MPL36, a major plasminogen (PLG) receptor in pathogenic Leptospira, has an essential role during infection

Leptospirosis, a zoonosis with worldwide distribution, is caused by pathogenic spirochetes belonging to the genus Leptospira. Bacterial outer membrane proteins (OMPs), particularly those with surface-exposed regions, play crucial roles in pathogen dissemination and virulence mechanisms. Here we characterized the leptospiral Membrane Protein L36 (MPL36), a rare lipoprotein A (RlpA) homolog with a C-terminal Sporulation related (SPOR) domain, as an important virulence factor in pathogenic Leptospira. Our results confirmed that MPL36 is surface exposed and expressed during infection. Using recombinant MPL36 (rMPL36) we also confirmed previous findings of its high plasminogen (PLG)-binding ability determined by lysine residues of the C-terminal region of the protein, with ability to convert bound-PLG to active plasmin. Using Koch’s molecular postulates, we determined that a mutant of mpl36 has a reduced PLG-binding ability, leading to a decreased capacity to adhere and translocate MDCK cell monolayers. Using recombinant protein and mutant strains, we determined that the MPL36-bound plasmin (PLA) can degrade fibrinogen. Finally, our mpl36 mutant had a significant attenuated phenotype in the hamster model for acute leptospirosis. Our data indicates that MPL36 is the major PLG binding protein in pathogenic Leptospira, and crucial to the pathogen’s ability to attach and interact with host tissues during infection. The MPL36 characterization contributes to the expanding field of bacterial pathogens that explore PLG for their virulence, advancing the goal to close the knowledge gap regarding leptospiral pathogenesis while offering a novel potential candidate to improve diagnostic and prevention of this important zoonotic neglected disease.

Delay in the diagnosis and treatment of tuberculosis in prisons in Mato Grosso do Sul, Brazil

ABSTRACT Background: The number of tuberculosis (TB) cases in prisons is higher than that in the general population and has been reported as the most common cause of death in prisons. This study evaluated the delay in the diagnosis and treatment of TB in Brazilian prisons. Methods: A retrospective cohort study was conducted between 2007 and 2015 using data from the five largest male prisons in Mato Grosso do Sul, Brazil. TB case data was collected from the National Database of Notifiable Diseases (SINAN), GAL-LACEN, and prison medical records. The following variables were recorded: prison, year of diagnosis, age, race, education, HIV status, smoking status, comorbidities, number of symptoms, percentage of cures, delay in diagnosis, patient delay, provider delay, laboratory delay, and delay in treatment. Descriptive statistics were used for the variables of interest. Results: A total of 362 pulmonary TB cases were identified. The average time between the first symptom and reporting of data was 94 days. The mean time between symptom onset and laboratory diagnosis was 91 days. The average time from symptom onset to first consultation was 80 days. The time between diagnosis and treatment initiation was 5 days. Conclusions: Delays were significant between reporting of the first symptoms and diagnosis and significantly smaller from the time between notification and start of treatment. Control strategies should be implemented to diagnose cases through active screening, to avoid delays in diagnosis and treatment, and to reduce TB transmission.

Effectiveness of the CoronaVac vaccine in older adults during a gamma variant associated epidemic of covid-19 in Brazil: test negative case-control study

Objective To estimate the effectiveness of the inactivated whole virus vaccine, CoronaVac (Sinovac Biotech), against symptomatic covid-19 in the elderly population of São Paulo state, Brazil during widespread circulation of the gamma variant. Design Test negative case-control study. Setting Community testing for covid-19 in São Paulo state, Brazil. Participants 43 774 adults aged ≥70 years who were residents of São Paulo state and underwent reverse transcription polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 from 17 January to 29 April 2021. 26 433 cases with symptomatic covid-19 and 17 622 test negative controls with covid-19 symptoms were formed into 13 283 matched sets, one case with to up to five controls, according to age, sex, self-reported race, municipality of residence, previous covid-19 status, and date of RT-PCR test (±3 days). Intervention Vaccination with a two dose regimen of CoronaVac. Main outcome measures RT-PCR confirmed symptomatic covid-19 and associated hospital admissions and deaths. Results Adjusted vaccine effectiveness against symptomatic covid-19 was 24.7% (95% confidence interval 14.7% to 33.4%) at 0-13 days and 46.8% (38.7% to 53.8%) at ≥14 days after the second dose. Adjusted vaccine effectiveness against hospital admissions was 55.5% (46.5% to 62.9%) and against deaths was 61.2% (48.9% to 70.5%) at ≥14 days after the second dose. Vaccine effectiveness ≥14 days after the second dose was highest for the youngest age group (70-74 years)­59.0% (43.7% to 70.2%) against symptomatic disease, 77.6% (62.5% to 86.7%) against hospital admissions, and 83.9% (59.2% to 93.7%) against deaths­and declined with increasing age. Conclusions Vaccination with CoronaVac was associated with a reduction in symptomatic covid-19, hospital admissions, and deaths in adults aged ≥70 years in a setting with extensive transmission of the gamma variant. Vaccine protection was, however, low until completion of the two dose regimen, and vaccine effectiveness was observe to decline with increasing age among this elderly population.

