Synergistic effects of ethanolic plant extract mixtures against food-borne pathogen bacteria

Plant extracts are an important part in agroecology, as they benefit environment in combating pathogenic organisms, without resorting to synthetic chemicals. The objective of this study was to evaluate the antibacterial activity of mixtures of ethanol extracts from semi-desert plants [creosote bush (Larrea tridentata), tarbush (Flourensia cernua) and paddle cactus (Opuntia ficus-indica)] against Enterobacter aerogenes, Escherichia coli, Salmonella typhi and Staphylococcus aureus. The maximum antimicrobial activity was achieved with the creosote bush–tarbush-paddle cactus mix (1:1:1) v/v, followed by paddle cactus-tarbush (1:1) v/v. E. coli was the bacterial strain that showed the highest growth inhibition as consequence of the concentration of plant extracts (4000 and 5000 ppm of tarbush). While with the creosote bush plant extracts, the highest inhibition halos were observed. Synergistic effects were observed when mixtures of ethanolic plant extract against food-borne pathogen bacteria were used, so this may be a better way to design alternative pathogen control methodologies for food-borne pathogen bacteria.   Key words: Larrea tridentate, Flourensia cernua, Opuntia ficus-indica, ethanolic plant extract mixtures, food-borne pathogen.