RESUMO
AIMS OF THE STUDY: The ability of Yersinia enterocolitica strains to form biofilms and the capacity of different alkaloids to inhibit biofilm formation were investigated. METHODS AND RESULTS: The capacity to form biofilm on polystyrene of 31 Y. enterocolitica strains was evaluated. Biofilm and quorum sensing (QS) inhibition of 17 alkaloids were assayed; furthermore, minimum biofilm inhibitory concentration (MBIC) was determined. The capacity to form biofilms among the examined strains seemed to be a strain-related feature. The best biofilm inhibitors at 100 µmol l-1 were oliverine (1), guatterine (3), liriodenine (4), oliveridine (5) and pachypodanthine (6), which showed biofilm inhibition higher than 87%. Pachypodanthine (6) was the most effective compound with MBIC value of 12·5 µmol l-1 at subinhibitory concentration and also was able to inhibit QS system and reduce yenR expression at this concentration. CONCLUSION: This is the first study to demonstrate that oliverine, liriodenine, and pachypodanthine are able to inhibit biofilm formation of Y. enterocolitica without critically disturbing its growing capacity. At MBIC, pachypodanthine inhibited biofilm formation and QS. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of aporphinoid alkaloids as biofilms inhibitory agents might potentially be useful to treat biofilm-associated infections in the future.
Assuntos
Alcaloides/farmacologia , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Produtos da Carne/microbiologia , Yersinia enterocolitica/efeitos dos fármacos , Alcaloides/química , Antibacterianos/química , Biofilmes/crescimento & desenvolvimento , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Percepção de Quorum/efeitos dos fármacos , Fatores de Virulência/genética , Yersinia enterocolitica/isolamento & purificação , Yersinia enterocolitica/fisiologiaRESUMO
Foodborne diseases have become a health issue worldwide, mainly due to the consumption of contaminated foods that are either raw, improperly heat treated or cross-contaminated after adequate heat treatment foods. A group of alkaloids extracted from plants were tested to evaluate their antimicrobial effect against different strains of Yersinia enterocolitica and other foodborne bacteria. The results obtained reveal that oliveridine and pachypodanthine inhibited Y. enterocolitica growth, with MIC values of 25 µmol l-1 and 100 µmol l-1 respectively. The results indicated that both alkaloids are good growth inhibitors, but oliveridine showed greater inhibitory effect with lower MIC values. Inhibitory alkaloids can be developed as potential antimicrobials in food system to prevent or treat foodborne diseases, thus contributing to solve the global issue of contaminated food consumption. SIGNIFICANCE AND IMPACT OF THE STUDY: Alkaloids are abundant secondary metabolites in plants and represent one of the most widespread class of compounds endowed with multiple and varied pharmacological properties. In this work, we propose two aporphinoid alkaloids extracted from plants as new antimicrobial agents. Oliveridine and pachypodanthine inhibited Yersinia enterocolitica growth for up to 96 h of culture. This is the first reported study of the activity of these alkaloids as antimicrobial compounds.