Social determinants associated with Zika virus infection in pregnant women

This study aims to describe the sociodemographic determinants associated with exposure to Zika Virus (ZIKV) in pregnant women during the 2015–2016 epidemic in Salvador, Brazil. Methods We recruited women who gave birth between October 2015 and January 2016 to a cross-sectional study at a referral maternity hospital in Salvador, Brazil. We collected information on their demographic, socioeconomic, and clinical characteristics, and evaluated their ZIKV exposure using a plaque reduction neutralization test. Logistic regression was then used to assess the relationship between these social determinants and ZIKV exposure status. Results We included 469 pregnant women, of whom 61% had a positive ZIKV result. Multivariate analysis found that lower education (adjusted Prevalence Rate [aPR] 1.21; 95%CI 1.04–1.35) and food insecurity (aPR 1.17; 95%CI 1.01–1.30) were positively associated with ZIKV exposure. Additionally, age was negatively associated with the infection risk (aPR 0.99; 95%CI 0.97–0.998). Conclusion Eve after controlling for age, differences in key social determinants, as education and food security, were associated with the risk of ZIKV infection among pregnant women in Brazil. Our findings elucidate risk factors that can be targeted by future interventions to reduce the impact of ZIKV infection in this vulnerable population.

Suicide in Brazilian indigenous communities: clustering of cases in children and adolescents by household

ABSTRACT OBJECTIVE To estimate age and sex-specific suicide rates, compare suicide rates between indigenous communities, and quantify the frequency of intrafamilial suicide clustering. METHODS We performed a retrospective cohort study involving 14,666 indigenous individuals in reservations in Dourados, state of Mato Grosso do Sul, Brazil, from 2003 through 2013 using national and local census. RESULTS The overall suicide rate was 73.4 per 100,000 person-years. Adolescent males aged 15-19 and girls aged 10-14 had the highest rates for each sex at 289.3 (95%CI 187.5-391.2) and 85.3 (95%CI 34.9-135.7), respectively. Comparing the largest reservations, Bororo had a higher suicide rate than Jaguapiru (RR = 4.83, 95%CI 2.85-8.16) and had significantly lower socioeconomic indicators including income and access to electricity. Nine of 19 suicides among children under 15 occurred in household clusters. Compared with adult suicides, a greater proportion of child (OR = 5.12, 95%CI 1.89-13.86, p = 0.001) and adolescent (OR = 3.48, 95%CI 1.29-9.44, p = 0.017) suicides occurred within household clusters. CONCLUSIONS High rates of suicide occur among children and adolescents in these indigenous reservations, particularly in poor communities. Nearly half of child suicides occur within household clusters. These findings underscore the need for broad public health interventions and focused mental health interventions in households following a suicide.

Rat infestation associated with environmental deficiencies in an urban slum community with high risk of leptospirosis transmission / Infestação por roedores associada a fatores ambientais numa comunidade carente com alto risco de transmissão da leptospirose / Infestación por roedores asociada a factores ambientales en una comunidad sin recursos con alto riesgo de transmisión de la leptospirosis

Abstract: We analyzed environmental factors that provide food, water and harborage to rodents and the risk of household rodent infestation in a slum community with a high risk of leptospirosis transmission. Detailed environmental surveys were performed in 221 households. Multivariate regression models evaluated the association between rodent infestation and socioeconomic status and environmental attributes obtained from Geographical Information System surveys. The general household infestation rate was 45.9%. Rattus norvegicus signs were the most prevalent, present in 74% of the infested households. The risk for rodent infestation was associated with environmental factors supporting harborage for rats, such as dilapidated fences/walls (OR: 8.95; 95%CI: 2.42-33.12) and households built on an earthen slope (OR: 4.68; 95%CI: 2.23-9.81). An increase of 1 meter from the nearest sewer was associated with a 3% (95%CI: 1%-5%) decrease in the risk of rodent infestation. A lack of sanitation where poor people live provides factors for rat infestation and could the target of educational interventions.

