Whole genome sequence of Proteus mirabilis ChSC1905 strain harbouring a new SXT/R391-family ICE

Objectives: The aim of this study was to characterise the whole genome sequence of a multidrug-resistant (MDR) Proteus mirabilis strain ChSC1905 isolated from a swine farm in China. Methods: The genome was sequenced by Illumina NovaSeq and Oxford Nanopore platforms, and it was assembled via Canu v.1.5. The acquired antimicrobial resistance genes (ARGs) were identified by ResFinder. A conjugation experiment was carried out to determine the mobilisation of integrative and conjugative element. Results: Strain ChSC1905 exhibited a MDR phenotype. The genome of strain ChSC1905 was 4 038 038 bp in length with a GC content of 39.1%, which contained 3645 coding sequences and 110 RNA genes. A total of 23 acquired ARGs were identified, among which 21 ARGs including the clinically important resistance genes bla(CTX-M-65), cfr, fosA3, and aac(6')-Ib-cr were located on a SXT/R391 integrative and conjugative element (ICE). BLAST analysis showed that this new SXT/R391-family ICE (ICEPmiChnChSC1905 of 143 689 bp) was involved in sequence inversion mediated by ISVsa3 and genetic rearrangement mediated by IS26, and it could be transferred to E. coli EC600. Conclusion: In this study, we report the genome sequence of MDR P. mirabilis strain ChSC1905 that harboured a novel SXT/R391-family ICE (ICEPmiChnChSC1905) involved in genetic rearrangement in China, which promotes the diversity of ICE and should receive more attention. (C) 2022 The Authors. Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy.

Automated summary

This study characterized the whole genome sequence of a multidrug-resistant Proteus mirabilis strain isolated from a swine farm in China, revealing a novel integrative and conjugative element. The findings highlight the importance of studying genetic rearrangement and diversity of ICE.