Evaluation of Viral Recovery Methodologies from Solid Waste Landfill Leachate

Food and Environmental Virology - Leachate from solid waste landfill is a dark liquid of variable composition and possible source of contamination of groundwater and surface waters. This study aims...     

Viruses Surveillance Under Different Season Scenarios of the Negro River Basin,Amazonia, Brazil

The Negro River is located in the Amazon basin, the largest hydrological catchment in the world. Its water is used for drinking, domestic activities, recreation and transportation and water quality is significantly affected by anthropogenic impacts. The goals of this study were to determine the presence and concentrations of the main viral etiological agents of acute gastroenteritis, such as group A rotavirus (RVA) and genogroup II norovirus (NoV GII), and to assess the use of human adenovirus (HAdV) and JC polyomavirus (JCPyV) as viral indicators of human faecal contamination in the aquatic environment of Manaus under different hydrological scenarios. Water samples were collected along Negro River and in small streams known as igarapés. Viruses were concentrated by an organic flocculation method and detected by quantitative PCR. From 272 samples analysed, HAdV was detected in 91.9 %, followed by JCPyV (69.5 %), RVA (23.9 %) and NoV GII (7.4 %). Viral concentrations ranged from 10² to 10⁶ GC L^?1 and viruses were more likely to be detected during the flood season, with the exception of NoV GII, which was detected only during the dry season. Statistically significant differences on virus concentrations between dry and flood seasons were observed only for RVA. The HAdV data provides a useful complement to faecal indicator bacteria in the monitoring of aquatic environments. Overall results demonstrated that the hydrological cycle of the Negro River in the Amazon Basin affects the dynamics of viruses in aquatic environments and, consequently, the exposure of citizens to these waterborne pathogens.     

Detection and Molecular Characterization of Gemycircularvirus from Environmental Samples in Brazil

Gemycircularvirus (GemyCV) is a group of viruses which has been recently proposed as a new viral genus detected in fecal and environmental samples around the world. GemyCVs have been detected in human blood, brain tissue, cerebrospinal fluid, and stool sample. In the present study, we demonstrate for the first time, through molecular detection and characterization, the presence of GemyCVs in environmental samples from Brazil. Our results show a percentage of positivity ranging from 69 (25/36) to 97 % (35/36) in river water samples collected in Manaus, Amazon region, and wastewater from a wastewater treatment plant located in Rio de Janeiro, respectively, revealing GemyCVs as an important environmental contaminant.     

Measuring Suspended‐Sediment Concentration and Turbidity in the Middle Mississippi and Lower Missouri Rivers Using Landsat Data

The Middle Mississippi River (MMR) and lower Missouri River (MOR) provide critical navigation waterways, ecological habitat, and flood conveyance. They are also directly linked to processes affecting geomorphic and ecological conditions in the lower MR and Delta. For this study, a method was developed to measure suspended‐sediment concentration (SSC) and turbidity along the MMR and the lower MOR using Landsat imagery. Data from nine United States Geological Survey water‐quality monitoring stations were used to create a model‐development dataset and a model‐validation dataset. Concurrent gaging data were identified for available Landsat images to generate the datasets. Surface‐reflectance filters were developed to eliminate images with cirrus cloud coverage or vessel traffic. Using the filtered model‐development dataset, unique reflectance‐SSC and reflectance‐turbidity models were developed for three Landsat sensors: Landsat 8 Operational Land Imager, Landsat 7 Enhanced Thematic Mapper Plus, and Landsat 4–5 Thematic Mapper. Coefficient of determination values for the models ranged from 0.72 to 0.88 for the model‐development dataset. The model‐validation dataset was used to evaluate the performance of the models and had coefficient of determination values ranging from 0.62 to 0.79.     

Molecular Detection of Adenoviruses in Lakes and Rivers of Goiânia,Goiás,Brazil

Adenoviruses are a highly important public health issue, since they are among the most persistent and ubiquitous viruses present in water and associated with a variety of clinical manifestations. The aim of this study was to use molecular techniques for the detection of adenovirus in public and recreational water supplies in Goiania, Brazil. From December 2007 to November 2008, 54 water samples were collected in 5 different sites in 2 lakes and 2 rivers of the city. The samples were filtered in a positively charged nylon membrane, and the DNA was extracted using the phenol–chloroform–isoamyl alcohol method. Semi-nested PCR was used to detect adenovirus DNA, and sequence analysis of the semi-nested PCR products was performed to identify the recovered viruses. Adenovirus DNA was detected in 43% (24 of 54) of samples collected. Considering all examined sites, MP1 presented the highest occurrence of adenovirus (6 positive from 10 collected samples), followed by MP2 (3 positive from 6 collected samples), JL (10 positive from 21 collected samples), VB (3 positive from 9 collected samples), and BB (2 positive from 8 collected samples), respectively. The methodology employed proved to be feasible, fast, low-cost, and suitable to be used as screening approach on adenovirus detection in water for public sanitation companies.     

