The sharp increase in antibiotic resistance imposes a global threat to human health and the discovery of effective antimicrobial alternatives is needed. The use of probiotics to combat bacterial pathogens has gained a rising interest. Pathogenic is causative of multiple clinical syndromes such as diarrheal diseases, meningitis and urinary tract infections. In this work, we evaluated the efficacy of probiotics to control multidrug-resistant and reduce their ability to form biofilms. Six resistant to at least five antibiotics (Ceftazidime, Ampicillin, Clarithromycin, Amoxicillin + Clavulanic Acid and Ceftriaxone) were isolated in this work. Preparations of cell-free spent media (CFSM) of six probiotics belonging to the genus and which were grown in Man-Rogosa-Sharpe (MRS) broth exhibited strong antibacterial activity (inhibition zones of 11.77-23.10 mm) against all isolates. Two isolates, namely WW1 and IC2, which were most resistant to all antibiotics were subjected to antibiofilm experiments. Interestingly, the CFSM of MRS fermented by all probiotics resulted in inhibition of biofilm formation while caused highest inhibition (57.94%) in case of IC2 biofilms and was responsible for 64.57% reduction of WW1 biofilms. On the other hand, CFSM of skim milk fermented by and exhibited a slight inhibitory activity against IC2 isolate (inhibition percentage of 31.52 and 17. 68, respectively) while WW1 isolate biofilms was reduced by CFSM of milk fermented by and (70.81 and 69.49 reduction percentage, respectively). These results support the effective use of probiotics as antimicrobial alternatives and to eradicate biofilms formed by multidrug-resistant .

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In the microbial electrochemical system (MES), the microbial-electrode interactions are often regulated by the metabolic pathway and respiratory activities. To improve the efficiency of MES, there is a need to introduce a microbial community that provides a continuous oxidation of organic substrates with a sustainable current output. Thus, activated sludge was suggested and the rapid evaluation of its biodegradation activity, using cyclic voltammetry, was performed. Stimulation of the metabolic pathway led to the appearance of an oxidation peak current (22 μA/cm(2), at about 750 mV), whereas the electrochemical signals were originated only from the metabolically active microbes. Cell viability, cultivation time, type, and concentration of the degradable organic substrates have been identified as major regulators for the electrocatalytic performance. From two different microbial communities, the generated electrochemical signal of the aerobic activated sludge was more than twofold higher in converting the degradable organic substrates (glucose, acetate, and succinate at 10 g/L) into oxidation current. On the other hand, the secretion of electroactive metabolite(s) in the extracellular matrix was determined as a source of electrochemical signal. Moreover, the mechanism(s) of the microbe-electrode interactions were demonstrated. Therefore, the current bioelectrochemical system could be used as a platform for monitoring the rate of substrate degradation as well as measuring the metabolic pathway activity.

Omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have beneficial effects on human health. The probiotic bacterium Escherichia coli Nissle is unable to produce either EPA or DHA. Escherichia coli Nissle was transformed with the pfBS-PS plasmid carrying the EPA/DHA gene cluster, previously isolated from a marine bacterium. The transgenic E. coli Nissle produced EPA when grown at 10ºC (16.52 ± 1.4 mg g(-1) cell dry weight), 15ºC (31.36 ± 0.25 mg g(-1) cell dry weight), 20ºC (13.71 ± 2.8 mg g(-1) cell dry weight), 25ºC (11.33 ± 0.44 mg g(-1) cell dry weight) or 30ºC (0.668 ± 0.073 mg g(-1) cell dry weight). Although DHA was also produced at all these temperatures, it comprised less than 0.2% of total extracted fatty acids. Transcriptomic analysis using Reverse Transcription qPCR showed upregulation of the entire gene cluster in E. coli Nissle. Among EPA/DHA genes, pfaB, pfaC and pfaD were overexpressed (expression ratio of 181.9, 39.86 and 131.61, respectively) as compared to pfaA (expression ratio of 3.40) and pfaE (expression ratio of 4.05). The EPA/DHA-producing probiotic E. coli Nissle may be used as a safe, alternative and economic source for the industrial and pharmaceutical production of EPA and DHA.

Introduction. Pomegranate is an old fruit which has many antimicrobial compounds. Impact of pomegranate peel extracts on Escherichia coli clinical isolate from Benha general hospital was investigated in this study. Material and Methods: pomegranate peel extraction was primed and GC/MS chromatogram analysis was carried out using the GC Agilent Technologies gas chromatography fitted with HP-5 fused silica column (25mm × 0.25mm, film thickness of 0.25 µm) and interfaced to the flame-ionization detector (FID). The antibacterial potential of Pomegranate peel extractions against E.coli sample was done using well diffusion method. Results: According to (GC/MS) technique, methanol and aqueous extracts of pomegranate peel have inhibitory effects on E. coli isolate. The minimum inhibition concentrations (MICs) of methanolic and aqueous extracts were 100 and 60 mg/L, respectively. In this study , the MICs values of Aqueous extract of pomegranate peel were higher than of methanolic extract of pomegranate peel (P<0.05). Zones of inhibition and values of MICs indicated that the aqueous extract of pomegranate peel had more effect on E. coli isolate than methanolic extract of pomegranate peel. Conclusion: In this study, the extraction of pomegranate peel has antibacterial effect on E.coli isolate. However, the aqueous extract had a higher effect on E.coli than the methanolic extract.