COVID-19 Lockdown Pandemic Period Effects in Highly Impacted Aquatic Ecosystems.

Human activities severely affect aquatic ecosystems: the lockdown restrictions due to SARS-CoV-2 (COVID-19) have proved that reducing anthropogenic activities can positively influence the environment and mitigate atmospheric pollution. In addition, studies on aquatic ecosystems have highlighted the decrease in suspended matter and pollutant concentrations associated with reduced marine transport and industrial activities. We evaluated the effects of the reduction of anthropogenic activities in highly impacted water ecosystems. Three of the sampling sites were on the Tiber River's lower stretch close to the urban area of Rome (Italy), and the other two were transitional waters located in the southern Latium region coastal area. These sampling sites have been studied by our research group for at least 20 years. The present study involved analysis of chemical and physicochemical parameters, biological communities, and land use. Microbiological fecal indicators and Salmonella spp. were also analyzed. There were two sampling campaigns, the first one in May 2020 (ID II) at the end of lockdown measures, and the second one a year later, in June 2021 (ID III). The data were compared with our old data, collected from 2002 to 2015 (ID I), to evaluate the potential effects of the restrictive measures. Biotic communities were dominated by pollution-tolerant taxa, indicating eutrophication and organic pollution. Furthermore, the high concentrations of microbiological indicators was mainly due to sewage from the urban area. The results of the research indicated no significant changes from past years (ID I) to 2020 (ID II) and 2021 (ID III). In conclusion, the restrictions adopted in Italy during the pandemic period were not sufficient to mitigate the heavy pressure of urbanization and agriculture that have long affected the studied aquatic ecosystems. Environ Toxicol Chem 2023;42:966-977. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Interaction between bacterial enteric pathogens and aquatic macrophytes. Can Salmonella be internalized in the plants used in phytoremediation processes?

The environment is considered a reservoir of pathogens and a possible source of infection for animals and humans. The association between enteric pathogens and food plants has been demonstrated in several studies, while few studies have addressed possible interactions between human pathogens and aquatic plants. This study, performed by setting mesocosms, evaluates the interaction between an enteric pathogen (Salmonella enterica serovar Napoli, S. Napoli) and a macrophyte (Phragmites australis (Cav.) Trin. ex Steudel) and the possible ability of the bacterium to internalize into the plant. The results show that S. Napoli concentration decreased gradually in growth solution without plants (control) while it was able to persist adhering to submerged parts of plants in treated mesocosms. The adhesion of the bacterium remained stable for 20 days, then decreased gradually until the end of the experiment. In addition, S. Napoli was able to internalize and colonize stems and leaves. In conclusion, the study suggests that macrophytes can represent an alternative environmental reservoir of pathogens for humans and animals. The adhesion to roots and rhizomes and the internalization could contribute to the bacterial persistence in the aquatic ecosystems by playing an important role in ecology and transmission of pathogens.

Need for a sustainable use of medicinal products: environmental impacts of ivermectin.

It is worldwide recognized that the use of pharmaceuticals for human and veterinary purposes could lead to unsustainable effects on the environment. A strategy to reduce the impact of pharmaceuticals on the environment has been recently established at European level, where guidelines to evaluate the impacts of veterinary drugs used to treat animal diseases are in place. The aim of this article is to focus on the worldwide used antiparasitic drug ivermectin (IVM) and its potential impact on the environment. A specific section is related to the IVM resistance that the massive use of this drug could generate enhancing the risk scenarios also for human health. The application of stringent measures for the veterinary use of this substance, in line with the recommendations provided by International frameworks such as One Health and EcoHealth, is recommended.

Phytoremediation applications in natural condition and in mesocosm: The uptake of cadmium by Lemna minuta Kunth, a non-native species in Italian watercourses.

Metal pollution in water and soil is an environmental and public health issue. Cadmium (Cd) is included in the list of priority hazardous substances in the European Water Framework Directive. Phytoremediation system is a cost-effective, plant-based approach that takes advantage of the ability of plants to concentrate elements and compounds from the environment and to metabolize various molecules in their tissues. We studied the presence and the importance of an invasive species, such as Lemna minuta, in the environment and the effects of Cd pollution on this species. Growth, removal, and tolerance were evaluated for different Cd concentrations and different times of plant exposure. Overall, the results show that L. minuta has a good capacity of growth, metal bioconcentration, and tolerance up to 3 days of exposure at 0.5 and 1.5 mg L-1 of Cd. In particular, L. minuta was able to accumulate Cd up to 3771 mg kg-1 on dry mass basis. We can conclude that L. minuta possesses a great capability of Cd absorption and accumulation, thus supporting a potential use of this species in designing a metal bioremediation system in phytoremediation field.

First isolation of Salmonella enterica serovar Napoli from wild birds in Italy.

Salmonella enterica serovar Napoli (S. Napoli) is an emerging serovar in Italy. It accounts for 2-4% of all serovars isolated from human infections. The zoonotic origin of this serovar is still unknown and this makes difficult to apply any control intervention. We report here the isolation of S. Napoli from a river nightingale (Cettia cetti, Temminck 1820) which represents the first description of this serovar from wild birds. This finding adds knowledge to the ecology of S. Napoli and addresses further studies aimed to assess the epidemiologic link between S. Napoli isolated from wild birds, food, environmental sources and human infections.