Epinephrine and norepinephrine affect the cellular morphology, composition, and structure of Gallibacterium anatis biofilm.

Gallibacterium anatis is a Gram-negative bacterium that is a pathogen and part of the microbiome of both domestic and wild birds. It is also the cause of reproductive infections, primarily when birds are stressed. Its pathogenicity has been associated with the expression of virulence factors. The effect of epinephrine (Epi) and norepinephrine (NEpi) hormones on the composition and structure of G. anatis biofilms is evaluated here. Catecholamines induced compaction and fragmentation of biofilms at 24 h. Biofilm amount diminishes (50%) by NEpi. At 48 h, biofilm fragments are immersed in exopolymer material, and the control biofilm shows a high quantity of filamentous cells, not observed with hormones. Enzymatic digestion of biofilm polymers showed increased protein levels in the presence of Epi at 24 or 48 h and NEpi at 24 or 72 h. Epi increased carbohydrate quantity, but NEpi diminished, and DNA quantities diminished at 48 h by Epi. Epi diminishes the expression of proteins in the 70-200 kDa range but increases the expression of secreted proteins. NEpi induces proteolytic activity in the range of 20-110 kDa. A 55 kDa protease was induced at 72 h by both hormones. Gallibacterium anatis biofilm changes could be significant in its dispersion and pathogenesis.