Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Puebla, 72560, Mexico.
Carrera de Biología, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, Estado de México, 54090, Mexico.
J Microbiol. 2017 Sep;55(9):745-752. doi: 10.1007/s12275-017-7077-0. Epub 2017 Sep 2.
Gallibacterium, which is a bacterial pathogen in chickens, can form biofilms. Amyloid proteins present in biofilms bind Congo red dye. The aim of this study was to characterize the cell-surface amyloid-like protein expressed in biofilms formed by Gallibacterium strains and determine the relationship between this protein and curli, which is an amyloid protein that is commonly expressed by members of the Enterobacteriaceae family. The presence of amyloid-like proteins in outer membrane protein samples from three strains of G. anatis and one strain of Gallibacterium genomospecies 2 was evaluated. A protein identified as elongation factor-Tu (EF-Tu) by mass spectrometric analysis and in silico analysis was obtained from the G. anatis strain F149. This protein bound Congo red dye, cross-reacted with anti-curli polyclonal serum, exhibited polymerizing properties and was present in biofilms. This protein also reacted with pooled serum from chickens that were experimentally infected with G. anatis, indicating the in vivo immunogenicity of this protein. The recombinant EF-Tu purified protein, which was prepared from G. anatis 12656-12, polymerizes under in vitro conditions, forms filaments and interacts with fibronectin and fibrinogen, all of which suggest that this protein functions as an adhesin. In summary, EF-Tu from G. anatis presents amyloid characteristics, is present in biofilms and could be relevant for the pathogenesis of G. anatis.
鸡源性细菌加氏菌能够形成生物膜，生物膜中的淀粉样蛋白结合刚果红染料。本研究旨在对加氏菌生物膜中表达的细胞表面淀粉样蛋白进行表征，并确定该蛋白与卷曲相关蛋白（一种常见于肠杆菌科成员的淀粉样蛋白）之间的关系。评估了三株鸡加氏菌和一株加氏菌基因组种 2 菌株的外膜蛋白样品中是否存在淀粉样蛋白。通过质谱分析和计算机分析从鸡加氏菌菌株 F149 中获得一种被鉴定为延伸因子-Tu（EF-Tu）的蛋白质。该蛋白与刚果红染料结合，与抗卷曲多克隆血清发生交叉反应，具有聚合特性，存在于生物膜中。该蛋白还与用鸡加氏菌感染的实验鸡的混合血清发生反应，表明该蛋白具有体内免疫原性。从加氏菌 12656-12 中制备的重组 EF-Tu 纯化蛋白在体外条件下聚合，形成纤维并与纤维连接蛋白和纤维蛋白原相互作用，所有这些都表明该蛋白作为一种黏附素发挥作用。综上所述，鸡加氏菌的 EF-Tu 具有淀粉样特征，存在于生物膜中，可能与加氏菌的发病机制有关。
