Resistance and induction of viable but non culturable states (VBNC) during inactivation of E. coli and Klebsiella pneumoniae by addition of H2O2 to natural well water under simulated solar irradiation

Inactivation of Escherichia coli and Klebsiella pneumoniae by addition of H2O2 10 mg L-1 into natural well water samples containing natural total iron concentrations (around 0.3 mg L-1) under simulated solar light was followed by bacterial culturability (plate count) and viability (DVC-FISH). Results showed that culturability of both bacteria was totally reduced while viability was only completely depleted for E. coli in well water samples depending of total iron concentration. Post-irradiation effects in presence of residual H2O2 showed that viability of both bacteria kept dropping being totally reduced for E. coli cells while K. pneumoniae decreased only 1-log. SEM micrographs showed that E. coli and K. pneumoniae cells underwent morphological changes and size reduction according to VBNC states. Different dark and photo-induced processes where physical-chemical features of groundwater samples play an important role could be responsible of bacteria abatement.Fil: Alvear Daza, John Jairo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: García Barco, Alejandra. Universidad Tecnológica de Pereira; ColombiaFil: Osorio Vargas, Paula Alejandra. Universidad Tecnológica de Pereira; Colombia. Universidad del Bio Bio; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gutierrez Zapata, Hector Mario. Universidad del Valle; ColombiaFil: Sanabria, Janeth. Universidad del Valle; ColombiaFil: Rengifo Herrera, Julian Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentin

Ciprofibrate therapy in patients with hypertriglyceridemia and low high density lipoprotein (HDL)-cholesterol: greater reduction of non-HDL cholesterol in subjects with excess body weight (The CIPROAMLAT study)

BACKGROUND: Hypertriglyceridemia in combination with low HDL cholesterol levels is a risk factor for cardiovascular disease. Our objective was to evaluate the efficacy of ciprofibrate for the treatment of this form of dyslipidemia and to identify factors associated with better treatment response. METHODS: Multicenter, international, open-label study. Four hundred and thirty seven patients were included. The plasma lipid levels at inclusion were fasting triglyceride concentrations between 1.6–3.9 mM/l and HDL cholesterol ≤ 1.05 mM/l for women and ≤ 0.9 mM/l for men. The LDL cholesterol was below 4.2 mM/l. All patients received ciprofibrate 100 mg/d. Efficacy and safety parameters were assessed at baseline and at the end of the treatment. The primary efficacy parameter of the study was percentage change in triglycerides from baseline. RESULTS: After 4 months, plasma triglyceride concentrations were decreased by 44% (p < 0.001). HDL cholesterol concentrations were increased by 10% (p < 0.001). Non-HDL cholesterol was decreased by 19%. A greater HDL cholesterol response was observed in lean patients (body mass index < 25 kg/m(2)) compared to the rest of the population (8.2 vs 19.7%, p < 0.001). In contrast, cases with excess body weight had a larger decrease in non-HDL cholesterol levels (-20.8 vs -10.8%, p < 0.001). There were no significant complications resulting from treatment with ciprofibrate. CONCLUSIONS: Ciprofibrate is efficacious for the correction of hypertriglyceridemia / low HDL cholesterol. A greater decrease in non-HDL cholesterol was found among cases with excess body weight. The mechanism of action of ciprofibrate may be influenced by the pathophysiology of the disorder being treated

Addition of hydrogen peroxide enhances abiotic sunlight-induced processes to simultaneous emerging pollutants and bacteria abatement in simulated groundwater using CPC solar reactors

Results revealed that almost 90% of 2,4-D (70 μg L−1), present in simulated groundwater containing 0.3 mg L−1 of iron at pH 7.0, was degraded after 320 min (60 min t30w) of natural sunlight irradiation while the viability of Escherichia coli cells (followed by DVC-FISH) was completely reduced after 220 min (40 min t30w) by simple addition of 10 mg L−1 of hydrogen peroxide. Klebsiella pneumoniae exhibited an especial behavior since its viability was only reduced in 3.5 logs after 320 min of sunlight irradiation (60 min t30w). Dark experiment (in presence 10 mg L−1 of H2O2) showed that Fenton processes may also play an important role reducing the 40% of 2,4-D after 320 min (60 min t30w) while viability of E. coli and K. pneumoniae underwent a reduction of 2.5 and 2 logs respectively. Photolysis experiments were not able to degrade 2,4-D and E. coli and K. pneumoniae viability was partially reduced (2 logs). Results showed that high 2,4-D abatement could be due to photo-induced and/or dark processes such as photo-Fenton and Fenton (dissolved and colloidal iron), photocatalysis (colloidal iron) and UV-B photolysis of H2O2. Viability reduction of microorganisms should be related to combined effects of UV-A + B irradiation, rising of temperature (44 °C), photo-Fenton, Fenton and photocatalytic processes.Fil: Gutiérrez Zapata, Hector Mario. Universidad del Valle. Fundación Samanea; ColombiaFil: Sanabria, Janeth. Universidad del Valle. Fundación Samanea; ColombiaFil: Rengifo Herrera, Julian Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas ; Argentin