Resumo: O estudo analisou fatores ambientais que facilitam a presença de alimento, água e abrigo para roedores e risco de infestação por roedores numa comunidade com alto risco de transmissão da leptospirose. Foram realizados inquéritos ambientais detalhados em 221 domicílios. Modelos de regressão multivariada avaliaram a associação entre infestação por roedores e nível socioeconômico e atributos ambientais obtidos através de inquéritos com Sistemas de Informação Geográfica. O estudo mostrou uma taxa global de 45,9% de infestação domiciliar. Sinais de Rattus norvegicus eram os mais prevalentes, presentes em 74% dos domicílios infestados. O risco de infestação por roedores esteve associado a fatores ambientais que forneciam abrigo aos ratos, tais como cercas e muros dilapidados (OR: 8,95; IC95%: 2,42-33,12) e domicílios construídos diretamente sobre encostas (OR: 4,68; IC95%: 2,23-9,81). Cada incremento de um metro de distância a partir do esgoto mais próximo esteve associado a uma diminuição de 3% (IC95%: 1%-5%) no risco de infestação por roedores. A falta de saneamento básico nos locais de moradia das famílias pobres facilita a infestação por ratos e é alvo prioritário para intervenções educativas.

Resumen: El estudio analizó factores ambientales que facilitan la presencia de alimento, agua y abrigo para roedores y el riesgo de infestación por roedores en una comunidad sin recursos con alto riesgo de transmisión de la leptospirosis. Se realizaron encuestas ambientales detalladas en 221 domicilios. Los modelos de regresión multivariada evaluaron la asociación entre infestación por roedores, nivel socioeconómico y características ambientales, obtenidos a través de encuestas con Sistemas de Información Geográfica. El estudio mostró una tasa global de un 45,9% de infestación domiciliaria. Los indicios de Rattus norvegicus eran los más prevalentes, presentes en un 74% de los domicilios infestados. El riesgo de infestación por roedores estuvo asociado a factores ambientales que proporcionaban abrigo a las ratas, tales como cercas y muros derruidos (OR: 8,95; IC95%: 2,42-33,12) y domicilios construidos directamente sobre pendientes (OR: 4,68; IC95%: 2,23-9,81). Cada incremento de un metro de distancia, a partir del alcantarillado más próximo, estuvo asociado a una disminución de un 3% (IC95%: 1%-5%) en el riesgo de infestación por roedores. La falta de saneamiento básico en las viviendas de las familias pobres facilita la infestación por ratas y es el objetivo prioritario para intervenciones educativas.

Puerperal brain cryptococcoma in an HIV-negative woman successfully treated with fluconazole: a case report

Cryptococcus spp. cerebral abscesses are uncommon in immunocompetent subjects. The recommended induction treatment is the administration of amphotericin B plus flucytosine combined with resection for lesions ≥3cm. In this paper, we describe an HIV-negative woman diagnosed with a large cryptococcoma in the immediate postpartum period. The lesion was not resected, and due to amphotericin B intolerance, she received an extended course of fluconazole monotherapy. There was no disease recurrence during the 4 years of follow-up. The abrupt onset of her symptoms following delivery suggests that she developed a postpartum immune reconstitution syndrome. This case also demonstrates that in specific situations fluconazole monotherapy can be attempted in immunocompetent patients with cryptococcoma.

Surveillance for leptospirosis in the Americas, 1996-2005: a review of data from ministries of health / Vigilancia de la leptospirosis en la Región de las Américas, de 1996 al 2005: análisis de los datos de los ministerios de salud

