Antibacterial effect of ethanolic extracts of Moroccan plant against Escherichia coli

Rural populations of morocco are still taking their water supplies from unprotected sources such as wells and springs that are usually contaminated. in order to protect citizens against diseases,water treatment is crucial. moreover,the use of chlorine as disinfectant may produce toxic compounds (trihalomethanes) that have health risks. it is therefore necessary to find alternative methods of water disinfection. our investigation was focused on the evaluation of efficiency of seven moroccan plant extracts against a fecal bacterium: escherichia coli (gram negative) found in the prospected springs. the in vitro antibacterial studies were carried out using ethanolic extracts of pomegranate (punica granatum l.) and bitter orange (citrus x aurantium l.) seed as well as fig (ficus carica l.),oregano (origanum elongatum (bonnet) emb. & maire),lemon balm (melissa officinalis l.),thyme (thymbra capitata (l.) cav.) and myrtle (myrtus communis l.) leaves. the results showed that the ethanolic extract of origanum elongatum leaves was the most effective against escherichia coli with 30.33±2.51 mm of diameter of inhibition zone. besides,the ethanolic extracts of myrtus communis,thymbra capitata leaves and punica granatum seeds had also a significant antibacterial activity against escherichia coli with diameters of inhibition of 20.16±0.76,11.33±1.15 and 17.33±4.50 mm respectively. on the other hand,preliminary phytochemical screening showed that the most active extracts contains a significant quantity of phenols. phenolic contents for these extracts ranged between 100.69±3.40 and 136.83±1.03 (mg gae / g of extract). © 2017,university of mohammed premier oujda morocco