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The meningococcal autotransporter AutA is implicated in autoaggregation and biofilm formation
Author(s) -
Arenas Jesús,
Cano Sara,
Nijland Reindert,
Dongen Vérène,
Rutten Lucy,
Ende Arie,
Tommassen Jan
Publication year - 2015
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.12581
Subject(s) - biology , biofilm , virulence , microbiology and biotechnology , gene , virulence factor , dna , bacteria , bacterial genetics , western blot , extracellular , genetics , escherichia coli
Summary Autotransporters ( AT s) are proteins secreted by G ram‐negative bacteria that often play a role in virulence. Eight different AT s have been identified in N eisseria meningitidis , but only six of them have been characterized. AutA is one of the remaining AT s. Its expression remains controversial. Here, we show that the aut A gene is present in many neisserial species, but its expression is often disrupted by various genetic features; however, it is expressed in certain strains of N . meningitidis . By sequencing the autA gene in large panels of disease isolates and W estern blot analysis, we demonstrated that AutA expression is prone to phase variation at AAGC nucleotide repeats located within the DNA encoding the signal sequence. AutA is not secreted into the extracellular medium, but remains associated with the bacterial cell surface. We further demonstrate that AutA expression induces autoaggregation in a process that, dependent on the particular strain, may require extracellular DNA ( eDNA ). This property influences the organization of bacterial communities like lattices and biofilms. In vitro assays evidenced that AutA is a self‐associating AT that binds DNA . We suggest that AutA ‐mediated autoaggregation might be particularly important for colonization and persistence of the pathogen in the nasopharynx of the host.