Objective. To characterize current leptospirosis reporting practices in the Americas.Methods. Information was collected from the official websites of national ministries ofhealth from the Americas region and two international organizations; personal communications;and three international morbidity databases. For all sources other than the morbiditydatabases, the review was limited to official reports citing clinically suspected and laboratoryconfirmed leptospirosis cases or deaths during the period 1996–2005.Results. A total of 73 out of 1 644 reports met the selection criteria and were included inthe analysis. Published leptospirosis data were available from half of the countries/sovereignterritories (24 out of 48), and 18 of them had mandatory notification policies for leptospirosis.The sum of the median number of leptospirosis cases notified annually by the 24 countries/territories was 4 713.5, but just three countries (Brazil, Costa Rica, and Cuba) accounted for83.1% (3 920 cases) of the notifications. Eight (16.7%) countries reported deaths due to leptospirosis.The sum of the median number of deaths reported annually for the eight countrieswas 380, but 349 (91.8%) were reported by Brazil.Conclusions. Notification practices in the Americas for leptospirosis are limited. Therefore,the numbers of cases and deaths reported are not representative for the region. The lack ofleptospirosis data for many countries/territories may reflect weaknesses in certain aspects ofnational surveillance systems, including mandatory reporting policies, clinical laboratory infrastructurefor performing case confirmation, and capacity to collect reported cases. Improvedsurveillance of leptospirosis cases and deaths in the Americas is needed to allow monitoring ofregional epidemiological patterns and to estimate the burden of this important disease.

Detección de Leptospira santarosai y L. kirschneri en bovinos: nuevos aislados con potencial impacto en producción bovina y salud pública / Detection of Leptospira santarosai and L. kirschneri in cattle: new isolates with potential impact in bovine production and public health

Bovine leptospirosis causes high economic losses in cattle mainly due to reproductive failure, as well as representing public health risk. Since the last century, antibody titers against several Leptospira serovars have been detected by the microscopic agglutination test (MAT) in Mexico. With the exception of very few cases, the presence of serovars causing leptospirosis in cattle and other animal species has not been demonstrated by isolation in Mexico, and in such cases characterization had to be done abroad by complex and slow immunological approaches, by comparison with a number of reference strains. The present study was conducted to perform the molecular characterization of Leptospira isolates by multiple locus sequencing typing (MLST). A hundred and ninety seven sera and kidneys samples were collected immediately after slaughter, from grazing cattle coming from the south-eastern states of Mexico. Anti-Leptospira antibodies were detected by the MAT and kidneys were inoculated into EMJH and Fletcher's specific medium. A seropositivity of 60.4% (119 out of 197), with titers from 1:100 up to 1:3 200 was detected. Four isolates (2.03%), referred as CAL4, CAL6, CAL7 and MOCA45, were characterized by serology, ribotyping and MLST as L. kirschneri serovar Grippotyphosa; L. interrogans serovar Hardjo; L. santarosai serovar Mini and L. santarosai serovar Tarassovi, respectively. With the exception of serovar Hardjo, the three other isolates belong to serovars and species not previously isolated in Mexico. These findings make it necessary to evaluate the potential distribution of such serovars among cattle and their role on animal production and public health.

La leptospirosis bovina causa grandes pérdidas económicas a la ganadería por problemas reproductivos y también es un riesgo de salud pública. En México, desde el siglo pasado se ha registrado la presencia de anticuerpos contra serovariedades de Leptospira por la técnica de aglutinación microscópica (AM), en bovinos y otras especies animales. En muy pocos casos, la enfermedad fue demostrada por el aislamiento de Leptospira, y en tales casos, su caracterización se basó en métodos inmunológicos lentos que requirieron la comparación con cepas de referencia y que fueron realizados fuera de México. En el presente trabajo se realizó la caracterización molecular mediante la secuenciación de locus múltiples (MLST), de aislados de Leptospira obtenidos de riñones de bovinos recolectados en rastro, procedentes de las zonas Golfo y sur de México. Se obtuvieron muestras de suero y riñones de 197 bovinos para realizar la AM, y el cultivo en medios específicos EMJH y Fletcher. Se detectó una seropositividad del 60.4% (119 de 197), con títulos desde 1:100 hasta 1:3,200 y se obtuvieron cuatro aislados de Leptospira (2.03%), denominados CAL4, CAL6, CAL7 y MOCA45. Los aislados fueron caracterizados por serología, ribotipificación y MLST, como L. kirschneri serovariedad Grippotyphposa; L. interrogans serovariedad Hardjo; L. santarosai serovariedad Mini y L. santarosai serovariedad Tarassovi, respectivamente. A excepción de la serovariedad Hardjo, los aislados pertenecen a especies y serovariedades no aisladas anteriormente en la República Mexicana, esto sugiere la necesidad de evaluar su diseminación entre bovinos y su potencial efecto en la producción animal y en la salud pública.

