In vitro evidence for immune evasion activity by human plasmin associated to pathogenic Leptospira interrogans

Leptospirosis is a widespread re-emerging zoonosis of human and veterinary concern. It has been shown that virulent leptospires protect themselves against the host`s innate immune system, a strategy that allows the bacteria to reach immunologically safe environments. Although extensive studies on host pathogen interactions have been performed, little is known on how leptospires deal with host immune attack. In a previous work, we demonstrated the ability of leptospires to bind human plasminogen (PLC), that after treatment with activators, conferred plasmin (PLA) activity on the bacteria surface. In this study, we show that the PLA activity associated to the outer surface of Leptospira could interfere with the host immune attack by conferring some evasion advantage during infection. We demonstrate that PLA-coated leptospires interfere with complement Ob and IgG depositions on the bacterial surface, probably through the degradation of these components, thus diminishing opsonization process. Similar decrease on the deposition was observed when normal and immune sera from patients diagnosed with leptospirosis were employed as a source of IgG. We believe that decreasing opsonization by PLA generation might be an important aspect of the leptospiral immune escape strategy and survival. To our knowledge, this is the first proteolytic activity of plasmin associated-Leptospira related to anti-opsonic properties reported to date. (C) 2011 Elsevier Ltd. All rights reserved.

Tick toxicosis in a dog bitten by Ornithodoros brasiliensis

Ticks are hematophagous parasites of people and animals and are a public health hazard in several countries. They are vectors of infectious diseases; in addition, the bite of some ticks, mainly from the Ornithodoros genus, may lead to local lesions and systemic illness, referred to as tick toxicosis. In this report, we describe a dog bitten by Ornithodoros brasiliensis, popularly known as the mouro tick. The main clinical findings were disseminated skin rash, pruritus, mucosal hyperemia, lethargy, and fever. Laboratory abnormalities 48 hours after the bites occurred included mild nonregenerative anemia, eosinophilia, basophilia, increased serum creatine kinase activity, increased serum C-reactive protein concentration, and prolonged coagulation times. Tick-borne pathogens were not detected by PCR analysis or serologic testing, supporting the diagnosis of a noninfectious syndrome due to tick bite, compatible with tick toxicosis.

Survey for Tick-Borne Zoonoses in the State of Espirito Santo, Southeastern Brazil

Blood samples collected from 201 humans, 92 dogs, and 27 horses in the state of Espirito Santo, Brazil, were tested by polymerase chain reaction, indirect immunofluorescence assays, and indirect enzyme-linked immunosorbent assay for tick-borne diseases (rickettsiosis, ehrlichiosis, anaplasmosis, borreliosis, babesiosis). Our results indicated that the surveyed counties are endemic for spotted fever group rickettsiosis because sera from 70 (34.8%) humans, 7 (7.6%) dogs, and 7 (25.9%) horses were reactive to at least one of the six Rickettsia species tested. Although there was evidence of ehrlichiosis (Ehrlichia canis) and babesiosis (Babesia cams vogeli, Theileria equi) in domestic animals, no human was positive for babesiosis and only four individuals were serologically positive for E. canis. Borrelia burgdorferi-serologic reactive sera were rare among humans and horses, but encompassed 51% of the canine samples, suggesting that dogs and their ticks can be part of the epidemiological cycle of the causative agent of the Brazilian zoonosis, named Baggio-Yoshinari Syndrome.

Lsa63, a newly identified surface protein of Leptospira interrogans binds laminin and collagen IV

Leptospira interrogans is the etiological agent of leptospirosis, a zoonotic disease that affects populations worldwide. We have identified in proteomic studies a protein that is encoded by the gene LIC10314 and expressed in virulent strain of L. interrogans serovar Pomona. This protein was predicted to be surface exposed by PSORT program and contains a p83/100 domain identified by BLAST analysis that is conserved in protein antigens of several strains of Borrelia and Treponema spp. The proteins containing this domain have been claimed antigen candidates for serodiagnosis of Lyme borreliosis. Thus, we have cloned the LIC10314 and expressed the protein in Escherichia coli BL21-SI strain by using the expression vector pAE. The recombinant protein tagged with N-terminal hexahistidine was purified by metal-charged chromatography and characterized by circular dichroism spectroscopy. This protein is conserved among several species of pathogenic Leptospira and absent in the saprophytic strain L. biflexa. We confirm by liquid-phase immunofluorescence assays with living organisms that this protein is most likely a new surface leptospiral protein. The ability of the protein to mediate attachment to ECM components was evaluated by binding assays. The leptospiral protein encoded by LIC10314, named Lsa63 (Leptospiral surface adhesin of 63 kDa), binds strongly to laminin and collagen IV in a dose-dependent and saturable fashion. In addition, Lsa63 is probably expressed during infection since it was recognized by antibodies of serum samples of confirmed-leptospirosis patients in convalescent phase of the disease. Altogether, the data suggests that this novel identified surface protein may be involved in leptospiral pathogenesis. (C) 2009 The British Infection Society. Published by Elsevier Ltd. All rights reserved.

