Ação do extrato etanólico da Hymenaea martiana na produção de biofilme e aderência de Aeromonas spp.

Abstract

The use of herbal products in animal production has shown to be promising because they are natural products, biodegradable and with antimicrobial activity against several pathogens, including fish. The objective of this work was to test the action of the crude ethanolic extract (CEE) of the Hymenaea martiana leaf on the formation and consolidation of the in vitro biofilm, its performance on the adhesion factors produced by Aeromonas spp. and to evaluate its toxicity, proposing an ex vivo model, using as substrate Nile Tilapia epithelium (Oreochromis niloticus) cultivated. The bacterial samples were submitted to a molecular test to detect five possible genes (aer-aerolysin, lip-lipase, ahy-elastase, fla- flagellin and ast-enterotoxins) involved in the production of virulence factors and in the formation of biofilms by the microorganism studied. The isolates were classified in strong, moderate and weak biofilm formers through the Elisa reader, after staining of gentian violet. They were analyzed in vitro against the bactericidal action of the extract and then to test the potential of the extract in the formation and consolidation of the biofilm of the aeromonas. Important factors such as capsule production and motility of the isolates were observed in tests such as red congo and motility assay respectively to understand the relation of genotypic factors to phenotypic responses. In the ex vivo evaluation, the action of the extract on its toxicity was observed with naked eye and optical microscope, presence of A. spp. adhered to the skin of tilapia. and possible morphological changes occurred. Regarding the results: The isolates presented seventeen different genetic combinations besides absence, in three isolates of the studied genes. This did not interfere in the biofilm production in any of the thirty isolates tested, where 100% were biofilm formers, with 13.3% as strong adherents. The extract obtained relevant results in vitro, inhibiting the action of the biofilm in formation and consolidation, besides inhibiting the motility, producing migration zones smaller than the control samples, without extract. In the ex vivo model the extract showed no toxicity in the group exposed only to it. In the group where the samples were submitted to the action of BSE + Inoculum there was degrading action of the bacterium on the epithelium, but in a smaller amplitude when compared with Group B, only with the presence of the inoculum in the epithelium. The phytotherapic presented promising in the fight against factors such as biofilm and bacterial adherence that increases the microbial pathogenicity, besides not being toxic in the ex vivo model.