Publications by authors named "K E Avelar"

Article Synopsis
  • The research focuses on leptolysin, a metalloproteinase secreted by the bacteria Leptospira, which may aid in the bacteria's ability to cause disease by degrading host immune system components.
  • A portion of patients with mild leptospirosis showed antibodies against leptolysin, indicating its expression during infection; experiments with knockout strains demonstrated that leptolysin helps the bacteria resist serum from the host.
  • Although a mutant strain lacking leptolysin was still virulent in hamsters, it resulted in lower bacterial levels in the kidneys, suggesting the need for further investigation into the role of metalloproteinases in Leptospira pathogenicity.
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Leptospirosis is a zoonotic disease with significant global impact and a challenging diagnosis. The utilization of adequately validated rapid tests is relevant for the opportune identification of the disease and for reduction in fatality rates. The present study analyzes the accuracy and reliability of the Dual Path Platform (DPP) assay -produced in Brazil by the Oswaldo Cruz Foundation (Fiocruz)- for diagnosing leptospirosis.

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Leptospirosis diagnosis by MAT requires antibody levels that are typically present only after the first week of symptoms, many days after infection. To improve testing capacity and to develop a fast and reliable solution for the diagnosis of this disease in the first few days after clinical manifestations, the National Reference Laboratory for Leptospirosis/WHO Collaborating Center in Brazil implemented a duplex molecular method by qPCR for human samples for the detection of the gene L32, conserved in pathogenic spp. In this paper, we describe the overall performance of this protocol in the first 3 months as a standard routine.

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Sphingomyelin is a major constituent of eukaryotic cell membranes, and if degraded by bacteria sphingomyelinases may contribute to the pathogenesis of infection. Among spp., there are five sphingomyelinases exclusively expressed by pathogenic leptospires, in which Sph2 is expressed during natural infections, cytotoxic, and implicated in the leptospirosis hemorrhagic complications.

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The zoonotic disease leptospirosis is caused by pathogenic species of the genus and was recently included in the list of Neglected Diseases by the World Health Organization. Leptospirosis burden is estimated to have over a million human cases and cause 60 thousand deaths annually, in addition to its economic impact and veterinary concern. The microscopic agglutination test (MAT), recommended by the World Health Organization, exhibits reduced sensitivity at the beginning of the disease, in addition to being technically difficult.

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