Barbosa Júnia Oliveira, Rossoni Rodnei Dennis, Vilela Simone Furgeri Godinho, de Alvarenga Janaína Araújo, Velloso Marisol dos Santos, Prata Márcia Cristina de Azevedo, Jorge Antonio Olavo Cardoso, Junqueira Juliana Campos
Department of Biosciences and Oral Diagnosis, Univ Estadual Paulista/UNESP, São José dos Campos, São Paulo, Brazil.
Embrapa Gado de Leite, Juiz de Fora, Minas Gerais, Brazil.
PLoS One. 2016 Mar 2;11(3):e0150457. doi: 10.1371/journal.pone.0150457. eCollection 2016.
Streptococcus mutans and Candida albicans are found together in the oral biofilms on dental surfaces, but little is known about the ecological interactions between these species. Here, we studied the effects of S. mutans UA159 on the growth and pathogencity of C. albicans. Initially, the effects of S. mutans on the biofilm formation and morphogenesis of C. albicans were tested in vitro. Next, we investigate the influence of S. mutans on pathogenicity of C. albicans using in vivo host models, in which the experimental candidiasis was induced in G. mellonella larvae and analyzed by survival curves, C. albicans count in hemolymph, and quantification of hyphae in the host tissues. In all the tests, we evaluated the direct effects of S. mutans cells, as well as the indirect effects of the subproducts secreted by this microorganism using a bacterial culture filtrate. The in vitro analysis showed that S. mutans cells favored biofilm formation by C. albicans. However, a reduction in biofilm viable cells and inhibition of hyphal growth was observed when C. albicans was in contact with the S. mutans culture filtrate. In the in vivo study, injection of S. mutans cells or S. mutans culture filtrate into G. mellonella larvae infected with C. albicans increased the survival of these animals. Furthermore, a reduction in hyphal formation was observed in larval tissues when C. albicans was associated with S. mutans culture filtrate. These findings suggest that S. mutans can secrete subproducts capable to inhibit the biofilm formation, morphogenesis and pathogenicity of C. albicans, attenuating the experimental candidiasis in G. mellonella model.
变形链球菌和白色念珠菌共同存在于牙齿表面的口腔生物膜中，但关于这两种菌之间的生态相互作用却知之甚少。在此，我们研究了变形链球菌UA159对白色念珠菌生长和致病性的影响。首先，在体外测试了变形链球菌对白色念珠菌生物膜形成和形态发生的影响。接下来，我们使用体内宿主模型研究了变形链球菌对白色念珠菌致病性的影响，在该模型中，在大蜡螟幼虫中诱导实验性念珠菌病，并通过生存曲线、血淋巴中白色念珠菌计数以及宿主组织中菌丝的定量分析进行分析。在所有测试中，我们评估了变形链球菌细胞的直接作用，以及使用细菌培养滤液评估了该微生物分泌的副产物的间接作用。体外分析表明，变形链球菌细胞促进了白色念珠菌生物膜的形成。然而，当白色念珠菌与变形链球菌培养滤液接触时，观察到生物膜活细胞减少且菌丝生长受到抑制。在体内研究中，将变形链球菌细胞或变形链球菌培养滤液注射到感染白色念珠菌的大蜡螟幼虫中可提高这些动物的存活率。此外，当白色念珠菌与变形链球菌培养滤液相关联时，在幼虫组织中观察到菌丝形成减少。这些发现表明，变形链球菌可以分泌能够抑制白色念珠菌生物膜形成、形态发生和致病性的副产物，减轻大蜡螟模型中的实验性念珠菌病。
