A global perspective on microbial risk factors in effluents of wastewater treatment plants

Effective monitoring and management of microbial risk factors in wastewater treatment plants(WWTPs)effluents require a comprehensive investigation of these risks.A global survey on microbial risk factors in WWTP effluents could reveal important insights into their risk features.This study aims to explore the abundance and types of antibiotic resistance genes(ARGs),virulence factor genes(VFGs),the vector of ARG/VFG,and dominant pathogens in global WWTP effluents.We collected 113 metagenomes of WWTP effluents from the Sequence Read Archive of the National Center for Biotechnology Information and characterized the microbial risk factors.Our results showed that multidrug resistance was the dominant ARG type,while offensive virulence factors were the most abundant type of VFGs.The most dominant types of ARGs in the vector of plasmid and phage were both aminoglycoside resistance,which is concerning as aminoglycosides are often a last resort for treating multi-resistant infections.Acinetobacter baumannii was the most dominant pathogen,rather than Escherichia coli,and a weak negative correlation between Escherichia coli and two other dominant pathogens(Acinetobacter baumannii and Bacteroides uniformis)suggests that using Escherichia coli as a biological indicator for all pathogens in WWTP effluents may not be appropriate.The Getah virus was the most dominant virus found in global WWTP effluents.Our study presents a comprehensive global-scale investigation of microbial risk factors in WWTP effluents,providing valuable insights into the potential risks associated with WWTP effluents and contributing to the monitoring and control of these risks.

A Plasma Membrane Polarity Sensor Harnessing Conjoined Twisted Intramolecular Charge Transfer Modulation and Charge Number Control Strategy

Polarity is a critical microenvironmental factor of the plasma membrane,which can offer valuable insights into various biological processes.Herein,we proposed a novel strategy for the construction of fluorescent agents to measure plasma membrane polarity by conjoining twisted intramolecular charge transfer(TICT)modulation and charge number control.It is shown that compounds with a stronger TICT tendency are more sensitive to polarity shifts due to the number of dialkylated amino groups present(from 1 to 3),and the molecules with two or more charged centers remain in the plasma membrane.Therefore,we developed two fluorescent agents with high polarity sensitivity,excellent turn-on ratios,and superior ability,to target the plasma membrane.In the wash-free fluorescence imaging and fluorescence lifetime tests,our designed agent could detect plasma membrane polarity with high precision,allowing effective distinction between cancer cells and normal cells based on their differences in plasma membrane polarity.Moreover,both fluorescence and fluorescence lifetime changes of the plasma membrane in the ferroptosis model established by Sorafenib confirmed an increase in plasma membrane polarity during cell ferroptosis.

Antimony oxidation and adsorption by in-situ formed biogenic Mn oxide and Fe–Mn oxides

Antimony（Sb）, which can be toxic at relatively low concentrations, may co-exist with Mn（Ⅱ）and/or Fe（Ⅱ） in some groundwater and surface water bodies. Here we investigated the potential oxidation and adsorption pathways of Sb（Ⅲ and V） species in the presence of Mn（Ⅱ） and Mn-oxidizing bacteria, with or without Fe（Ⅱ）. Batch experiments were conducted to determine the oxidation and adsorption characteristics of Sb species in the presence of biogenic Mn oxides（BMOs）, which were formed in-situ via the oxidation of Mn（Ⅱ） by a Mn-oxidizing bacterium（Pseudomonas sp. QJX-1）. Results indicated that Sb（Ⅲ） ions could be oxidized to Sb（V） ions by BMO, but only Sb（V） originating from Sb（Ⅲ） oxidation was adsorbed effectively by BMO. Introduced Fe（Ⅱ） was chemically oxidized to Fe OOH, the precipitates of which mixed with BMO to form a new compound, biogenic Fe–Mn oxides（BFMO）. The BMO part of the BFMO mainly oxidized and the Fe OOH of the BFMO mainly adsorbed the Sb species. In aquatic solutions containing both As（Ⅲ） and Sb（Ⅲ）, the BFMO that formed in-situ preferentially oxidized Sb over As but adsorbed As more efficiently. Chemical analysis and reverse transcription real-time polymerase chain reaction revealed that the presence of Fe（Ⅱ）, As（Ⅲ） and Sb（Ⅲ） accelerated the oxidation of Mn（Ⅱ） but inhibited the activity of Mn-oxidizing bacteria. These results provide significant insights into the biogeochemical pathways of Sb, Mn（Ⅱ） in aquatic ecosystems, with or without Fe（Ⅱ）.

Epilithic biofilm as a reservoir for functional virulence factors in wastewater-dominant rivers after WWTP upgrade

Virulence factors(VFs)confer upon pathogens the ability to cause various types of damage or diseases.Wastewater treatment plants(WWTPs)are important point sources for the emission of pathogens and VFs into receiving rivers.Conventional WWTP upgrades are often implemented to improve the water quality of receiving ecosystems.However,knowledge on the pathogens,VFs,and health risks to receiving aquatic ecosystems after upgrade remains limited.In this study,we investigated detailed pathogenic information,including taxa,pathogenicity,and health risk,in two wastewater-dominant rivers after WWTP upgrade.Using 16S rRNA gene sequencing,we screened 14 potential pathogens in water and epilithic biofilm samples,though they were significantly more enriched in the biofilms.Combining 16S rRNA and metagenomic sequencing data,we identified Pseudomonas and Aeromonas as the dominant pathogenic taxa carrying functional VFs(e.g.,mobility and offensive)in the epilithic biofilm.Moreover,strong pathogen-specific VF-host co-occurrence events were observed in the epilithic biofilm samples,indicating the importance of biofilms as reservoirs and vehicles for VFs.Further,we demonstrated that mobility VF is crucial for biofilm formation and pathogens in biofilm carrying offensive VF may be highly invasive.Quantification and health risk assessment suggested that the skin contact risk of P.aeruginosa carrying VFs was higher than the acceptable probability of 10^(-4)in both water and epilithic biofilm samples,which may threaten ecological and human health.