Occurrence, spatial distribution and ecological risks of antibiotics in soil in urban agglomeration

Antibiotics in soil environment are regarded as emerging pollutants and have introduced increasing risks to soil ecosystem and human health in rapid urbanization areas. Identifying the occurrence and spatial variability of antibiotics in soils is an urgent issue in sustaining soil security. In this study, antibiotics in soils were investigated and analyzed in BeijingTianjin-Hebei urban agglomeration. The occurrence, spatial distribution, and related affecting factors of antibiotics in soils were identified and ecological risks of antibiotics in soil environment were assessed. Results showed that(1) The mean concentration of soil antibiotics in Beijing-Tianjin-Hebei urban agglomeration was 21.79 μg/kg. Land use substantially affected the occurrence and concentration of antibiotics in soils. Concentrations of antibiotics in cropland and orchard soils were 2-3 times higher than the other land use types.(2)The concentrations of antibiotics in soils in Beijing-Tianjin-Hebei urban agglomeration presented a spatial pattern of high values in southeast, and low values in northwest. Spatial variability of antibiotics in soils was closely related to the application of organic fertilizer and wastewater irrigation as well as topographical features. Furthermore, soil properties and land management policy had substantial influences on soil antibiotics, and soil heavy metals may aggravate the accumulation of antibiotics in soils.(3) Ecological risks assessment of antibiotics in soils demonstrated that erythromycin(ERY), sulfamethoxazole(SMX), and doxycycline(DOX) may introduce high risks to soil ecosystem health, and more attention should be paid to the areas with intensive human activities that had potential high risk to soil ecosystem health. This study suggests that scientific land and soil management should be considered to prevent soil antibiotic pollution and sustain soil security in urban agglomeration.

Neutralizing monoclonal antibodies present new prospects to treat SARS-CoV-2 infections

The coronavirus disease 2019(COVID-19)has caused global public health and economic crises.Thus,new therapeutic strategies and effective vaccines are urgently needed to cope with this severe pandemic.The development of a broadly neutralizing antibody against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is one of the attractive treatment strategies for COVID-19.Currently,the receptor-binding domain(RBD)of the spike(S)protein is the main target of neutralizing antibodies when SARS-CoV-2 enters human cells through an interaction between the S protein and the angiotensin-converting enzyme 2 expressed on various human cells.A single monoclonal antibody(mAb)treatment is prone to selective pressure due to increased possibility of targeted epitope mutation,leading to viral escape.In addition,the antibody-dependent enhancement effect is a potential risk of enhancing the viral infection.These risks can be reduced using multiple mAbs that target nonoverlapping epitopes.Thus,a cocktail therapy combining two or more antibodies that recognize different regions of the viral surface may be the most effective therapeutic strategy.