Plasminogen Acquisition and Activation at the Surface of Leptospira Species Lead to Fibronectin Degradation

Pathogenic Leptospira species are the etiological agents of leptospirosis, a widespread disease of human and veterinary concern. In this study, we report that Leptospira species are capable of binding plasminogen (PLG) in vitro. The binding to the leptospiral surface was demonstrated by indirect immunofluorescence confocal microscopy with living bacteria. The PLG binding to the bacteria seems to occur via lysine residues because the ligation is inhibited by addition of the lysine analog 6-aminocaproic acid. Exogenously provided urokinase-type PLG activator (uPA) converts surface-bound PLG into enzymatically active plasmin, as evaluated by the reaction with the chromogenic plasmin substrate D-Val-Leu-Lys 4-nitroanilide dihydrochloridein. The PLG activation system on the surface of Leptospira is PLG dose dependent and does not cause injury to the organism, as cellular growth in culture was not impaired. The generation of active plasmin within Leptospira was observed with several nonvirulent high-passage strains and with the nonpathogenic saprophytic organism Leptospira biflexa. Statistically significant higher activation of plasmin was detected with a low-passage infectious strain of Leptospira. Plasmin-coated virulent Leptospira interrogans bacteria were capable of degrading purified extracellular matrix fibronectin. The breakdown of fibronectin was not observed with untreated bacteria. Our data provide for the first time in vitro evidence for the generation of active plasmin on the surface of Leptospira, a step that may contribute to leptospiral invasiveness.

Localized Abdominal Idiopathic Lipodystrophy

Localized loss of subcutaneous tissue can occur after panniculitis, injections of corticosteroids and other drugs, or associated with infectious, autoimmune or neurologic diseases. The "idiopathic lipoatrophies" are a group of poorly characterized diseases, with focal disappearance of subcutaneous fat, and usually the thighs, abdomen or the ankles are affected. Three subtypes have been described based on clinical presentation: lipoatrophia semicircularis, annular lipoatrophy of the ankles and centrifugal lipodystrophy. We describe a 52-year-old female patient who developed a localized atrophy of the abdominal areas over a period of 3 months without any inflammatory signs over the evolution of the disease. The patient denied any previous local trauma or medication of any type. The atrophy stabilized, showing no progression over the last 6 years. The histopathological examination was normal except for the absence of subcutaneous fat, although the biopsy was taken down to the fascia. There was no clinical or serologic evidence of autoimmune diseases and laboratory testing for Borrelia burgdorferi infection was negative. Other causes of localized lipoatrophies were excluded and the final diagnosis was localized idiopathic lipodystrophy. Our patient is the second report on an abdominal lipodystrophy, with no previous inflammatory signs, absence of subcutaneous fat and no associated pathogenic factor. There is no established treatment for idiopathic lipodystrophy, and the lesions do not tend to resolve spontaneously.

Coreia - Em Busca do Diagnóstico!

