Eliminated colistin-resistance dissemination by a carbon nanotube-mediated CRISPR/Cas9 system – a combined effect of curing plasmid and conjugation blocking

Abstract

The spread of antibiotic resistance genes (ARGs) has become a major public health problem. The recent global spread of colistin-resistance gene mcr-1 via conjugative plasmids threatens the utility of colistin as the ‘last-resort’ antibiotic against Gram-negative pathogens. Despite the fact that multiple CRISPR/Cas9 systems targeting mcr-1 have been proposed, their poor delivery efficiency constrains effective eradication of the colistin-resistance trait. Herein, we demonstrated an efficient CRISPR/Cas delivery into wild colistin-resistant Escherichia coli (E. coli) using modified single-wall carbon nanotubes (SWCNTs). Our results revealed that the SWCNT–CRISPR complex could not only cure colistin-resistance but also inhibit the conjugation of mcr-1 plasmids. The dual function is mainly attributed to i) targeted mcr-1 cleaving activity by importing CRISPR/Cas9 systems; ii) the shortage of ATP supply for conjugation due to a disordered electron transfer chain by conductive SWCNTs. Our work demonstrates the feasibility of utilizing SWCNTs to facilitate CRISPR-based resistance eradication, opening up new possibilities for combating environmental antibiotic resistance with nanotechnology.