The objective of this work is to determine the phenotypic characterization of enterobacteria with a view to identifying them, extracting aromatic oils, and preparing ethereal, chloroformic extracts of foods, in order to test the antibacterial activity of four foods, among other Allium sativum, Allium schoenoprasum, Allium cepa and Allium porrum.The aqueous, ethereal and chloroform extracts were obtained by hydro-distillation and by the extraction method using ether and chloroform respectively.As a result, the strains observed are Gram negative bacteria; their morphological and biochemical characterization made it possible to identify three germs including Citrobacter sp, Proteus mirabilis and Escherichia coli.The study of the sensitivity of these strains to hydro-distillation, to the ethereal and chloroform extract of Allium sativum, Allium schoenoprasum, Allium cepa and Allium porum by the method of diffusion in agar medium led to the following results: strains S8, S13 and S16 inhibited on hydro distillation (8; 15; 16mm of inhibition diameters); the ethereal extract of these same drugs inhibited the S14 strains for garlic (with 8mm inhibition diameter; S13 and S16 for chives (with 10mm inhibition diameter) and finally, the S16 strain for onion (with 16mm inhibition diameter), on the other hand, the chloroformic extract presented the zones of inhibition to strains S15 and S16 (14 and 12mm inhibition diameter) for Allium sativum (garlic); to strains S6 and S16 (9 and 13mm inhibition diameters) for Allium schoenoprasum (chives) and finally, strain S16 (17mm inhibition diameter) for Allium cepa (onion).Further in-depth research should be encouraged in order to make available to society effective and less expensive products which fight against antibiotic-resistant enterobacteria in the Kisangani region.