Frontiers in Microbiology (Jan 2022)

Nosocomial Outbreak of Carbapenemase-Producing Proteus mirabilis With Two Novel Salmonella Genomic Island 1 Variants Carrying Different blaNDM–1 Gene Copies in China

  • Lang Yang,
  • Hong He,
  • Qichao Chen,
  • Qichao Chen,
  • Kaiying Wang,
  • Kaiying Wang,
  • Yanfeng Lin,
  • Yanfeng Lin,
  • Peihan Li,
  • Peihan Li,
  • Jinhui Li,
  • Xiong Liu,
  • Leili Jia,
  • Hongbin Song,
  • Hongbin Song,
  • Peng Li

DOI
https://doi.org/10.3389/fmicb.2021.800938
Journal volume & issue
Vol. 12

Abstract

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NDM-1-producing multidrug-resistant Proteus mirabilis brings formidable clinical challenges. We report a nosocomial outbreak of carbapenem-resistant P. mirabilis in China. Six P. mirabilis strains collected in the same ward showed close phylogenetic relatedness, indicating clonal expansion. Illumina and MinION sequencing revealed that three isolates harbored a novel Salmonella genomic island 1 carrying a blaNDM–1 gene (SGI1-1NDM), while three other isolates showed elevated carbapenem resistance and carried a similar SGI1 but with two blaNDM–1 gene copies (SGI1-2NDM). Four new single nucleotide mutations were present in the genomes of the two-blaNDM–1-harboring isolates, indicating later emergence of the SGI1-2NDM structure. Passage experiments indicated that both SGI variants were stably persistent in this clone without blaNDM–1 copy number changes. This study characterizes two novel blaNDM–1-harboring SGI1 variants in P. mirabilis and provides a new insight into resistance gene copy number variation in bacteria.

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