Aderência, invasão e persistência intracelular de estreptococos do grupo B em células epiteliais respiratórias A549

• Autor(a) principal: Pereira, Camila Serva
• Data de Publicação: 2010
• 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/1/14395
• topic: Streptococcus agalactiae; Epithelial cells; Acidic vacuoles; Intracellular persistence; Streptococcus agalactiae; Células epiteliais; Vacúolos acídicos; Persistência intracelular; CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA

Group B Streptococcus (GBS) commonly colonizes healthy asymptomatic adults, yetunder certain circumstances displays the ability to invade host tissues, evade the immune system and cause serious invasive disease. Consequently, GBS remains the major cause of neonatal pneumonia, sepsis and meningitis. However, the pathogenesis of this infection is poorly understood. The serotype V is frequently associated with invasive diseases in non-pregnant adults and the second most prevalent in pregnant women. The aim of this work was to study the adherence; invasion and persistence intracellular of the GBS serotype V (88641-vagina/carriers and 90186-blood/patient) in epithelial cells A549. All GBS strains showed ability to adhere and invade the epithelial A549 cells, but GBS 90186-blood was more invasive than the vagina isolate (P<0,001). Both strains persisted intracellular, but without replicating into the A549 cells. Only 90186-blood strain survived within epithelial cells even after a 24h incubation (P<0,05). Fusion of epithelial lysosomes with bacteria containing phagocytic vacuoles was observed in A549 cells treated with Lysotracker Grenn DND-26 for all strains tested. Our data indicate for the first time that viable strains of serotype V remain within acidic epithelial vacuoles. Interestingly, the 90186-blood strain induced cellular vacuolization and 88641-vagina strain caused cell death after 7h incubation. Lastly, our results increase our knowledge about cellular events of phagocytosis and pathogeneses of GBS diseases.