Introdução: A coreia, isolada ou associada a outros distúrbios do movimento, pode serforma de apresentação de diversas patologias. A história clínica e o exame objectivo sugerem o diagnóstico e orientam a investigação da generalidade das situações de coreia, sendo a sua etiologia identificada na maioria dos casos. Relato de caso: Adolescente do sexo feminino, 14 anos, residente em Angola, com movimentos involuntários dos membros e face, interpretados como coreia e discinésia oro-facial, e hipomobilidade do membro superior direito com cinco dias de evolução associada a labilidade emocional. Sem história sugestiva de doença estreptocócica, infeccções recentes ou exposição a fármacos. Avaliação laboratorial, incluindo função tiroideia, ceruloplasmina sérica, exame citoquímico e imunoelectroforese do líquor, sem alterações relevantes. Pesquisa de tóxicos negativa. Ressonância magnética crânio-encefálica e electroencefalograma normais. Evidência ecocardiográfica de insuficiência mitral ligeira sem aspectos sugestivos de cardite reumática. Exame bacteriológico do exsudado faríngeo negativo e doseamento de anticorpos anti-estreptococo negativo. Apesar destes resultados realizou penicilina benzatínica. Do restante estudo infeccioso destaca-se serologia compatível com infecção a Borrelia burgdorferi sem envolvimento neurológico. O doseamento de anticorpos anti-N-methyl-D-aspartate receptor (ac anti-NMDAR) foi positivo no soro. Iniciou tratamento sintomático com carbamazepina e haloperidol com resolução das queixas. A segunda amostra para pesquisa de ac anti-NMDAR no líquor e sangue foi negativa. Conclusões: O facto de não haver confirmação de doença estreptocócica prévia, não nos permite assumir a coreia de Sydenham, causa mais frequente de coreia em pediatria. Como a restante investigação não foi conclusiva deverá esta doente ser seguida a longo prazo; talvez a evolução nos venha o dar o diagnóstico final.

Norovírus Associated Encephalopathy

clinical presentation is self limited. It is classified into five groups (genogroups I through V). There are numerous reports of neurologic complications, namely afebrile seizures, but only two reports of associated encephalopathy. Case Report: A 12 month old girl with previous history of a pneumonia treated with amoxicillin-clavulanic acid and clarythromycin, presented in our emergency department with strabismus, ataxia for 3 days, later associated with vomiting and diarrhea. On admission she had ataxia and an episode of strabismus, but her later neurologic exam was normal. Laboratory data revealed: 10,9 g/dL hemoglobin, 11.200/μL leukocytes, 29,1% neutrophils and 65,2% lymphocytes, 488.000/μL platelets and negative CRP. The brain MRI showed middle ear, maxillary sinus and ethmoidal opacification, with no other abnormalities. During the first day of admission she had a tonic (?) seizure for 20 minutes. CSF analysis showed 5,6 cells/μL, 100% lymphocytes, 80 mg/dL glucose and 154,1 mg/dL protein. The EEG revealed short duration paroxystic activity located to the vertex. She was treated with acyclovir, ciprofloxacin, cefthriaxone and phenytoin. Her symptoms resolved by the third day of admission. Blood samples were tested for numerous pathogens, including serology for Borrelia, which was positive for IgG but negative for IgM. Fecal sample analysis revealed positive PCR for norovirus, although it was negative in CSF samples. IL-6 was measured in the CSF and was negative (5,8 pg/mL). She had a history of recurrent otitis media and pernieal candidiasis, which led to a detailed immune function study, which showed Immunology tests revealed diminished IgA (< 0,244 g/L) and absent antibody response to vaccinations. Since she was only 13 months old when she was tested, only follow up will determine the relevance of these values. Follow up at two years of age showed no delays and a normal development. Conclusion: Norovirus encephalitis is a rare entity, although gastrointestinal infection with this agent is relatively common. Here we present a case of a probable norovirus associated encephalopathy, although PCR for norovirus was negative in CSF samples and there was no CSF cytokine increase. It was not associated with adverse neurologic outcome and so far her development is normal, unlike the evolution described in previous case reports.

