[Preliminary study of the antimicrobial activity of traditional plants against E. coli]

The microbiological quality of drinking water is a major public health priority in developing countries. As an alternative proposal to chemical treatment of water, we have studied the antibacterial effectiveness against E. coli of plants traditionally used for antisepsis. Traditional plants were freshly sampled from Burkina Faso and Vietnam. Two of them, Tamarinier and Derris elliptica respectively, were selected for the study. Various part of the plants, i.e. seeds, cloves and fruits were prepared in both decoction and maceration. Their antibacterial activity was assessed using standardized preparations of E. coli (Pasteur 792) in water (10(5), 10(6) and 10(7) germs/ml). Some preparations of Tamarinier showed encouraging results, whereas Derris elliptica was uneffective. Solutions of Tamarinier seeds produced a 4.5 log decrease of the germ concentration in standardized 10(7) germs/ml preparation. Decoction and maceration are still effective 24 h after a 10(4) bacteria/ml overloading. On the other hand, acid pH of clove and fruit solutions explains the slight effectiveness (1 log UFC/g of dry extract/48 h) of these solutions. Though the results are not meeting with the AFNOR requirements for disinfection, this preliminary study demonstrates a bacteriostatic effect of traditional plants against E. coli in water. Further study is needed to valid this property in the field.