Journal of Global Antimicrobial Resistance (Jun 2022)

A nosocomial salmonellosis outbreak caused by blaOXA-48–carrying, extensively drug-resistant Salmonella enterica serovar Goldcoast in a hospital respiratory care ward in Taiwan

  • Chih-Ming Chen,
  • Hui-Ling Tang,
  • Se-Chin Ke,
  • Yi-Pei Lin,
  • Min-Chi Lu,
  • Yi-Chyi Lai,
  • Bo-Han Chen,
  • You-Wun Wang,
  • Ru-Hsiou Teng,
  • Chien-Shun Chiou

Journal volume & issue
Vol. 29
pp. 331 – 338

Abstract

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ABSTRACT: Objectives: A nosocomial salmonellosis outbreak caused by Salmonella enterica serovar Goldcoast occurred in a respiratory care ward (RCW) of a hospital in central Taiwan between December 24, 2020, and January 21, 2021. Ten isolates recovered from 10 RCW residents were resistant to extended-spectrum cephalosporins. The resistance mechanism needs to be investigated. Methods: Whole-genome sequencing and antimicrobial susceptibility testing were conducted to determine the genetic resistance determinants and the phenotypic resistance in the isolates. Results: Each of the 10 outbreak isolates harbored an IncHI2 plasmid that carried 15 antimicrobial resistance genes aac(3)-IId, aadA22, aph(3’)-Ia, aph(6)-Id, arr-2, blaCTX-M-55, blaLAP-2, blaTEM-1, dfrA14, floR, lnu(F), qnrS13, sul2, sul3, tet(A), an efflux pump regulatory gene ramAp and an IncL plasmid carried a blaOXA-48. The outbreak strains were expected to be resistant to numerous antimicrobials, including aminoglycosides, b-lactams /inhibitors, tetracycline, rifamycin, lincosamide, sulfonamides, trimethoprim, phenicols, fluoroquinolones, and carbapenems. Two outbreak isolates displayed higher minimum inhibitory concentrations than the other eight isolates to cefmetazole and carbapenems, which was linked to a deficiency of a major facilitator superfamily transporter in the two isolates. Conclusion: The carbapenem-resistant outbreak strains could have been derived from extensively drug-resistant S. enterica Goldcoast strains, which have been a major pathogen in Taiwan since 2018, through the acquisition of a blaOXA-48-carrying plasmid. Special efforts are needed in Taiwan to monitor the spread of extremely resistant strains.

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