A preliminary study on susceptibility of Escherichia coli strain nissle 1917 to transition metal stress

The susceptibility of probiotic strain to transition metals was examined by using Microdiluation Method for determination of minimum inhibitory concentration (MIC). E. coli Nissle 1917 has evolved into one of the best characterized probiotics, and its therapeutic efficacy and safety have convincingly been proven. The EcN was studied for its tolerance to two transition metals i.e. Cobalt (Co⁺²) and Copper (Cu⁺²) cultured at 37°C for 10 hr in Luria Bertani broth without shaking. Bacterial growth was measured every one hour using spectrophotometer. The susceptibility of EcN was compared with that of cell grown in the absence of transition metals free broths i.e. control. We observed dramatic alternation in the growth profiles pattern found stress exposed EcN to transition metals. All together our results strongly suggest that transition metals are toxic at higher concentration may be able to interact in their metabolism of Probiotic EcN strain.