Le VVHLeón-Quezada RIBiggs PJRakonjac J2024-01-082024-07-252022-08-122024-01-082024-07-252022-08-12Le VVH, León-Quezada RI, Biggs PJ, Rakonjac J. (2022). A large chromosomal inversion affects antimicrobial sensitivity of Escherichia coli to sodium deoxycholate.. Microbiology (Reading). 168. 8.1350-0872https://mro.massey.ac.nz/handle/10179/70691Resistance to antimicrobials is normally caused by mutations in the drug targets or genes involved in antimicrobial activation or expulsion. Here we show that an Escherichia coli strain, named DOC14, selected for increased resistance to the bile salt sodium deoxycholate, has no mutations in any ORF, but instead has a 2.1 Mb chromosomal inversion. The breakpoints of the inversion are two inverted copies of an IS5 element. Besides lowering deoxycholate susceptibility, the IS5-mediated chromosomal inversion in the DOC14 mutant was found to increase bacterial survival upon exposure to ampicillin and vancomycin, and sensitize the cell to ciprofloxacin and meropenem, but does not affect bacterial growth or cell morphology in a rich medium in the absence of antibacterial molecules. Overall, our findings support the notion that a large chromosomal inversion can benefit bacterial cells under certain conditions, contributing to genetic variability available for selection during evolution. The DOC14 mutant paired with its isogenic parental strain form a useful model as bacterial ancestors in evolution experiments to study how a large chromosomal inversion influences the evolutionary trajectory in response to various environmental stressors.(c) 2021 The Author/sCC BY 4.0https://creativecommons.org/licenses/by/4.0/IS5 elementantimicrobial susceptibilitychromosomal inversionhybrid genome assemblysodium deoxycholateAnti-Bacterial AgentsChromosome InversionDeoxycholic AcidDrug Resistance, BacterialEscherichia coliEscherichia coli InfectionsHumansMicrobial Sensitivity TestsJournal article10.1099/mic.0.0012321465-2080journal-articlehttps://www.ncbi.nlm.nih.gov/pubmed/35960647001232