Escherichia coli strain Nissle 1917(Ardeypharm)

This study was conducted to evaluate the effects of E.coli Nissle 1917 (EcN) on immune responses, blood parameters, oxidative stress, egg quality, and performance of laying Japanese quail. A total of one-hundred day-old quail chicks were assigned to 1 of 4 treatments based on probiotic concentration: 1 (0 CFU/mL; control), 2 (10⁴ CFU/mL), 3 (10⁶ CFU/mL), and 4 (10⁸ CFU/mL). The average egg production throughout the 8 wks of the laying phase increased with the increase in EcN supplementation (R²= 0.96). The egg production was also significantly different in wk 4, 7, and 8 of the laying phase with the control group demonstrating the poorest performance. External egg quality parameters, including shell strength, Roche index, albumen height, yolk weight, shell weight, shell thickness, and Haugh unit, also showed higher values in groups receiving EcN. Likewise, these groups demonstrated heavier egg weight (EW) and lower MDA in the meat sample. The MDA concentration of fresh yolk samples in groups receiving EcN was higher but diminished after iron-inducing (P < 0.05). No differences were observed in ADFI, FCR, EM, yolk cholesterol and triglyceride, hematocrit, SRBC, NDV, CMI immune responses (DNCB and PHA), H:L ratio, and internal organ weights. Plasma cholesterol and uric acid were the only blood constituents showing higher values in male birds in groups of EcN (P < 0.05); no appreciable differences were observed in the rest of the blood parameters in male birds and none in females. Further, a substantially higher Avian Influenza Virus (AIV) titer resulted from treatments 3 and 4 in male birds among humoral immune responses. These results demonstrated that EcN in the birds' drinking water could profoundly influence laying performance, egg quality, immune function, and enhanced antioxidant capacity.

Engineered bacteria offer a novel approach to targeted cancer therapy, but challenges remain in delivering enough bacteria safely for effective treatment. Previous efforts have used either a native or synthetic coating to achieve better control over the half-life of bacteria in the body but have limitations in delivery or versatility. In this work, we optimized and evaluated a synthetic coating for probiotic Escherichia coli Nissle 1917 to increase its half-life in blood and thereby increase the bioavailability of intravenous doses of bacteria to colonize and treat tumors. Using a simple one-pot chemical process, we coated bacteria with iron and tannic acid (FeTA) to form a temporary adhesive protective coating surrounding the bacterial cell surface. The iron to tannic acid ratio of the coating was optimized for intravenous use, and FeTA-coated bacteria of several different genetic backgrounds showed 15-fold higher survival in blood survival assays for up to 4 hours. We found that the FeTA coating reduced both complement-mediated bacterial killing and phagocyte-mediated bacterial killing in vitro. As a result, systemic delivery of attenuated bacteria had up to 60% colonization efficiency of FeTA-coated bacteria in an orthotopic breast cancer mouse model compared to 10% for the non-coated control, all the while maintaining a two-fold decrease in weight loss of attenuated bacteria compared to wild-type. Altogether, we show that an optimized FeTA coating significantly extends the half-life and colonization efficiency of engineered bacteria, overcoming a key limitation of their application in cancer therapy.