Espacialização da leptospirose em Aracaju, Estado de Sergipe, no período de 2001 a 2007 / Geographical distribution of leptospirosis in Aracaju, State of Sergipe from 2001 to 2007

INTRODUÇÃO: A leptospirose, enfermidade causada por uma espiroqueta patogênica do gênero Leptospira, é uma das zoonoses mais difundidas no mundo, considerada um importante problema de saúde pública. Este trabalho tem como objetivo descrever o padrão espacial da leptospirose na Cidade de Aracaju, no período de 2001 a 2007, buscando identificar as áreas de risco para ocorrência da leptospirose. MÉTODOS: Utilizou-se a razão de Kernel, que consiste na criação de uma razão entre duas superfícies, para visualizar a superfície de risco da doença, onde no numerador coloca-se os casos, georreferenciados para setor censitário, e no denominador o kernel da população dessas áreas. Através deste método, foi possível delimitar áreas de maior densidade de casos, e compará-las visualmente com fator socioeconômico, como renda média. RESULTADOS: Comparando os períodos de chuva com os períodos de seca, verificou-se que não ocorre a presença de padrão espacial semelhante nos dois períodos, não coincidindo com as áreas consideradas de maior risco para ocorrência da doença. Através dos parâmetros estabelecidos, neste estudo, foi permitido verificar a importância da aplicação de técnicas de análise espacial na área de saúde pública. CONCLUSÕES: O kernel se mostrou uma ferramenta útil na obtenção de uma análise global da situação epidemiológica da leptospirose em Aracaju, o que viabiliza sua utilização pelas secretarias de saúde municipal e estadual.

INTRODUCTION: Leptospirosis, a disease caused by pathogenic spirochetes of the genus Leptospira, is one of the most widespread zoonoses in the world and is considered an important public health problem. This paper aims to describe the spatial pattern of leptospirosis in the City of Aracaju from 2001 to 2007 in an effort to identify areas at risk for leptospirosis. METHODS: We used the ratio of Kernel, which represents the ratio between two surfaces, to visualize the surface of disease risk. The numerator corresponds to the number of cases geocoded to the census tract, and the denominator of the kernel corresponds to the population of these areas. Using this method, the areas with the highest density of cases were delineated and compared visually with socioeconomic factors, such as average income. RESULTS: The spatial pattern was different in periods of rain compared with periods of drought and did not coincide with the areas considered most at risk for the disease. This study revealed the importance of applying spatial analysis techniques in the field of public health. CONCLUSIONS: These findings indicate that the kernel is a useful tool for obtaining a comprehensive review of the epidemiology of leptospirosis in Aracaju, which supports the kernel's use by the municipal health departments and by the state.

Leptospirosis serosurvey in bovines from Brazilian Pantanal using IGG ELISA with recombinant protein LipL32 and microscopic agglutination test

This investigation was carried out in Brazilian Pantanal: region with important biodiversity. This region's climatic conditions, hydrology and geomorphology as well as the existence of great variety of wild species favor the maintenance of the Leptospira in the environment. The aim of this study was to evaluate IgG ELISA with recombinant protein LipL32 in comparison with microscopic agglutination test (MAT) and additionally contribute to the knowledge of the distribution of the one of most important worldwide zoonotic infection, assessing the seropositivity of bovine leptospirosis in beef cattle herds of Brazilian Pantanal, an important ecological preserved area, where cattle constitute not only the most important economic resource but also the major activity compatible of the conservation of natural resource of the region. Out of 282 samples of cattle serum analyzed, 143 (50.71 percent) were positive in MAT. The serovar Hardjo (genotypic Hardjoprajitno and Hardjobovis), Wolffi and Ballum showed the largest frequency of reactive samples. In the IgG ELISA rLipL32, 161 samples (57.09 percent) were positive. This result was higher than obtained by MAT (p<0.001). The sensitivity of the ELISA test was 99.30 percent and the specificity was 86.33 percent, based on the MAT. This test was shown to be a more sensitive, specific and accurate test for the diagnosis of bovine leptospirosis compared to the MAT.

