Evaluating seasonal dynamics of bacterial communities in marine fish aquaculture: a preliminary study before applying phage therapy

The increasing problem of antibiotic resistance in common pathogenic bacteria and the concern about the spreading of antibiotics in the environment bring the need to find new methods to control fish pathogens. Phage therapy represents a potential alternative to antibiotics, but its use in aquaculture requires a detailed understanding of bacterial communities, namely of fish pathogenic bacteria. Therefore, in this study the seasonal dynamics of the overall bacterial communities, microbiological water quality and disease-causing bacteria were followed in a marine aquaculture system of Ria de Aveiro (Portugal). Analysis of the bacterial diversity of the water samples by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments indicates that the bacterial community structure varied seasonally, showing a higher complexity during the warm season. The diversity of the main fish pathogenic bacteria, assessed by DGGE targeting the Vibrio genus, showed lower seasonal variation, with new dominating populations appearing mainly in the spring. Bacterial indicators, faecal coliforms and enterococci, enumerated by the filter-membrane method, also varied seasonally. The fluorescent in situ hybridization (FISH) results showed that the specific groups of bacteria varied during the study period and that the non-indigenous Enterobactereaceae family was the most abundant group followed by Vibrio and Aeromonas. The seasonal variation detected in terms of density and structure of total and pathogenic bacterial communities demonstrates the need for a careful monitoring of water through the year in order to select the suitable phages to inactivate fish pathogenic bacteria. The spring season seems to be the critical time period when phage therapy should be applied.     

‘Management Standards’ and work-related stress in Great Britain: Progress on their implementation

The aim of this paper is to identify what constituted barriers to progress in the implementation of the Management Standards for preventing and reducing work-related stress nationally, an approach advocated by the Health and Safety Executive in Great Britain. Data were collected from more than 100 public sector organisations through inspector visits and research interviews. Findings show that under supportive contexts, organisations were able to follow the process of a stepwise method for assessing psychosocial risks and implementing interventions using HSE assessment tools and guidance. Main enabling factors included the active and visible support from senior management, human resource departments, and line managers; regular communications on progress, sufficient organisational capability in terms of resources and expertise; departmental/team level assessment as opposed to an overall corporate wide assessment, and involvement of key stakeholders (e.g. Trade Union, employees). Some of the critical barriers across many public sector organisations included in this study were: major or on-going organisational changes; lack of organisational capability; and the resource intensive aspect of the method requiring focus groups in addition to stress survey data. Implications of the findings for policy development are discussed.     

Fractionation of rare earth and other trace elements in crabs, Ucides cordatus, from a subtropical mangrove affected by fertilizer industry

Fractionation of rare earth elements (REE) and other trace metal concentrations (Th, U, Cd, Cr, Cu, Ni, Pb, and Zn) between mangrove sediments and claw muscles and shells of male crabs (Ucides cordatus) from a subtropical estuary highly impacted by fertilizer industry activities was investigated. This is the first record of REE distribution in these organisms, and the results showed higher accumulations of these metals, U and Th in shells, probably related to the replacement of Ca during molting. Contents of Cd, Cr and Ni were similar in both tissues, but Cu, Zn and Pb were mostly accumulated in the claw muscle with concentrations above those considered safe for human consumption according to the Brazilian legislation. REE fractionation was different in the analyzed tissues being softer in the shells. The results provided evidences that the water absorbed during molting controls the chemistry of REE in shells. In contrast, the chemistry of REE in the claw muscle, in which was observed preferential absorption of light REE, is controlled by diet. REE fractionation obtained for the claw muscles was closely correlated to the observed in the contaminated substrate and in materials related to the production of phosphate fertilizers (contamination source), which supports their transference to this Ucides cordatus tissue without fractionation by the ingestion of sediments. Our results showed the potential use of crab tissues for monitoring REE and trace element sources in mangrove areas, with claw muscle exhibiting the contaminant source fingerprint.     

The value and limitations of using predetermined criteria in decision making for maternal-fetal interventions

Maternal-fetal interventions—such as prenatal fetal myelomeningocele (MMC) repair—are at the forefront of clinical innovation within maternal-fetal medicine, pediatric surgery, and neonatology. Many centers determine eligibility for innovative procedures using pre-determined inclusion and exclusion criteria based on seminal studies, for example, the “Management of Myelomeningocele Study” for prenatal MMC repair. What if a person's clinical presentation does not conform to predetermined criteria for maternal-fetal intervention? Does changing criteria on a case-by-case basis (i.e., ad hoc) constitute an innovation in practice and flexible personalized care or transgression of commonly held standards with potential negative consequences? We outline principle-based, bioethically justified answers to these questions using fetal MMC repair as an example. We pay special attention to the historical origins of inclusion and exclusion criteria, risks and benefits to the pregnant person and the fetus, and team dynamics. We include recommendations for maternal-fetal centers facing these questions.     