Síndrome de Stevens-Johnson e Ibuprofeno

Introdução: A síndrome de Stevens-Johnson é uma doença rara com mortalidade de 1 a 5% e morbilidade significativa. Ocorre na sequência de uma reacção de hipersensibilidade imuno-mediada com susceptibilidade individual associada a factores genéticos. Pode ser desencadeada por agentes infecciosos, mas na maior parte dos casos o factor desencadeante é a exposição a fármacos. Caso clínico: Criança de 3 anos, previamente saudável, internada por febre alta, exantema papulovesicular generalizado com predomínio no tronco, dorso e face, enantema e hiperémia conjuntival. Posteriormente verificou-se coalescência das lesões cutâneas com evolução para necrose e descamação. Tinha adicionalmente erosões da mucosa oral, estomatite, edema e eritema dos lábios, períneo e balanite. Fotofobia, hiperémia conjuntival, edema palpebral, exsudado ocular sem sinéquias e córnea sem lesões. Duas semanas antes tinha sido medicado pela primeira vez com ibuprofeno e na admissão hospitalar realizou uma nova administração. Nega ingestão de outros fármacos. PCR para vírus do grupo herpes nas lesões, exames culturais negativos e serologias para Mycoplasma pneumoniae, Borrelia burgdoferi, vírus da hepatite B, Epstein-Barr e citomegalovírus negativos. TASO e anti-DNaseB sem alterações. IFI para vírus respiratórios negativa. Posteriormente identificou-se enterovírus por PCR nas fezes de que se aguarda cultura viral. Foi interrompida a administração de ibuprofeno e realizada terapêutica de suporte com fluidoterapia endovenosa, nutrição parentérica, analgesia sistémica e tópica. Manteve febre durante 10 dias, registando-se regressão progressiva da sintomatologia com melhoria das lesões ao fim de 3 semanas. Programou-se seguimento para rastreio de complicações cutâneo-mucosas e oftalmológicas e estudo de alergias medicamentosas. Comentários: O diagnóstico da síndrome de Stevens-Johnson é clínico e, em caso de dúvida, histológico, suportado por história de exposição a fármacos ou intercorrência infecciosa. A ingestão de ibuprofeno pela primeira vez com agravamento após a reexposição ao fármaco leva-nos a suspeitar ser esta a etiologia mais provável. Contudo, a identificação de enterovírus não permite excluir este agente como interveniente na doença.

Hipersonolência Diurna. Narcolepsia, Qual a Etiologia?

Introdução: A narcolepsia é uma doença do sono REM com desregulação do ciclo de sono-vigília, consequente sonolência diurna e eventual associação a alucinações hipnagógicas, paralisia do sono e cataplexia. A sua prevalência é de 0,05 a 0,02% no adulto mas desconhecida na idade pediátrica. Caso clínico: Criança de seis anos, previamente saudável com sonolência excessiva até 18 horas/dia e discinésia oromandibular, desequilíbrio na marcha e movimentos coreiformes dos membros superiores. Duas semanas antes realizara vacinação para a gripe pandémica. Registou-se ainda hiperfagia diurna e nocturna durante cinco dias com resolução espontânea, episódios de cataplexia perante riso e alterações emocionais e tremor da cabeça e dos membros superiores com melhoria clínica progressiva após oito dias. Realizou RMN-CE e EEG sem alterações. O exame líquido céfalo-raquidiano e PCR para painel de vírus herpes, Mycoplasma pneumoniae e enterovírus negativas. Nesta fase realizou polissonografia com teste de latências múltiplas do sono (TLMS) sem alterações. Exame cultural do exsudado faríngeo, TASO e anticorpo AntiDnase B negativos. Da exaustiva investigação que realizou apresentava serologias ELISA e WB compatíveis com infecção por Borrelia burdorferi, pelo que cumpriu ceftriaxone 14 dias. Serologias para influenza A mostraram IgM 39 UA/mL com IgG 194 UA/mL com segunda amostra com IgM 43 UA/mL e IgG 162 UA/mL (VR IgM<20;IgG<20). O estudo da autoimunidade revelou ANA 1/320, anticorpos anticardiolipina e antinucleares extraíveis negativos. Restantes autoanticorpos e doseamento de complemento normal. Anticorpos Anti-NMDA e VKCG negativos. Doseamento de hipocretina muito diminuído com HLA DR2 e DQB1*0602 presentes. A polissonografia com TLMS, sete meses após a primeira, confirmou sonolência excessiva com quatro inícios do sono REM sugestivos de narcolepsia. Faz terapêutica com metilfenidato, a sonolência diurna diminuiu e cumpre o seu horário escolar sem limitações. Comentários: O diagnóstico de narcolepsia foi sugerido pela clínica e confirmado pelo teste de latências múltiplas. O valor de hipocretina diminuído pode sugerir uma etiologia autoimune. Uma infecção como a borreliose ou a vacinação prévia para H1N1, responsabilizada por outros casos de narcolepsia podem ter sido desencadeantes de uma alteração imunitária responsável pela doença, nesta criança com a susceptibilidade HLA DR2 e DBQ1*0602.

