The rapid spread of SARS-COV-2 Omicron variant in Italy reflected early through wastewater surveillance

The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide, raising serious concerns. A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between 11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing. Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7 December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive wastewater samples rising from 1.0% (1/104 samples) in the week 5–11 December, to 17.5% (25/143 samples) in the week 12–18, to 65.9% (89/135 samples) in the week 19–25, in line with the increase in cases of infection with the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in which the variant was detected increased from one in the first week, to 11 in the second, and to 17 in the last one. The presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples, and by Sanger sequencing in 66% (64/97) of PCR amplicons. In conclusion, we designed an RT-qPCR assay capable to detect the Omicron variant, which can be successfully used for the purpose of wastewater-based epidemiology. We also described the history of the introduction and diffusion of the Omicron variant in the Italian population and territory, confirming the effectiveness of sewage monitoring as a powerful surveillance tool

Metal Oxide Thin Films Grafted on Silica Gel Surfaces: Recent Advances on the Analytical Application of these Materials

In the highly dispersed MxOy monolayer film on a porous SiO2 surface, denoted as SiO2/MxOy, the Si-O-M covalent bond formed on the SiO2 surface restricts the mobility of the attached oxide resulting in coordinatively unsaturated metal oxides (LAS) in addition to the Brønsted acid sites (BAS). The BAS arise from the MOH and SiOH groups, the latter due to the unreacted silanol groups. As the attached oxides are strongly immobilized on the surface, they are also thermally very stable. The amphoteric character of most of the attached oxides allows the immobilization of various chemical species, acid or bases, resulting in a wide application of these surface modified materials. In this work many of the recent applications of these MxOy coated silica surfaces are described, such as selective adsorbents, in preconcentration processes, as new packing material for use in HPLC, support for immobilization of enzymes, amperometric electrodes, sensors and biosensor

Root and shoot response to nickel in hyperaccumulator and non\u2010hyperaccumulator species

The soil\u2013root interface is the micro\u2010ecosystem where roots uptake metals. However, less than 10% of hyperaccumulators\u2019 rhizosphere has been examined. The present study evaluated the root and shoot response to nickel in hyperaccumulator and non\u2010hyperaccumulator species, through the analysis of root surface and biomass and the ecophysiological response of the related aboveground biomass. Ni\u2010hyperaccumulators Alyssoides utriculata (L.) Medik. and Noccaea caerulescens (J. Presl and C. Presl) F.K. Mey. and non\u2010hyperaccumulators Alyssum montanum L. and Thlaspi arvense L. were grown in pot on Ni\u2010spiked soil (0\u20131000 mg Ni kg 121, total). Development of root surfaces was analysed with ImageJ; fresh and dry root biomass was determined. Photosynthetic efficiency was performed by analysing the fluorescence of chlorophyll a to estimate the plants\u2019 physiological conditions at the end of the treatment. Hyperaccumulators did not show a Ni-dependent decrease in root surfaces and biomass (except Ni 1000 mg kg 121 for N. caerulescens). The non\u2010hyperaccumulator A. montanum suffers metal stress which threatens plant development, while the excluder T. arvense exhibits a positive ecophysiological response to Ni. The analysis of the root system, as a component of the rhizosphere, help to clarify the response to soil nickel and plant development under metal stress for bioremediation purposes

Metal-tolerant plant Response to soil contamination

The global climate is predicted to change drastically over the next century. From literature it is clear that certain climate change scenarios will have effects on metal phytoremediation and plant\u2013microorganism interactions, which are increasingly being explored. The hyperaccumulator plants actively take up large amounts of metals from the soil at concentrations 100\u20131000-fold higher than in other species, showing no symptoms of phytotoxicity, resulting in a strong metal-hypertolerance. However, there is a lack of knowledge about hyperaccumulators, particularly as regards rhizosphere processes. The aim of this study is to assess the metal-tolerant plant response to abiotic stress by nickel (Ni) through seed germination tests and through the evaluation of potential morpho-functional root alterations using hyperaccumulator and non-hyperaccumulator species under controlled growing conditions. Growing substrates were spiked with Ni at different concentrations. The Image J analysis of roots was used to evaluate parameters like root elongation, surface area and number of lateral roots. Furthermore, Ni-hyperaccumulator plants and soil samples were collected on metalliferous soils to characterize the rhizospheric microbiota. The presence of Ni seems to determine a general decrease of seed germination and a greater root development in hyperaccumulator species, compared to non-hyperaccumulator species. Moreover, the bacterial isolations show a greater number of bacterial colonies in the rhizosphere soils compared to bare soils. The development of an integrated system plant-rhizobiota, using the rhizobiota as a natural metal-chelator could improve metal uptake, alleviating the nickel stress and promoting the recolonization of metal-polluted areas