Adenovirus and rotavirus recovery from a treated effluent through an optimized skimmed-milk flocculation method

Abstract

Sewage treatment may be insufficient for the complete removal of enteric viruses, such as human adenoviruses (HAdV) and group A rotavirus (RVA). The differences in the efficiency of the treatment methodologies used may interfere with the detection of these viruses. The objective of this study was to optimize a skimmed-milk flocculation technique for the recovery of HAdV and RVA in the samples of treated effluent. The treated effluent collected at the wastewater treatment plant (WWTP) was processed via four protocols including modifications in the initial centrifugation step and the final concentration of skimmed-milk. The viral load and recovery rate were determined by quantitative PCR TaqMan® System. The highest recovery rates of HAdV, RVA, and bacteriophage PP7 (internal control process) were obtained when the concentration of skimmed-milk was doubled and no centrifugation step was used for the sample clarification. The optimized protocol was assessed in a field study conducted with 24 treated effluent samples collected bi-monthly during 2015. HAdV and RVA were detected in 50.0% (12/24) and 33.3% (08/24) of the samples tested, respectively, throughout the year, without seasonal variation (p > 0.05). This study corroborates the use of the organic flocculation method for virus recovery in environmental samples with the adaptation of the protocols to different aquatic matrices.

Photobiomodulation mechanisms in the kinetics of the wound healing process in rats

Publication date: Available online 8 April 2018
Source:Journal of Photochemistry and Photobiology B: Biology
Author(s): A.N. Otterço, A.L. Andrade, P. Brassolatti, K.N.Z. Pinto, H.S.S. Araújo, N.A. Parizotto
ObjectivesThe healing process of cutaneous lesions is considered a complex event divided into distinct and overlapping phases, which responds satisfactorily to photobiomodulation (PBM). PBM is indicated as a therapeutic resource capable of assisting tissue repair. The present study aimed to analyze the kinetics of cutaneous wounds healing process after application of the GaAlAs laser for treating wounds on the dorsum of rats.Materials and MethodsThis study was approved by the Animal Ethics Committee of UFSCar. The animals were divided into 2 groups (n = 10); control group (CG) used 0.9% saline solution and the laser group (LG) used GaAlAs, 670 nm continuous pulse, 30 mW power, 14.28 J/cm² energy density, irradiating 1 point per wound for 30s, totaling 15 consecutive days of treatment. Samples were collected on the 4th, 11th and 16th days for histological analysis of HE, Picrosirius-Red, immunohistochemistry (Collagen1, TNF-α, VEGF). Statistical analyzes used the one-way ANOVA test for intra and inter group evaluations, and the Tukey post-test. Level of significance was set at p < 0.05.ResultsThe histopathological analysis (HE) showed a statistically significant difference for lower values of inflammatory infiltrate in LG versus CG on the 16th day; and for the increase of collagen in the 11th and 16th days of treatment. There was a statistically significant difference in the increase of VEGF on the 11th day for LG; decrease of TNF-α on the 4th and 11th day for LG, and increase of collagen type 1 on the 4th and 16th days for LG. The birefringence analysis of the percentage of collagen fibers presented on the 11th day of treatment revealed a greater quantity and significant statistical difference. Collagen fibers showed improved organization and arrangement on the 11th day for LG.ConclusionOur results show that PBM is effective in helping the kinetics of the cutaneous wound healing process in rats and promotes the necessary stimuli for the satisfactory evolution of healing process, ultimately leading to structurally desirable tissue.