Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Faculdade de Medicina, Universidade Federal Fluminense, Rio de Janeiro, Brazil.
Diagn Microbiol Infect Dis. 2019 Aug;94(4):337-341. doi: 10.1016/j.diagmicrobio.2019.02.009. Epub 2019 Feb 20.
Staphylococcus epidermidis is one of the leading causes of bloodstream infections, particularly in premature neonates, and biofilm formation is a major virulence factor. We characterized biofilm formation by 50 S. epidermidis neonatal isolates under osmotic stress and evaluated the expression of biofilm-associated genes. Phenotypical analyses of biofilm production were performed in culture medium with or without addition of NaCl or glucose. In control medium (no additions), most isolates (84%) were nonproducers or weak biofilm producers. Growth in NaCl-containing medium increased the number of moderate/strong producers, and this increase was even greater in medium containing glucose. Most of the protein-enriched biofilms (60%) could be observed only during growth in glucose, whereas 50% of the polysaccharide-enriched biofilms were observed during growth in NaCl. Studies that evaluate the conditions used to characterize biofilm production are important to help us understand the dynamics of this important virulence factor in S. epidermidis and their impact on neonatal infections.
表皮葡萄球菌是血流感染的主要病原体之一，尤其是在早产儿中，生物膜形成是主要的毒力因子。我们在渗透压应激下对 50 株表皮葡萄球菌新生儿分离株的生物膜形成进行了特征描述，并评估了与生物膜相关基因的表达。在含有或不含有 NaCl 或葡萄糖的培养基中进行生物膜产生的表型分析。在对照培养基（无添加物）中，大多数分离株（84%）是非生产者或弱生物膜生产者。在含有 NaCl 的培养基中生长增加了中等/强生产者的数量，而在含有葡萄糖的培养基中增加更多。只有在葡萄糖生长过程中才能观察到大多数富含蛋白质的生物膜（60%），而在 NaCl 生长过程中则观察到 50%的富含多糖的生物膜。评估生物膜产生特征所使用的条件的研究对于帮助我们理解表皮葡萄球菌中这种重要毒力因子的动态及其对新生儿感染的影响非常重要。