Profile of patients with Baggio-Yoshinari Syndrome admitted at "Instituto de Infectologia Emilio Ribas"

The aim of this study was to evaluate the epidemiological, clinical and laboratorial profile of patients with Baggio-Yoshinari Syndrome (BYS), who underwent internment at the Instituto de Infectologia Emilio Ribas in São Paulo, Brazil, during the period from July 1990 to July 2006. BYS is a new Brazilian tick-borne disease caused by Borrelia burgdorferi sensu lato microorganisms that resembles features of Lyme disease (LD), except for its epidemiological, clinical and laboratorial particularities. From 60 patients' records with positive serology to B. burgdorferi done by ELISA and Western-blotting methods, 19 cases were diagnosed as having BYS, according to criteria adopted at LIM-17 HCFMUSP, the Brazilian Reference Laboratory for the research of BYS. The other 41 remaining patients displayed miscellaneous infections or auto-immune processes. The beginning of symptoms in BYS group varied from one day to six years, from the onset of the disease. Four of 19 patients were included in acute disease stage, and 15 in latent. General unspecific symptoms were identified in almost all cases, with high frequencies of fever (78.9%) and lymphadenomegaly (36.8%). Six patients had skin lesions (31.5%); six arthralgia or arthritis (31.5%) and eight neurological symptoms (42%). Interestingly, two patients showed antibodies directed to B. burgdorferi exclusively in cerebrospinal fluid. Since BYS is a new emergent Brazilian zoonosis and its diagnosis is sometimes complex, all the new knowledge about BYS must be scattered to Brazilian Medical specialists, aiming to teach them how to diagnose this amazing tick-borne disease and to avoid its progression to chronic irreversible sequels

Amplification of the flgE gene provides evidence for the existence of a Brazilian borreliosis

INTRODUCTION: The symptoms of Brazilian borreliosis resemble the clinical manifestations of Lyme disease (LD). However, there are differences between the two in terms of epidemiological and laboratory findings. Primers usually employed to diagnose LD have failed to detect Borrelia strains in Brazil. OBJECTIVE: We aimed to identify the Brazilian Borrelia using a conserved gene that synthesizes the flagellar hook (flgE) of Borrelia burgdorferi sensu lato. METHOD: Three patients presenting with erythema migrans and positive epidemiological histories were recruited for the study. Blood samples were collected, and the DNA was extracted by commercial kits. RESULTS: The gene flgE was amplified from DNA of all selected patients. Upon sequencing, these positive samples revealed 99% homology to B. burgdorferi flgE. CONCLUSION: These results support the existence of borreliosis in Brazil. However, it is unclear whether this borreliosis is caused by a genetically modified B. burgdorferi sensu stricto or by a new species of Borrelia spp.

Recurrent uveitis, cystoid macular edema and pericarditis in Lyme disease.

Lyme disease has been associated with many systemic and ocular complications. The authors' patient, a 26-year-old man, developed recurrent pars planitis with two episodes of acute pericarditis. Extensive medical investigations were negative except for a highly positive western blot for Borrelia burgdorferi. Specific antibiotic treatment for Lyme disease was followed by a long lasting period without any relapse.

Coexistence of antibodies to tick-borne agents of babesiosis and Lyme borreliosis in patients from Cotia county, State of São Paulo, Brazil

This paper reports a case of coinfection caused by pathogens of Lyme disease and babesiosis in brothers. This was the first case of borreliosis in Brazil, acquired in Cotia County, State of São Paulo, Brazil. Both children had tick bite history, presented erythema migrans, fever, arthralgia, mialgia, and developed positive serology (ELISA and Western-blotting) directed to Borrelia burgdorferi G 39/40 and Babesia bovis antigens, mainly of IgM class antibodies, suggestive of acute disease. Also, high frequencies of antibodies to B. bovis was observed in a group of 59 Brazilian patients with Lyme borreliosis (25.4%), when compared with that obtained in a normal control group (10.2%) (chi-square = 5.6; p < 0.05). Interestingly, both children presented the highest titers for IgM antibodies directed to both infective diseases, among all patients with Lyme borreliosis.

Neuroborréliose, méningo-encéphalite verno-estivale et neurosyphilis [Neuroborreliosis, tick-borne encephalitis and neurosyphilis].

Infections affecting frequently the nervous system include Lyme disease, tick-borne encephalitis and syphilis. These three most dreaded neuro-infectious diseases observed in Switzerland are discussed, based on diagnostic criteria, screening testing, and treatments modalities. Neuroborreliosis and neurosyphilis are bacterial infectious diseases treatable by antibiotics, whereas the treatment of tick-borne encephalitis, a viral disease, is only based on preventive vaccination.