CeO2 Nanoparticles-Regulated Plasmid Uptake and Bioavailability for Reducing Transformation of Extracellular Antibiotic Resistance Genes

Unveiling the role of uranium in enhancing the transformation of antibiotic resistance genes

Transformation represents one of the most important pathways for the horizontal transfer of antibiotic resistance genes (ARGs), which enables competent bacteria to acquire extracellular ARGs from the surrounding environment. Both heavy metals and irradiation have been demonstrated to influence the bacterial transformation process. However, the impact of ubiquitously occurring radioactive heavy metals on the transformation of ARGs remains largely unknown. Here, we showed that a representative radioactive nuclide, uranium (U), at environmental concentrations (0.005-5 mg/L), improved the transformation frequency of resistant plasmid pUC19 into Escherichia coli by 0.10-0.85-fold in a concentration-dependent manner. The enhanced ARGs transformation ability under U stress was demonstrated to be associated with reactive oxygen species (ROS) overproduction, membrane damage, and up-regulation of genes related to DNA uptake and recombination. Membrane permeability and ROS production were the predominant direct and indirect factors affecting transformation ability, respectively. Our findings provide valuable insight into the underlying mechanisms of the impacts of U on the ARGs transformation process and highlight concerns about the exacerbated spread of ARGs in radioactive heavy metal-contaminated ecosystems, especially in areas with nuclear activity or accidents.

Nano-CeO2 activates physical and chemical defenses of garlic (Allium sativum L.) for reducing antibiotic resistance genes in plant endosphere

The transmission of manure- and wastewater-borne antibiotic-resistant bacteria (ARB) to plants contributes to the proliferation of antimicrobial resistance in agriculture, necessitating effective strategies for preventing the spread of antibiotic resistance genes (ARGs) from ARB in the environment to humans. Nanomaterials are potential candidates for efficiently controlling the dissemination of ARGs. The present study investigated the abundance of ARGs in hydroponically grown garlic (Allium sativum L.) following nano-CeO2 (nCeO2) application. Specifically, root exposure to nCeO2 (1, 2.5, 5, 10 mg L-1, 18 days) reduced ARG abundance in the endosphere of bulbs and leaves. The accumulation of ARGs (cat, tet, and aph(3')-Ia) in garlic bulbs decreased by 24.2-32.5 % after nCeO2 exposure at 10 mg L-1. Notably, the lignification extent of garlic stem-disc was enhanced by 10 mg L-1 nCeO2, thereby accelerating the formation of an apoplastic barrier to impede the upward transfer of ARG-harboring bacteria to garlic bulbs. Besides, nCeO2 upregulated the gene expression related to alliin biosynthesis and increased allicin content by 15.9-16.2 %, promoting a potent antimicrobial defense for reducing ARG-harboring bacteria. The potential exposure risks associated with ARGs and Ce were evaluated according to the estimated daily intake (EDI). The EDI of ARGs exhibited a decrease exceeding 95 %, while the EDI of Ce remained below the estimated oral reference dose. Consequently, through stimulating physical and chemical defenses, nCeO2 contributed to a reduced EDI of ARGs and Ce, highlighting its potential for controlling ARGs in plant endosphere within the framework of nano-enabled agrotechnology.

Nanotechnology's frontier in combatting infectious and inflammatory diseases: prevention and treatment

Inflammation-associated diseases encompass a range of infectious diseases and non-infectious inflammatory diseases, which continuously pose one of the most serious threats to human health, attributed to factors such as the emergence of new pathogens, increasing drug resistance, changes in living environments and lifestyles, and the aging population. Despite rapid advancements in mechanistic research and drug development for these diseases, current treatments often have limited efficacy and notable side effects, necessitating the development of more effective and targeted anti-inflammatory therapies. In recent years, the rapid development of nanotechnology has provided crucial technological support for the prevention, treatment, and detection of inflammation-associated diseases. Various types of nanoparticles (NPs) play significant roles, serving as vaccine vehicles to enhance immunogenicity and as drug carriers to improve targeting and bioavailability. NPs can also directly combat pathogens and inflammation. In addition, nanotechnology has facilitated the development of biosensors for pathogen detection and imaging techniques for inflammatory diseases. This review categorizes and characterizes different types of NPs, summarizes their applications in the prevention, treatment, and detection of infectious and inflammatory diseases. It also discusses the challenges associated with clinical translation in this field and explores the latest developments and prospects. In conclusion, nanotechnology opens up new possibilities for the comprehensive management of infectious and inflammatory diseases.