Atividade antimicrobiana de óleos essenciais em bactérias patogênicas de origem alimentar

Abstract

The objective of this work was to identify and quantify the constituents, and to evaluate the antimicrobial activity of the essential oils from Mentha piperita, Cymbopogon citratus, Ocimum basilicum and Origanum majorana, against enteropathogenic Escherichia coli, Salmonella enterica Enteritidis, Listeria monocytogenes and Enterobacter sakazakii. The essential oils were obtained from dried leaves by using the hydrodistillation technique and the modified Clevenger apparatus, and their bacterial activity was determined by using the agar diffusion technique. The essential oils inhibited bacterial growth, but their effectiveness was varied. Among the essential oils tested, that from M. piperita showed a greater antimicrobial activity against E. coli (8.106 UA mL -1 ), moderate activity for S. enterica Enteritidis and E. sakazakii (1.706 e 3.200 UA mL -1 respectively) and low activity for L. monocytogenes (106,67 UA mL -1 ). However, the essential oil from C. citratus presented a greater antimicrobial activity against E. coli (9.386 UA mL -1 ) and a moderate activity against E. sakazakii, S. enterica Enteritidis and L. monocytogenes (2.773 UA mL -1 for both). The essential oil from O. basilicum showed a greater antimicrobial activity against E. coli and E. sakazakii (6.826 e 8.106 UA mL -1 respectively), moderate activity against S. enterica Enteritidis (1.600 UA mL -1 ), and was inactive against L, monocytogenes. Origanum majorana, which was also tested in our work, showed a greater antibacterial activity against E. coli, (5.973 UA mL -1 ) moderate activity against S. enterica Enteritidis and E. sakazakii (1.706 e 2.346 UA mL -1 , respectively), and was inactive against L. monocytogenes.