M.Sc.

         This study aimed to determine the frequency of Salmonella Typhimurium and its multi-drug resistance (MDR) status as a diarrheal causative pathogen in children younger than five years old, as well as to investigate the role of four probiotic microorganisms(L.acidophillus,L.casei,S.cerevisiae,S.boulardi) in controlling such infection.For this purpose, 128 stool samples of patients (76 males and 52 females)

      Soil samples were collected from fields cultivated with wheat and barley and from spoiled orange, apple fruits and carrot roots to enzyme  isolate bacteria producing lytic. Bacterial isolates were screened for enzymes production on selective media containing carboxymethyl cellulose (CMC) or pectin as a sole source for carbon and energy.

Many experiments were carried out to investigate the ability of Ruta graveolens to tolerate heavy metals in vitro and to investigate molecular bases of heavy metals tolerance.