Nutritional interference for phenotypic biofilm quantification in Aeromonas spp. isolates containing the fla gene

The Aeromonas genus has several virulence factors associated with the development of diseases in aquatic organisms, leading to losses in aquaculture. One of these factors is the flagella's formation which allows the biofilm's formation that provides the microorganisms a greater pathogenicity, greater protection to certain substances such as antibiotics. The aim of the study was to verify the presence of the fla gene, related to biofilm production in isolates of Aeromonas spp. from fishes and also to determine the best quantification condition of phenotypic biofilm production in vitro. Polymerase Chain Reactions were performed to obtain the amplification of the region comprising the fla gene. To determine the best condition for the production biofilm, the microplate adhesion test was carried out under different concentrations of TSB broth and it combined with glucose. Of the 43 isolates of Aeromonas spp. analyzed, 28 were positive for the fla gene and, in the quantification of the biofilm, all these were able to form biofilm in the TSB broth without dilution and without addition of glucose, being this the best condition tested. It was observed that the isolates of Aeromonas spp. analyzed have potential for biofilm formation, and hence potential for virulence.