Chronic mixture toxicity study of Clophen A60 and diethyl phthalate in male rats

Chemical mixtures are an important area of research as individuals are exposed to low doses of persistent chemical agents known as environmental pollutants throughout their life time. Polychlorinated biphenyls (PCBs) and diethyl phthalate (DEP) are ubiquitous environmental pollutants that could be present in the same environmental compartment; hence organisms may get simultaneously exposed to both. Therefore, a study was undertaken to see whether PCB and DEP together show interactive chronic mixture toxicity in male Wistar rats. Healthy male Wistar rats weighing 70–100?g were randomly assigned to four groups of six each. Control rats were fed on normal diet and water ad libitum. Oil control rats were maintained on a normal diet mixed with corn oil. Rats were given Clophen A60 (PCB) and DEP dissolved individually in corn oil mixed with the diet at 50?mg?kg^?1 of the diet/day, as well as a mixture in corn oil mixed with the diet both at 50?mg?kg^?1 of the diet/day. After 150 days of treatment animals were sacrificed and enzymes and other biochemical parameters in the serum and liver were assessed. Liver weight to body weight ratio showed a significant increase in Clophen A60 and in Clophen A60?+?DEP treated rats. In the DEP, Clophen A60 and Clophen A60?+?DEP treated groups there was significant increase in liver and serum alanine aminotransferase (ALT) and acid phosphatase (ACP) activity. Aspartate aminotransferase (AST) was significantly increased in the liver and serum of DEP treated rats only. Cholesterol levels were significantly increased only in the serum and the liver of DEP treated rats. Triglyceride levels were significantly increased in the serum of treated rats and only in the liver of Clophen A60 and Clophen A60?+?DEP treated rats. Liver glycogen levels were significantly increased in DEP and Clophen A60?+?DEP treated rats. In all treated animals, there was a significant decrease in liver glutathione reductase (GR). Histology of liver showed severe vacuolations, fatty degeneration and loss of hepatic architecture in Clophen A60 and Clophen A60?+?DEP treated rats, whereas in DEP treated rats only loss of hepatic architecture and granular deposits in the hepatocytes was predominant with mild vacuolations of centrilobular and periportal area. It is evident from this study of mixture toxicity of Clophen A60 and DEP that there is no significantly enhanced toxicity due to the interaction of these two compounds. On the other hand, to some extent there is alleviation in toxicity as evidenced by enzyme ACP and AST levels in the liver. The hepatocellular damage and biliary congestion caused by these two compounds, which can be confirmed by significantly increased liver weights and elevated serum and liver enzyme levels as well as histology, was almost the same between individual and mixture treated group.     

Bacterial Degradation of Vegetable Oils

Following initial experiments presented elsewhere (2IOPS), the bacterial degradation of two vegetable oils was investigated in some detail. the number of aerobic and anaerobic heterotrophic bacteria, oil degrading and sulphate reducing bacteria were quantified during simulated spills on a salt marsh. the sediment fatty acid composition was also studied using GC-MS analysis. Degradation of linseed and sunflower oils was concomitant with an increase in the numbers of aerobic and anaerobic bacteria. Fatty acids analysis revealed preferential degradation of the principal components of the oils (18:3ω3 for linseed oil and 18:2ω6 for sunflower oil). the presence of several isomers of the usual polyunsaturated fatty acids was also detected. the identification of some of these new fatty acids has been carried out. Possible pathways of degradation of these vegetable oils are suggested.     

Breakwater control system and structural analysis: physical and numerical modelling (Port of Funchal,Madeira Island,Portugal)

The objective of this work was to analyze the behavior of the Funchal Port (Madeira Island, Portugal) breakwater using physical and numerical models in order to analyze the evolution of the underwater layers, combining information between the two models as well as simulating storm conditions and atypical docking/undocking impacts of cruise ships. Regarding the physical model using a wave generation system, the data collected and the test conditions were addressed considering different scenarios (return periods of 20, 50 and 100 years). It was found that for return periods of 20 years, the behavior of the infrastructure as a whole was stable. For return periods of 50 years, wave overtopping became more frequent and intense, and began to impact the superstructure. For the 100-year return period the behavior of the infrastructure was found to be unstable, with persistent wave overtopping. The morphology of the submerged layers also changed. The main objectives of the numerical model approach were to estimate the natural frequencies of vibration (when materials suffer a considerable modification, a change in their frequencies of vibration can be detected), and to calculate the expected displacements corresponding to cruise ship docking processes (agitation in a protected area) and the associated maximum maritime (agitation in an exposed area) forces. The maximum displacements obtained for the two cases were about 0.03 m, which is a high value. Considering the results obtained from this work, the Port authorities decided to maintain the monitoring program and perform an underwater video inspection.     

Stressed, but not defenceless: no obvious influence of irradiation levels on antifeeding and antifouling defences of tropical macroalgae

The production of defence metabolites is assumed to be costly in metabolic terms. If this holds true, low-light stress should reduce the ability of seaweeds to defend themselves chemically against herbivory and fouling. We investigated the effect of energy limitation on the defensive status of seaweeds by assessing their attractiveness to mesograzers and their activity against a bivalve macrofouler in comparison with non-stressed conspecifics. The macroalgae Codium decorticatum (Woodw.) M. Howe, Osmundaria obtusiloba (C. Agardh) R. E. Norris, Pterocladiella capillacea (S. G. Gmel.) Santel. and Hommer., Sargassum vulgare C. Agardh and Stypopodium zonale (Lamour.) Papenf. collected at the southeastern Brazilian coast were exposed to six levels of irradiation (between 1 and 180 μmol photons m⁻² s⁻¹) for 10–14 days. After this period, algae from all treatment levels were: (a) processed as artificial food and offered to an amphipod community dominated by Elasmopus brasiliensis Dana and (b) extracted to test for differences in settlement rates of the fouling mussel Perna perna L. on filter paper loaded with the crude extracts. Generally, photosynthesis rates and growth were reduced under low light conditions. Attractiveness to herbivores and macrofoulers, however, was insensitive to energy limitation. We discuss possible explanations for the observed absence of a relationship between light availability and algal defence including the change in nutritional value of the algal tissue, the allocation of resources towards defence instead of growth and the absence of costs for defence.