Résumé:
The aim of this work is to study the susceptibility of four different strains and to select some
resistant isolates. The results revealed that the Enterobacter sp strain was sensitive to all
antibiotics tested, Staphylococus aureus and Bacillus cereus were resistant to retarciline and
Pseudomonas aeruginosa was sensitive to ampicillin and gentamycin and resistant to
cefazoline, Retarciline, Biopamox and Vibramycin .
The resistance rate of these strains to the antibiotics tested was 25% with cefazolin,
vebramycin and biopamox and 75% with retarcilin.
Then the Enterobacer sp strain was chosen to select resistance to cefazolin. 49 resistant
isolates of different size were obtained and the resistance mutation frequency was calculated
(3.06 10 -7). Then the antibiogramme of some representative resistant isolates revealed that
they are resistant to all antibiotics tested.
The resistance of the resistant isolates of these strains to the antibiotic tested was 100%.
