Research progress on source, risk assessment, and management of emerging pollutants in drinking water.

With the extensive production and use of various chemicals, emerging pollutants including environmental endocrine disrupting chemicals, perfluoro chemicals, antibiotics, and microplastics have been continuously entering the environment, and spread to water through multiple pathways. The pollution of these emerging pollutants raised continuous concerns for the safety of drinking water, threating the ecological environment and human health. In combination with international research progress, we discussed in detail about pollution, source, and risk assessment of emerging pollutants in drinking water. We further suggested and prospected the challenge of environmental management of emerging pollutants. This review could promote the public's understanding of emerging pollutants, and provide theoretical support for risk prevention and treatment of emerging pollutants in drinking water.

The prevalence of ampicillin-resistant opportunistic pathogenic bacteria undergoing selective stress of heavy metal pollutants in the Xiangjiang River, China.

The emergence of clinically relevant ß-lactam-resistant bacteria poses a serious threat to human health and presents a major challenge for medical treatment. How opportunistic pathogenic bacteria acquire antibiotic resistance and the prevalence of antibiotic-resistant opportunistic pathogenic bacteria in the environment are still unclear. In this study, we further confirmed that the selective pressure of heavy metals contributes to the increase in ampicillin-resistant opportunistic pathogens in the Xiangjiang River. Four ampicillin-resistant opportunistic pathogenic bacteria (Pseudomonas monteilii, Aeromonas hydrophila, Acinetobacter baumannii, and Staphylococcus epidermidis) were isolated on Luria-Bertani (LB) agar plates and identified by 16S rRNA sequencing. The abundance of these opportunistic pathogenic bacteria significantly increased in the sites downstream of the Xiangjiang River that were heavily influenced by metal mining activities. A microcosm experiment showed that the abundance of ß-lactam resistance genes carried by opportunistic pathogenic bacteria in the heavy metal (Cu2+ and Zn2+) treatment group was 2-10 times higher than that in the control. Moreover, heavy metals (Cu2+ and Zn2+) significantly increased the horizontal transfer of plasmids in pathogenic bacteria. Of particular interest is that heavy metals facilitated the horizontal transfer of conjugative plasmids, which may lead to the prevalence of multidrug-resistant pathogenic bacteria in the Xiangjiang River.

Reduction of fibrosis in dibutyltin dichloride-induced chronic pancreatitis using rat umbilical mesenchymal stem cells from Wharton's jelly.

OBJECTIVES: The objective of this study was to investigate the effects of rat umbilical cord mesenchymal stem cells (UCMSCs) from Wharton's jelly on dibutyltin dichloride (DBTC)-induced chronic pancreatitis (CP) and subsequent pancreatic fibrosis in rats. METHODS: A rat model of CP induced by DBTC was used. Male Sprague-Dawley rats were randomly divided into 4 groups: the control, DBTC, DBTC + UCMSCs, and control + UCMSC groups. Umbilical cord mesenchymal stem cells were administered intravenously on day 5 after the administration of DBTC. On days 14 and 28, the rats were evaluated morphologically and biochemically. The expression levels of inflammatory cytokines and chemokines in the pancreatic tissues of different groups were evaluated using quantitative real-time polymerase chain reaction. The activation of pancreatic stellate cells was estimated by immunochemistry and Western blot analysis of α-smooth muscle actin. RESULTS: Umbilical cord mesenchymal stem cells were detected in inflamed pancreatic tissues. Umbilical cord mesenchymal stem cell treatment improved the histological scores and alleviated the fibrosis of pancreas samples, The expression of cytokines in the DBTC + UCMSC group was significantly lower than that in the DBTC group. Also, pancreatic stellate cell activation was inhibited by UCMSC treatment. CONCLUSIONS: Xenogeneic transplantation of UCMSCs is a novel approach for the treatment of CP and subsequent fibrosis. Umbilical cord mesenchymal stem cells may be a promising therapeutic intervention for human CP in the future.