Este estudo foi realizado no Pantanal brasileiro: região que apresenta importante biodiversidade. As condições de clima, hidrologia e geomorfologia dessa região, bem como a existência de grande variedade de espécies animais silvestres, favorecem a manutenção da Leptospira no meio ambiente. O objetivo desse estudo foi avaliar o ELISA IgG com proteína recombinante LipL32 em comparação com a soroaglutinação microscópica (SAM) para o diagnóstico sorológico de Leptospira. Adicionalmente, contribuir para o conhecimento da distribuição da leptospirose bovina, uma das mais importantes zoonoses mundialmente distribuída. Foi avaliada a soropositividade para essa bactéria em rebanhos bovinos de corte da região do Pantanal, uma área onde o bovino constitui não apenas o recurso econômico mais importante, como também a principal atividade econômica compatível com a conservação dos recursos naturais da região. Das 282 amostras de soro bovino analisadas, 143 (50,71 por cento) foram positivas na SAM. O sorovar Hardjo (genótipos Hardjoprajitno e Hardjobovis), Wolffi e Ballum apresentaram freqüências altas de amostras reativas. No IgG ELISA rLipL32, 161 amostras (57,09 por cento) foram positivas, apresentando esse teste uma maior soropositividade em relação à SAM (p<0,001). A Sensibilidade do ELISA em comparação com a SAM foi de 99,30 por cento e a especificidade de 86,33 por cento. O IgG ELISA rLipL32 mostrou ser um teste sensível, específico e de alta acurácia para o diagnóstico de leptospirose bovina.

Factors associated with Leptospira sp infection in a large urban center in northeastern Brazil

Leptospirosis is a zoonotic disease that has emerged to cause epidemics in urban communities in developing countries. However, little is known about the infection in the general population. A seroprevalence survey was performed on a random sample of 1,390 subjects in Salvador, Brazil. Data on environmental and socioeconomic factors were collected. The microagglutination test of serum samples was used to show any prior Leptospira infection. The overall seroprevalence was 12.4 percent. Among the seropositive individuals, 111 (61 percent) had high titers for serovars of the Icterohaemorrhagiae serogroup. Seroprevalence increased with age and was similar for males and females. A positive correlation between Leptospira infection and low educational level was found. These findings indicate that a significant proportion of this urban population is exposed to pathogenic Leptospira. Public health actions for leptospirosis control will need to target not only the traditional groups at risk of infection with severe forms of this disease, but also the general population that is at risk.

A leptospirose é uma zoonose que tem emergido causando epidemias em comunidades urbanas de países em desenvolvimento. Entretanto, pouco é conhecido sobre infecção na população geral. Inquérito de soroprevalência foi realizado em amostra randômica de 1.390 indivíduos de Salvador, Brasil. Dados sobre fatores ambientais e sócio-econômicos foram coletados. Teste de Microaglutinação de amostras de soro foi utilizado para evidenciar infecção anterior por Leptospira. Soroprevalência global foi 12,4 por cento. Entre os soropositivos, 111 (61 por cento) tinham altos títulos para os sorovares do serogrupo Icterohaemorrhagiae. A soroprevalência aumentou com a idade e foi similar entre homens e mulheres. Encontrou-se correlação positiva entre infecção por Leptospira e baixo nível educacional. Os achados indicam que significativa proporção dessa população urbana está exposta a Leptospira patogênica. Ações de saúde pública para controle desta doença necessitarão ter como alvo não só os tradicionais grupos de risco associados às suas formas graves, como também a população geral sob risco.

Frequency of antiphospholipid antibodies in patients with infectious diseases using three different ELISA methods

