# Characterization of the Antibiotic and Copper Resistance of Emergent Species of Onion-Pathogenic Burkholderia Through Genome Sequence Analysis and High-Throughput Sequencing of Differentially Enriched Random Transposon Mutants

## TL;DR

This study explores how two onion-pathogenic Burkholderia species resist antibiotics and copper by analyzing their genomes and transposon mutants.

## Contribution

The study identifies specific genes linked to copper resistance in B. cenocepacia through transposon mutagenesis and genome analysis.

## Key findings

- Genes involved in DNA integration, recombination, and cation transport are important for copper resistance in B. cenocepacia.
- Genes related to oxidative stress response and ABC transporters also contribute to copper resistance.
- Genes involved in penicillin binding, TCA cycle, and FAD binding hinder adaptation to copper toxicity.

## Abstract

The prevalence of antimicrobial resistance (AMR) in bacterial pathogens resulting from the intensive usage of antibiotics and antibiotic compounds is acknowledged as a significant global concern that impacts both human and animal health. In this study, we sequenced and analyzed the genomes of two emergent onion-pathogenic species of Burkholderia, B. cenocepacia CCRMBC56 and B. orbicola CCRMBC23, focusing on genes that are potentially associated with their high level of antibiotic and copper resistance. We also identified genes contributing to the copper resistance of B. cenocepacia CCRMBC56 through high-throughput analysis of mutated genes in random transposon mutant populations that were differentially enriched in a copper-containing medium. The results indicated that genes involved in DNA integration, recombination, and cation transport are important for the survival of B. cenocepacia CCRMBC56 in copper-stressed conditions. Furthermore, the fitness effect analysis identified additional genes crucial for copper resistance, which are involved in functions associated with the oxidative stress response, the ABC transporter complex, and the cell outer membrane. In the same analysis, genes related to penicillin binding, the TCA cycle, and FAD binding were found to hinder bacterial adaptation to copper toxicity. This study provides potential targets for reducing the copper resistance of B. cenocepacia and other copper-resistant bacterial pathogens.