An Optimized Approach to Measure Ag43-Mediated Autoaggregation in DH5α Escherichia coli

Abstract

Autoaggregation is mediated by surface-expressing proteins or secreted macromolecules. This process can be observed by the clumping of bacteria in the bottom of the liquid culture, commonly exhibited by a variety of bacterial strains, including Escherichia coli. A common surface protein that mediates E. coli autoaggregation is Antigen 43 (Ag43), an autotransporter belonging to the Type 5 subtype “a” secretion system. The self-interaction of Ag43 facilitates autoaggregation, which is essential for biofilm formation and bacterial pathogenicity. The autoaggregation assay described in this method paper provides an optimized approach to monitor the autoaggregation ability of DH5α E. coli cells expressing Ag43 to help further investigate the role of Ag43 in the self-interaction of E. coli.