Bacterial autoaggregation

Abstract

Many bacteria, both environmental and pathogenic, exhibit the property of autoaggregation. In autoaggregation (sometimes also called autoagglutination or flocculation), bacteria of the same type form multicellular clumps that eventually settle at the bottom of culture tubes. Autoaggregation is generally mediated by self-recognising surface structures, such as proteins and exopolysaccharides, which we term collectively as autoagglutinins. Although a widespread phenomenon, in most cases the function of autoaggregation is poorly understood, though there is evidence to show that aggregating bacteria are protected from environmental stresses or host responses. Autoaggregation is also often among the first steps in forming biofilms. Here, we review the current knowledge on autoaggregation, the role of autoaggregation in biofilm formation and pathogenesis, and molecular mechanisms leading to aggregation using specific examples.

Coaggregation properties of trimeric autotransporter adhesins

“…Auto‐ or coaggregation is often a step on the developmental pathway leading to biofilm formation (Trunk et al, 2018). TAAs are known to mediate the formation of biofilm (Leo et al, 2011; Mil‐Homens & Fialho, 2012; Okaro, Green, Mohapatra, & Anderson, 2019).…”

In vitro and in vivo efficacy of combinations of colistin and different endolysins against clinical strains of multi-drug resistant pathogens

“…An aggregative effect was previously described in the endolysin phi12 isolated from a S. aureus bacteriophage, although the cause of the effect was unknown 41 . Autoaggregation has been suggested to occur in environmental stress caused by toxins, antibiotics, predation or low nutrients 42 .…”

Autotransporters Drive Biofilm Formation and Autoaggregation in the Diderm Firmicute Veillonella parvula

“…In addition to Hag1, a YadA-like autotransporter identified from the related species V. atypica involved in interspecies interactions ( 22 ), VtaA represents the second Veillonella protein described which is involved in adhesion and the first involved in abiotic surface adhesion and autoaggregation in diderm firmicutes. Beyond the potential impact on Veillonella niche colonization, aggregation capacity is known to contribute to bacterial protection from environmental stresses or host responses ( 23 ), promotion of host colonization ( 24 ), or pathogenesis ( 25 ) in various bacterial species. VtaA is homologous to the Brucella suis trimeric autotransporter BtaF.…”