Leptospirosis is a neglected disease of man and animals that affects nearly half a million people annually and causes considerable economic losses. Current human vaccines are inactivated whole-cell preparations (bacterins) of Leptospira spp. that provide strong homologous protection yet fail to induce a cross-protective immune response. Yearly boosters are required, and serious side-effects are frequently reported so the vaccine is licensed for use in humans in only a handful of countries. Novel universal vaccines require identification of conserved surface-exposed epitopes of leptospiral antigens. Outer membrane β-barrel proteins (βb-OMPs) meet these requirements and have been successfully used as vaccines for other diseases. We report the evaluation of 22 constructs containing protein fragments from 33 leptospiral βb-OMPs, previously identified by reverse and structural vaccinology and cell-surface immunoprecipitation. Three-dimensional structures for each leptospiral βb-OMP were predicted by I-TASSER. The surface-exposed epitopes were predicted using NetMHCII 2.2 and BepiPred 2.0. Recombinant constructs containing regions from one or more βb-OMPs were cloned and expressed in Escherichia coli. IMAC-purified recombinant proteins were adsorbed to an aluminium hydroxide adjuvant to produce the vaccine formulations. Hamsters (4-6 weeks old) were vaccinated with 2 doses containing 50 – 125 μg of recombinant protein, with a 14-day interval between doses. Immunoprotection was evaluated in the hamster model of leptospirosis against a homologous challenge (10 – 20× ED50) with L. interrogans serogroup Icterohaemorrhagiae serovar Copenhageni strain Fiocruz L1-130. Of the vaccine formulations, 20/22 were immunogenic and induced significant humoral immune responses (IgG) prior to challenge. Four constructs induced significant protection (100%, P < 0.001) and sterilizing immunity in two independent experiments, however, this was not reproducible in subsequent evaluations (0 – 33.3% protection, P > 0.05). The lack of reproducibility seen in these challenge experiments and in other reports in the literature, together with the lack of immune correlates and commercially available reagents to characterize the immune response, suggest that the hamster may not be the ideal model for evaluation of leptospirosis vaccines and highlight the need for evaluation of alternative models, such as the mouse.
Lis teriosis is an under-diagnosed and under-reported infection; however, listeriosis is not a compulsorily notifi able disease in Brazil. We provide an overview of the rates of listeriosis in the United States of America (USA), Europe, Latin America, and Brazil during the past decade. We also report a case of miscarriage caused by listeriosis in which there was no suspicion of this infection. This overview and the case we report serve as reminders of the often-neglected threat of listeriosis and its potential to cause miscarriage while highlighting the necessity of recognizing listeriosis as a compulsorily notifi able disease in Brazil.
Objetivo: descrever casos confirmados, isolamento social, internações, óbitos, ocorrência e distribuição demográfica dos casos de novo Coronavírus em Pelotas, até o dia 10 de setembro de 2020. Método: estudo epidemiológico, descritivo, retrospectivo e documental. Foram utilizados dados secundários provenientes dos boletins epidemiológicos da Prefeitura de Pelotas. Resultados: medidas mais brandas de isolamento social em julho e agosto, parecem ter implicado na maior elevação das curvas de casos confirmados, internação e óbito. Maior testagem da população, pode ser relacionado com o aumento da taxa de infecção observada nestes meses. Em relação à distribuição populacional, identifica-se que o sexo feminino tem taxa de infecção maior que o masculino, entretanto, os homens internaram mais que as mulheres e apresentam maior taxa de mortalidade. Conclusões: no período analisado, os meses de agosto e setembro obtiveram maior número de casos confirmados pelo novo coronavírus na cidade de Pelotas.
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