Potential for natural and enhanced attenuation of sulphanilamide in a contaminated chalk aquifer

Understanding antibiotic biodegradation is important to the appreciation of their fate and removal from the environment. In this research an Isotope Ratio Mass Spectrometry(IRMS)method was developed to evaluate the extent of biodegradation of the antibiotic,sulphanilamide, in contaminated groundwater. Results indicted an enrichment in δ~(13)C of8.44‰ from-26.56(at the contaminant source) to-18.12‰(300 m downfield of the source).These results confirm reductions in sulphanilamide concentrations(from 650 to 10 mg/L)across the contaminant plume to be attributable to biodegradation(56%) vs. other natural attenuation processes, such as dilution or dispersion(42%). To understand the controls on sulphanilamide degradation ex-situ microcosms assessed the influence of sulphanilamide concentration, redox conditions and an alternative carbon source. Results indicated, high levels of anaerobic capacity(~50% mineralisation) to degrade sulphanilamide under high(263 mg/L), moderate(10 mg/L) and low(0.02 mg/L) substrate concentrations. The addition of electron acceptors; nitrate and sulphate, did not significantly enhance the capacity of the groundwater to anaerobically biodegrade sulphanilamide. Interestingly, where alternative carbon sources were present, the addition of nitrate and sulphate inhibited sulphanilamide biodegradation. These results suggest, under in-situ conditions, when a preferential carbon source was available for biodegradation, sulphanilamide could be acting as a nitrogen and/or sulphur source. These findings are important as they highlight sulphanilamide being used as a carbon and a putative nitrogen and sulphur source, under prevailing iron reducing conditions.     

Detection of Potential Infectious Enteric Viruses in Fresh Produce by (RT)-qPCR Preceded by Nuclease Treatment

Foodborne illnesses associated with contaminated fresh produce are a common public health problem and there is an upward trend of outbreaks caused by enteric viruses, especially human noroviruses (HNoVs) and hepatitis A virus (HAV). This study aimed to assess the use of DNase and RNase coupled to qPCR and RT-qPCR, respectively, to detect intact particles of human adenoviruses (HAdVs), HNoV GI and GII and HAV in fresh produce. Different concentrations of DNase and RNase were tested to optimize the degradation of free DNA and RNA from inactivated HAdV and murine norovirus (MNV), respectively. Results indicated that 10 µg/ml of RNase was able to degrade more than 4 log₁₀ (99.99%) of free RNA, and 1 U of DNase degraded the range of 0.84–2.5 log₁₀ of free DNA depending on the fresh produce analysed. The treatment with nucleases coupled to (RT)-qPCR was applied to detect potential infectious virus in organic lettuce, green onions and strawberries collected in different seasons. As a result, no intact particles of HNoV GI and GII were detected in the 36 samples analysed, HAdV was found in one sample and HAV was present in 33.3% of the samples, without any reasonable distribution pattern among seasons. In conclusion, RT-qPCR preceded by RNase treatment of eluted samples from fresh produce is a good alternative to detect undamaged RNA viruses and therefore, potential infectious viruses. Moreover, this study provides data about the prevalence of enteric viruses in organic fresh produce from Brazil.     

Bibliometric analysis of studies involving e-waste: a critical review

Environmental Science and Pollution Research - The correct destination of waste is an essential factor for sustainable development. Electronic waste, which is very toxic, is the type of waste with...     

Habitat differences affect the nuclear morphology of the erythrocytes and the hepatic melanin in Leptodactylus fuscus (Anura) in the Brazilian Cerrado savanna

Environmental Science and Pollution Research - The sensitivity of anuran to the effects of habitat destruction and contamination has led to a preoccupying global decline in their populations....     

Study of controlled migration of cadmium and lead into foods from plastic utensils for children

Lead (Pb) is a highly neurotoxic chemical element known for reducing intelligence quotient (IQ) and promoting antisocial behavior in children and adolescents, while cadmium (Cd) is a carcinogenic bioaccumulative element. Both these metals are included in the priority pollutant list of the United States Environmental Protection Agency and in the WHO List of Chemicals of Major Public Health Concern, where contaminated foods and beverages are the most common pathways of exposure. The objective of this study was to determine total Cd and Pb levels in colored plastic utensils (cups, mugs, bowls, feeding bottles, and plates) for use by children and to measure the specific migration of these elements into beverages and foods. Total contaminant levels were determined using a handheld X-ray fluorescence analyzer. Specific migration tests were conducted using the simulant solutions acetic acid 3% (m/v) and water. Migration levels were determined by ICP-MS. Specific migration tests for Pb were also performed on commercially available samples (cola soft drink, orange juice, vinegar, and milk), with levels determined by graphite-furnace atomic absorption spectrometry (GF-AAS). A total of 674 utensils were analyzed in loco at major commercial centers in Greater São Paulo, of which 87 were purchased for containing Cd and Pb concentrations above permitted limits. Mean concentrations of the metals detected in the purchased utensils were 1110 ppm for Pb and 338 ppm for Cd. For specific migration assays, Pb levels were 187, 13, and 380 times above the permitted limit (0.01 mg.kg -1) for acetic acid, water, and orange juice, respectively. Cd levels were 50 and 2.4 times above the maximum permitted limit (0.005 mg.kg -1) for acetic acid and water, respectively. The districts where the utensils were purchased were grouped according to their social vulnerability index and compared using ANOVA. Pb levels were different between low and medium/high social vulnerability groups (p?=?0.006). The findings corroborate the initial hypothesis that these utensils constitute a major source of exposure to PTEs such as Cd and Pb, pointing to the need for stricter regulation and inspection by the Brazilian regulatory agencies.

     

Effects of La2O3 nanoparticles and bulk-La2O3 on the development of Pfaffia glomerata (Spreng.) Pedersen and respective nutrient element concentration

Environmental Science and Pollution Research - Nanoparticles (NPs) have been progressively applied in the last decades, which may impact the environment. Synthesis of pigments, growing, and...