Frontiers in Microbiology (Jul 2020)

Characterization of pTS14, an IncF2:A1:B1 Plasmid Carrying tet(M) in a Salmonella enterica Isolate

  • Ying-ying Liu,
  • Xiao-kang Liu,
  • Xiao-die Cui,
  • Min Chen,
  • Shuai-hua Li,
  • Dan-dan He,
  • Jian-hua Liu,
  • Li Yuan,
  • Gong-zheng Hu,
  • Yu-shan Pan

DOI
https://doi.org/10.3389/fmicb.2020.01523
Journal volume & issue
Vol. 11

Abstract

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The objective of this study was to explore the genetic and biological features of the tet(M)-harboring plasmid pTS14 in Salmonella enterica strain S14 isolated from a chicken fecal sample. Plasmid pTS14 was identified by conjugation, S1-pulsed-field gel electrophoresis (PFGE), Southern hybridization, and plasmid sequencing. The biological characteristics of pTS14 were assessed via stability, growth kinetics, and starvation survival experiments. Strain S14, belonging to ST3007, harbored a 119-kb tet(M)-bearing IncF2:A1:B1 conjugative plasmid pTS14. The plasmid pTS14 contained a novel transposon Tn6709 with the genetic structure IS26-tnpA1-tnpA2-Δorf13-LP-tet(M)-tnpX-ΔtnpR-IS26, and the resistance genes tet(B), tet(D), strAB, sul2, and blaTEM–1b. In addition, pTS14 was found to be highly stable in the recipient strain E. coli J53. The transconjugant TS14 exhibited a higher survival ratio than E. coli J53 under permanent starvation-induced stress. The tet(M)-bearing IncF2 epidemic plasmid lineage may accelerate the dissemination of tet(M) and other genes by coselection, which could constitute a potentially serious threat to clinical treatment regimens.

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