixas etárias dos cães acima de seis meses. Carrapatos foram encontrados e coletados em 71 (35,68%) cães, dos quais 24,1% estavam infestados com Amblyomma cajennense, 13,6% com Rhipicephalus sanguineus, 2,5% com Amblyomma aureolatum e 1,5% com Amblyomma ovale. Dos animais soropositivos para B. burgdorferi, 38,7% apresentavam A. cajennense e 22,6% apresentavam R. sanguineus, não havendo, entretanto, correlação positiva entre a presença do carrapato e sorologia positiva.