Journal of Microbiology

Journal Article

Gallibacterium elongation factor-Tu possesses amyloid-like protein characteristics, participates in cell adhesion, and is present in biofilms: Jaqueline López-Ochoa , J. Fernando Montes-García , Candelario Vázquez , Patricia Sánchez-Alonso , Victor M. Pérez-Márquez , Patrick J. Blackall , Sergio Vaca , Erasmo Negrete-Abascal; J. Microbiol. 2017;55(9):745-752. Published online September 2, 2017; DOI: https://doi.org/10.1007/s12275-017-7077-0

Abstract: 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 F149T. 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.

Research Support, Non-U.S. Gov't

NOTE] Involvement of Curli Fimbriae in the Biofilm Formation of Enterobacter cloacae: Sung-Min Kim , Hee-Woo Lee , Yeh-Wan Choi , Shuk-Ho Kim , Je-Chul Lee , Yoo-Chul Lee , Sung-Yong Seol , Dong-Taek Cho , Jungmin Kim; J. Microbiol. 2012;50(1):175-178. Published online February 27, 2012; DOI: https://doi.org/10.1007/s12275-012-2044-2

Abstract: In this study, we examined the biofilm forming ability, the mRNA expression of curli genes and the morphologies of curli fimbriae and biofilms in clinical isolates of Enterobacter cloacae. The csgBA operon was found in 11 (78.6%) of the 14 isolates. The ability of E. cloacae isolates to form biofilms was significantly correlated with the mRNA expression level of the csgA and csgD genes. The curli protein fimbriae appeared as tangled fibers and the curli-proficient strain formed mature biofilms. Our data suggest that the expression of the curli fimbriae play an important role in biofilm formation in E. cloacae.

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