Aderência, invasão e indução de apoptose por estreptococos do grupo B em células epiteliais respiratórias A549

• Autor(a) principal: Costa, Andréia Ferreira Eduardo da
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/16288
• topic: Group B streptococci (GBS); Epithelial cells; Acidic vacuoles; Apoptosis; Estreptococos do grupo B (EGB); Células epiteliais; Vacúolos acídicos; Apoptose; Estreptococo; Células epiteliais; Apoptose; Células Adesão; Vacúolos; CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA::BIOLOGIA E FISIOLOGIA DOS MICROORGANISMOS

Group B streptococci (GBS), mainly serotype III, is a major cause of neonatal pneumonia, sepsis and meningitis. Virulence potential of GBS strains may determine the outcome of host colonization or infection. Because the lung constitutes a first step in GBS systemic invasion processes, we have investigates the adherence and invasion mechanisms of GBS-III isolates to human lung epithelial cell line (A549). Thus, the main objective of this study was to evaluate the ability of adhesion and invasion of GBS strains serotype III (90356-liquor and 80340-vagina) with A549 lung epithelial cells, intracellular bacterial persistence, fusion with acidic compartments, cytotoxic potential, and induction of apoptosis. The strains showed ability to adhere and invade the epithelial A549 cells; GBS 90356-liquor isolated from a patient showed a more efficient adherence and invasion properties than GBS-III 80340 isolated from vagina (P<0,05). Both strains showed persistent intracellular viability without replication into A549 cells up to 24h incubation. In addition, we found that GBS are able to promote cellular vacuolization and persisted viable inside acidic vacuoles, suggesting lysosome-phagosome fusion. The GBS 90356-líquor also showed higher cytotoxicity when compared with 80340-vagina strain. The present work describe for first time by flow cytometry that GBS induces apoptosis in respiratory epithelium and be an important mechanism for the development of acute cellular injury and bacterial pathogenesis.