OBJETIVO: O ensaio de enzyme-linked immunosorbent assay (ELISA) para a pesquisa de anticorpos anticardiolipina (aCL) é o mais importante teste para o diagnóstico da síndrome antifosfolipídica (SAF). Entretanto esse teste também pode ser positivo em algumas doenças infecciosas. Tem sido sugerido que a detecção de anticorpos para uma mistura de fosfolípides ou para b2-glicoproteína I (b2-GP I) teria uma maior especificidade para a SAF que o teste de ELISA-padrão para aCL. O objetivo do presente estudo é comparar a especificidade de três testes para anticorpos antifosfolípides (aFL) em pacientes com doenças infecciosas. MÉTODOS: Anticorpos antifosfolípides foram pesquisados por três técnicas de ELISA, ou seja, o teste-padrão para aCL, o kit de ELISA APhL® e o teste para anti-b2-GP I em pacientes com doenças infecciosas, tais como sífilis (69), leptospirose (33) e Calazar (30). RESULTADOS: A freqüência de positividade de aFL da classe IgG em pacientes com sífilis, leptospirose e Calazar foi de 13/69 (19 por cento), 9/33 (27 por cento) e 2/30 (6 por cento), respectivamente, com o ELISA-padrão para aCL versus 1/69 (1,4 por cento), 0/33 (0 por cento) e 0/30 (0 por cento) com o kit de ELISA APhL®. A positividade do isotipo IgM foi de 10/69 (14 por cento), 4/33 (12 por cento) e 1/30 (3 por cento), respectivamente, com o ELISA-padrão para aCL, e 1/69 (1,4 por cento), 0/33 (0 por cento) e 0/30 (0 por cento) com o kit de ELISA APhL®. Anticorpos da classe IgG contra b2GPI foram detectados em 14/69 casos de sífilis (20 por cento), 6/33 casos de leptospirose (18 por cento) e 16/30 casos de Calazar (53 por cento). Assim, o kit de ELISA APhL® apresentou uma maior especificidade: 97 por cento (95 por cento CI: 92 por cento-99 por cento) comparado com 81 por cento (95 por cento CI: 74 por cento-87 por cento) para o teste de aCL-padrão e 72 por cento (95 por cento CI: 64 por cento-79 por cento) para o teste de anticorpos anti-b2 GPI. CONCLUSÕES: O kit de ELISA APhL® parece ser m...

Monoclonal antibodies against an outer membrane protein from pathogenic Leptospira

Foram obtidos dois hibridomas secretores de anticorpos monoclonais (MAbs) que reagem com uma lipoproteína (LipL32) da membrana externa de leptospiras patogênicas. Para a produção dos hibridomas, células do baço de camundongos BALB/c, imunizados com LipL32 recombinante (rLipL32), foram fusionadas com células SP2/O-Ag14, selecionadas em meio HAT e testadas em ELISA indireto. Um dos MAbs secretados pelos hibridomas é do isotipo IgG2b e o outro do isotipo IgM. A especificidade dos MAbs foi confirmada em ELISA indireto e immunoblotting usando rLipL32 purificada, Escherichia coli (E. coli) expressando LipL32 e sorovares patogênicos e saprófitas. Os dois MAbs reagiram com a maioria dos sorovares patogênicos e não reagiram com sorovares saprófitas. Os MAbs possuem potencial para uso em testes de diagnóstico de leptospirose.

Monoclonal antibodies against an outer membrane protein from pathogenic Leptospira

Two hybridomas secreting monoclonal antibodies (MAbs) that react with a lipoprotein (LipL32) of the outer membrane of pathogenic Leptospira were obtained. For hybridoma production, spleen cells from BALB/c mice imunized with recombinant LipL32 (rLipL32) were fused to SP2/O-Ag14 cells, selected in HAT medium and screened in an indirect ELISA. One MAb produced was of the IgG2b isotype and the other was an IgM. MAbs specificity was confirmed by indirect ELISA and immunoblotting using purified rLipL32 and whole-cell antigen preparations from Escherichia coli (E. coli) expressing LipL32 and from pathogenic and non-pathogenic serovars. Both Mabs reacted with most of the pathogenic serovars tested and none reacted with non-pathogenic Leptospira. The MAbs described have potential for use in diagnostic tests for leptospirosis.

Foram obtidos dois hibridomas secretores de anticorpos monoclonais (MAbs) que reagem com uma lipoproteína (LipL32) da membrana externa de leptospiras patogênicas. Para a produção dos hibridomas, células do baço de camundongos BALB/c, imunizados com LipL32 recombinante (rLipL32), foram fusionadas com células SP2/O-Ag14, selecionadas em meio HAT e testadas em ELISA indireto. Um dos MAbs secretados pelos hibridomas é do isotipo IgG2b e o outro do isotipo IgM. A especificidade dos MAbs foi confirmada em ELISA indireto e immunoblotting usando rLipL32 purificada, Escherichia coli (E. coli) expressando LipL32 e sorovares patogênicos e saprófitas. Os dois MAbs reagiram com a maioria dos sorovares patogênicos e não reagiram com sorovares saprófitas. Os MAbs possuem potencial para uso em testes de diagnóstico de leptospirose.

