Mitigation of viruses of concern and bacteriophage surrogates via common unit processes for water reuse: A meta-analysis.

Water reuse is a growing global reality. In regulating water reuse, viruses have come to the fore as key pathogens due to high shedding rates, low infectious doses, and resilience to traditional wastewater treatments. To demonstrate the high log reductions required by emerging water reuse regulations, cost and practicality necessitate surrogates for viruses for use as challenge organisms in unit process evaluation and monitoring. Bacteriophage surrogates that are mitigated to the same or lesser extent than viruses of concern are routinely used for individual unit process testing. However, the behavior of these surrogates over a multi-barrier treatment train typical of water reuse has not been well-established. Toward this aim, we performed a meta-analysis of log reductions of common bacteriophage surrogates for five treatment processes typical of water reuse treatment trains: advanced oxidation processes, chlorination, membrane filtration, ozonation, and ultraviolet (UV) disinfection. Robust linear regression was applied to identify a range of doses consistent with a given log reduction of bacteriophages and viruses of concern for each treatment process. The results were used to determine relative conservatism of surrogates. We found that no one bacteriophage was a representative or conservative surrogate for viruses of concern across all multi-barrier treatments (encompassing multiple mechanisms of virus mitigation). Rather, a suite of bacteriophage surrogates provides both a representative range of inactivation and information about the effectiveness of individual processes within a treatment train. Based on the abundance of available data and diversity of virus treatability using these five key water reuse treatment processes, bacteriophages MS2, phiX174, and Qbeta were recommended as a core suite of surrogates for virus challenge testing.

The effects of vitamin E on colistin-induced nephrotoxicity in treatment of drug-resistant gram-negative bacterial infections: A randomized clinical trial.

INTRODUCTION: Nephrotoxicity remains a major long-standing concern for colistin, and it is critical to find agents that can prevent it. The present study aims to investigate the effect of vitamin E on the prevention of colistin-induced nephrotoxicity based on its antioxidant and free radical scavenging properties. METHODS: A randomized clinical trial was designed for 52 patients taking colistin. These patients were categorized into two groups of equal size, receiving colistin or colistin plus vitamin E (α-Tocopherol). Vitamin E with doses of 400 units was administrated daily either orally or by a nasogastric tube if needed. The incidence of Acute Kidney Injury (AKI) and its duration was recorded based on RIFLE criteria. RESULTS: The Incidence of AKI based on RIFLE criteria was 42.3% and 46.2% in intervention and control groups, respectively. The analysis showed no significant difference in the prevalence of AKI for the two groups (P = 0.78). There was no significant difference in the duration of AKI neither (P = 0.83). CONCLUSION: Although vitamin E is a powerful biological antioxidant, the effects of Vitamin E prophylaxis on colistin-induced nephrotoxicity was not taken into consideration in this study.