Hamames, Mokhtar2024-02-112024-02-112012http://dspace.univ-khenchela.dz:4000/handle/123456789/395n order to evaluate the phenomena of bacterial resistance to antibiotics in aquatic ecosystems, particularly in surface waters, it was interested to study Sebkhet Ouled M’barek of the City of Khenchela, a water plan exposed to microbial pollution of fecal origin. In our study, we have begun by estimating the microbiological quality of water using different research methods and enumeration of test germs of fecal contamination. The results showed a significant microbial pollution of our study area. Seven bacterial species were identified: Escherichia coli, Aeromonas hydrophila, Methylobacterium mesophilicum, Shewanella putrefaciens, Comamonas testosteroni, Staphylococcus epidermidis and Enterococcus faecium. The study of antibiotic resistance showed, for E.coli, acquired resistance to Ampicillin and Ticarcillin (by a low- level penicillinase) and to Chloramphenicol (by chloramphenicol acetyltransferase). A. Hydrophila and the three other non- fermenting bacilli have a wild-type resistance. S. epidermidis has acquired resistance to penicillin (by penicillinase plasmid), Oxacillin and Erytromycin (by efflux mechanism). E. faecium have a wild-type resistance. The study of the association of antibiotics on A. Hydrophila showed greater synergy between colistin and cefotaxim. The technique of the chessboard allowed us to reveal, to these two antibiotics, the lowest concentration giving a better effect on the growth of this species. They amount respectively 166.5 and 6.25 µg / ml.frThesis