Enhanced uptake of antibiotic resistance genes in the presence of nanoalumina

Abstract

Nanomaterial pollution and the spread of antibiotic resistance genes (ARGs) are global public health and environmental concerns. Whether nanomaterials could aid the transfer of ARGs released from dead bacteria into live bacteria to cause spread of ARGs is still unknown. Here, we demonstrated that nano-Al2O3 could significantly promote plasmid-mediated ARGs transformation into Gram-negative Escherichia coli strains and into Gram-positive Staphylococcus aureus; however, bulk Al2O3 did not have this effect. Under suitable conditions, 7.4 × 10(6) transformants of E. coli and 2.9 × 10(5) transformants of S. aureus were obtained from 100 ng of a pBR322-based plasmid when bacteria were treated with nano-Al2O3. Nanoparticles concentrations, plasmid concentrations, bacterial concentrations, interaction time between the nanomaterial and bacterial cells and the vortexing time affected the transformation efficiency. We also explored the mechanisms underlying this phenomenon. Using fluorescence in situ hybridization and scanning electron microscopy, we found that nano-Al2O3 damaged the cell membrane to produce pores, through which plasmid could enter bacterial cells. Results from reactive oxygen species (ROS) assays, genome-wide expression microarray profiling and quantitative real-time polymerase chain reactions suggested that intracellular ROS damaged the cell membrane, and that an SOS response promoted plasmid transformation. Our results indicated the environmental and health risk resulting from nanomaterials helping sensitive bacteria to obtain antibiotic resistance.

Antimicrobal Resistance: Fecal Sanitation Strategies for Combatting a Global Public Health Threat

“…For example, advanced oxidation processes generate reactive oxygen species (ROS), which can damage cell membranes and elicit cellular SOS responses. The SOS response has been shown to increase integrase activity and the rate of gene recombination, increase the rate of HGT (Beaber et al, 2004;Guerin et al, 2009;Baharoglu et al, 2012), and increase competence which in turn may promote plasmid transformation in wastewater treatment (Ding et al, 2016). Other environmental stresses (Aertsen and Michiels, 2006), such as heat shock (Layton and Foster, 2005), starvation (Bernier et al, 2013), high hydrostatic pressure (Aertsen et al, 2004), and high pH, as well as the presence of antimicrobials, disinfection chemicals or UV have also been shown to induce the SOS response (Poole, 2012).…”

Nano-metal oxides induce antimicrobial resistance via radical-mediated mutagenesis

“…Accumulating evidence indicates the toxicological impacts of NMOs on microorganisms, algae, plants, human cells, and animals (Seabra and Duran, 2015; Chen et al, 2014). However, the impact of NMOs is still not fully understood, with one of the biggest knowledge gaps being their effects on antimicrobial resistance, which is an increasing threat to public health worldwide (Ding et al, 2016; Aruguete et al, 2013; WHO, 2014; Larsson et al, 2018).…”

“…Therefore, the development and spread of antimicrobial resistance that caused by nanoparticles should be regarded as an important aspect of nanotoxicology. However, there are only a few recent studies in this area (Ding et al, 2016; Qiu et al, 2012). Qiu et al first reported that nanoalumina could stimulate the conjugation (Qiu et al, 2012) and transformation (Ding et al, 2016) of plasmids encoding antibiotic resistance, which may accelerate the spread of antibiotic resistance in the environment.…”

A novel approach for increasing transformation efficiency in E. coli DH5α cells using silver nanoparticles

“…In the present study also transformation efficiency of the cells treated with calcium chloride alone was found to be lowest among the different treatments tried. According to Ding et al (2016), higher transformation efficiency was recorded while using nano alumina for transformation of non-competent E. coli (7.4 × 10 6 ) and Staphylococcus aureus (2.9 × 10 5 ) cells with pBR322. In the present study, tenfold increase in the transformation efficiency was recorded by treating the bacterial cells with 1 mg L −1 of silver nanoparticles for 60 min for competency induction compared to the conventional calcium chloride method.…”