Monoclonal antibodies against an outer membrane protein from pathogenic Leptospira

Two hybridomas secreting monoclonal antibodies (MAbs) that react with a lipoprotein (LipL32) of the outer membrane of pathogenic Leptospira were obtained. For hybridoma production, spleen cells from BALB/c mice imunized with recombinant LipL32 (rLipL32) were fused to SP2/O-Ag14 cells, selected in HAT medium and screened in an indirect ELISA. One MAb produced was of the IgG2b isotype and the other was an IgM. MAbs specificity was confirmed by indirect ELISA and immunoblotting using purified rLipL32 and whole-cell antigen preparations from Escherichia coli (E. coli) expressing LipL32 and from pathogenic and non-pathogenic serovars. Both Mabs reacted with most of the pathogenic serovars tested and none reacted with non-pathogenic Leptospira. The MAbs described have potential for use in diagnostic tests for leptospirosis.

Foram obtidos dois hibridomas secretores de anticorpos monoclonais (MAbs) que reagem com uma lipoproteína (LipL32) da membrana externa de leptospiras patogênicas. Para a produção dos hibridomas, células do baço de camundongos BALB/c, imunizados com LipL32 recombinante (rLipL32), foram fusionadas com células SP2/O-Ag14, selecionadas em meio HAT e testadas em ELISA indireto. Um dos MAbs secretados pelos hibridomas é do isotipo IgG2b e o outro do isotipo IgM. A especificidade dos MAbs foi confirmada em ELISA indireto e immunoblotting usando rLipL32 purificada, Escherichia coli (E. coli) expressando LipL32 e sorovares patogênicos e saprófitas. Os dois MAbs reagiram com a maioria dos sorovares patogênicos e não reagiram com sorovares saprófitas. Os MAbs possuem potencial para uso em testes de diagnóstico de leptospirose.

Síndrome da meningite asséptica por enterovírus e Leptospira sp em crianças de Salvador, Bahia / Aseptic meningitis syndrome due to enterovirus and Leptospira sp in children of Salvador, Bahia

Objetivando verificar a freqüência de enterovírus (EV), leptospiras e arbovírus como agentes causais da síndrome da meningite asséptica (SMA), em períodos näo-epidêmicos, e comparar os pacientes com e sem diagnóstico etiológico determinado, foram selecionados 112 pacientes de idade entre 3 meses e 15 anos, com suspeita clínica de SMA, referenciados para Hospital Couto Maia, especializado em Doenças Infecciosas e Parasitárias (Salvador, Bahia), Em 44,6 por cento (n=50) a etiologia foi determinada: enterovírus em 37,7 por cento (n=42) dos casos, pelo teste de PCR Amplicor, por cultura do líquor e/ou de fezes; a Leptospira sp. em 7,1 por cento (n=8), pelo método da micro-aglutinaçäo, e nenhum caso de arbovírus foi detectado (inibiçäo da hemaglutinaçäo passiva). Entre os 14 enterovírus dos 22 isolados, foram identificados seis diferentes sorotipos, sendo o Echovirus-4 predominante (27,2 por cento; 6/22) entre outros (Coxsackie B2, B3, B6 e B9; EV 71). Conclui-se que, os enterovírus foram os agentes mais freqüentes, e que a leptospirose deve ser lembrada no diagnóstico diferencial da SMA. Uma vez que as características clínicas e liquóricas dos pacientes dos grupos com e sem determinaçäo do agente etiológico foram semelhantes, pode-se supor que o diagnóstico presuntivo de SMA é de provável etiologia viral ou pela leptospira

Characterization of protective and non-protective surface membrane carbohydrate epitopes of Schistosoma mansoni

We have produced a number of monoclonal antibodies, protective and non-protective, which recognize a complex of schistosomula antigens, including the 38 kDa antigen. Eight different protective and non-protective monoclonal antibodies, varying in isotypes, were used in the binding assays. Lectin inhibition studies suggested that the monoclonal antibodies probably recognized carbohydrate epitopes on the antigen(s). Immunoprecipitation studies showed that at least two of the monoclonal antibodies recognized different epitopes on the same molecule. Additionally, we tested for monoclonal antibody binding after the antigens were treated with; 1) proteases, 2) periodate, 3) various exo- and endoglycosidases, 4) mild acid hydrolysis. We also tested for binding of the antibodies to keyhole limpet hemocyanin (KLH). Using the 8 monoclonal antibodies as probes, we were able to define at least 4 different carbohydrate epitopes related to the protective monoclonal antibodies, and at least one epitope which is seen by the non-protective antibodies. The epitope seen by the non-protective antibodies was shown to be cross-reactive with epitopes on KLH. These results demonstrate the importance of epitope mapping studies for any defined vaccine.