Photoaged nanoplastics with multienzyme-like activities significantly shape the horizontal transfer of antibiotic resistance genes.

Nanoplastics (NPs), identified as emerging pollutants, pose a great risk to environment and global public health, exerting profound influences on the prevalence and dissemination of antibiotic resistance genes (ARGs). Despite evidence suggesting that nano-sized plastic particles can facilitate the horizontal gene transfer (HGT) of ARGs, it is imperative to explore strategies for inhibiting the transfer of ARGs. Currently, limited information exists regarding the characteristics of environmentally aged NPs and their impact on ARGs propagation. Herein, we investigated the impact of photo-aged NPs on the transfer of ARG-carrying plasmids into Escherichia coli (E. coli) cells. Following simulated sunlight irradiation, photo-aged nano-sized polystyrene plastics (PS NPs) exhibited multiple enzyme-like activities, including peroxidase (POD) and oxidase (OXD), leading to a burst of reactive oxygen species (ROS). At relatively low concentrations (0.1, 1 µg/mL), both pristine and aged PS NPs facilitated the transfer of pUC19 and pHSG396 plasmids within E. coli due to moderate ROS production and enhanced cell membrane permeability. Intriguingly, at relatively high concentrations (5, 10 µg/mL), aged PS NPs significantly suppressed plasmids transformation. The non-unidirectional impact of aged PS NPs involved the overproduction of ROS (•OH and •O2-) via nanozyme activity, directly degrading ARGs and damaging plasmid structure. Additionally, oxidative damage to bacteria resulted from the presence of much toxic free radicals, causing physical damage to cell membranes, reduction of the SOS response and restriction of adenosine-triphosphate (ATP) supply, ultimately leading to inactivation of recipient cells. This study unveils the intrinsic multienzyme-like activity of environmentally aged NPs, highlighting their potential to impede the transfer and dissemination of ARGs.

Exploring the effect and mechanism of Hibiscus sabdariffa on urinary tract infection and experimental renal inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Hibiscus sabdariffa Linn., also known as roselle, is used in folk medicine as an anti-inflammatory agent. Urinary tract infection (UTI) is a common problem in long-term care facilities. However, effects of roselle on UTI and renal inflammation remained to be analyzed. AIM: Here we surveyed the effect of roselle drink on the prevention of UTI in long-term care facilities and analyzed the anti-inflammatory potential of roselle on lipopolysaccharide (LPS)-induced renal inflammation in mice. MATERIALS AND METHODS: Survey questionnaires and clinical observation were applied to evaluate the use of roselle and the incidence of UTI in long-term care facilities. Mice were administrated roselle orally for 7 consecutive days and then challenged with LPS. Anti-renal inflammatory effects of roselle were analyzed by microarray and immunohistochemical staining. RESULTS: Clinical observation showed that taking roselle drink in residents with urinary catheters reduced the incidence of UTI in long-term care facilities. Renal inflammation is a key event of UTI. Roselle suppressed LPS-induced nuclear factor-κB (NF-κB) activation in cells and LPS-induced interleukin-1ß production in mice a dose-dependent manner. Immunohistochemical staining showed that roselle inhibited LPS-induced NF-κB activation and inflammatory cell infiltration in kidney. Gene expression profiling further showed that roselle suppressed the expression of pro-inflammatory cytokine genes and enzyme genes involved in the production of prostaglandin and nitric oxide. In addition, NF-κB was the main transcription factor involved in the regulation of roselle-regulated gene expression in kidney. CONCLUSIONS: This is the first report applying clinical observation-guided transcriptomic study to explore the application and mechanism of roselle on UTI. Our findings suggested that roselle drink ameliorated LPS-induced renal inflammation via downregulation of cytokine network, pro-inflammatory product production, and NF-κB pathway. Moreover, this report suggested the potential benefit of roselle drink on UTI.