Antibacterial activity of essential oils against bacteria isolated from the mussel Mytella falcata

Abstract

The growing increase of bacteria resistance to commercially-traded antimicrobials has encouraged the search for new,  more powerful pharmics against their action, because since immemorial time the plants’ therapeutic properties have been ackno - wledged. In this paper the antibacterial activity of five essential oils, namely guava tree,  Psidium guajava L.; basil,  Ocimum  gratissimum L.; ginger,  Zingiber officinale Roscoe; rosewood,  Aniba duckei Kostermans; and allspice,  Pimenta dioica Lin - dl, in isolated samples of  Escherichia coli, Salmonella spp,  Vibrio parahaemolyticus and Staphylococcus positive coagulase  isolated from the mussel  Mytella falcate , found in four estuaries and fishmarkets of São Luís, Maranhão State, Brazil. Two  different methods were used: disc diffusion (MDD) and radial diffusion in two layers of drilled agar (MDRCAP), compared  with twelve commercial antimicrobials, through the sensitivity measured according to the Kirby-Bauer method. The antimicro - bial action by the essential oils showed a statistically-significant difference between methods, being the rosewood-derived one the  most powerful. Their antibacterial activity underscores the importance of those plants as a low-cost natural alternative for food  conservation and therapeutic practices.