MOLECULAR IDENTIFICATION OF WHITE CHEESE BACTERIAL ISOLATES AND ANTIBACTERIAL ACTIVITY OF Tamarix nilotica PLANT EXTRACT

Foodborne illnesses linked to consumption of cheese with several bacteria have been reported. In this study eight samples of white cheese collected from each two big markets in Jeddah City were analyzed microbiologically at different time at 2018. One gram of cheese sample from the upper surface was taken to prepare serial dilution and100 µl of each dilution were spread on top of the nutrient agar (NA) medium then incubated at 37°C. Bacterial colonies were picked up and seven bacterial colonies were selected to be identified using the 16S rRNA sequencing. The sequences were submitted to the NCBI Gene Bank (www.ncbi.nlm.nih.gov) under accession numbers: Mw148338 for B. cereus (S1); Mw148339 for Staphylococcus aureus (S2); Mw148340 for Bacillus paramycoides (S3)); Mw148341 for Staphylococcus aureus (S5); Mw148342 for Serratia proteamaculan (S6); Mw148343 for Serratia proteamaculan (S7) and Mw148344 for Serratia proteamaculan (S9). Tamarix nilotica medical plant extracts collected from Al-Laith Village-Makkah Region-Kingdom of Saudi Arabia evaluated against these isolates of bacteria. The ethanol (Extract cc1) and ethyl acetate (Extract cc2) extracts of Tamarix nilotica were tested in vitro against these bacterial strains using the agar well diffusion technique. Antibacterial activity was evaluated by measuring the zone of inhibition formed around wells using different concentrations (10, 20, 25 and 30 µl) as 0.1137 mg (30 µl) of Extract cc1and 0.51 mg (30 µl) mg/ml for Extract cc2 per well), then incubated at 37◦C for 24 hrs. Results indicated that the ethanolic and ethyl acetate extracts of Tamarix nilotica plant showed antibacterial activity against all strains using (0.1137 mg) of Extract cc1and (0.51 mg) of Extract cc2 (30 µl) but Extract cc2 was more effective when compared to the Extract cc1. Further study to determine the chemical constituents of Tamarix nilotica plant will be useful for the development antibacterial agent.