Reversal of carbapenem-resistance in Shewanella algae by CRISPR/Cas9 genome editing.

• Emergence of carbapenem-resistant S. algae is a severe problem. • Re-sensitization of S. algae to carbapenem by CRISPR/Cas9 genome editing. • The bla OXA-55 -like gene is essential for carbapenem resistance in S. algae. • One-plasmid genome editing system for CRISPR/Cas9 genome editing in S. algae. • CRISPR/Cas9 genome editing is a promising approach to validate the gene function. Antibiotic resistance in pathogens is a growing threat to human health. Of particular concern is resistance to carbapenem, which is an antimicrobial agent listed as critically important by the World Health Organization. With the global spread of carbapenem-resistant organisms, there is an urgent need for new treatment options. Shewanella algae is an emerging pathogen found in marine environments throughout the world that has increasing resistance to carbapenem. The organism is also a possible antibiotic resistance reservoir in humans and in its natural habitat. The development of CRISPR/Cas9-based methods has enabled precise genetic manipulation. A number of attempts have been made to knock out resistance genes in various organisms. The study used a single plasmid containing CRISPR/Cas9 and recE/recT recombinase to reverse an antibiotic-resistant phenotype in S. algae and showed bla OXA-55 -like gene is essential for the carbapenem resistance. This result demonstrates a potential validation strategy for functional genome annotation in S. algae. [ABSTRACT FROM AUTHOR]