Phenotypic H-Antigen Typing by Mass Spectrometry Combined with Genetic Typing of H Antigens, O Antigens, and Toxins by Whole-Genome Sequencing Enhances Identification of Escherichia coli Isolates Academic Article uri icon

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abstract

  • Mass spectrometry-based phenotypic H-antigen typing (MS-H) combined with whole-genome-sequencing-based genetic identification of H antigens, O antigens, and toxins (WGS-HOT) was used to type 60 clinicalEscherichia coliisolates, 43 of which were previously identified as nonmotile, H type undetermined, or O rough by serotyping or having shown discordant MS-H and serotyping results. Whole-genome sequencing confirmed that MS-H was able to provide more accurate data regarding H antigen expression than serotyping. Further, enhanced and more confident O antigen identification resulted from gene cluster based typing in combination with conventional typing based on the gene pair comprisingwzxandwzyand that comprisingwzmandwzt. The O antigen was identified in 94.6% of the isolates when the two genetic O typing approaches (gene pair and gene cluster) were used in conjunction, in comparison to 78.6% when the gene pair database was used alone. In addition, 98.2% of the isolates showed the existence of genes for various toxins and/or virulence factors, among which verotoxins (Shiga toxin 1 and/or Shiga toxin 2) were 100% concordant with conventional PCR based testing results. With more applications of mass spectrometry and whole-genome sequencing in clinical microbiology laboratories, this combined phenotypic and genetic typing platform (MS-H plus WGS-HOT) should be ideal for pathogenicE. colityping.

authors

  • Cheng, Keding
  • Chui, Huixia
  • Domish, Larissa
  • Sloan, Angela
  • Hernandez, Drexler
  • McCorrister, Stuart
  • Robinson, Alyssia
  • Walker, Matthew
  • Peterson, Lorea AM
  • Majcher, Miles
  • Ratnam, Sam
  • Haldane, David JM
  • Bekal, Sadjia
  • Wylie, John
  • Chui, Linda
  • Tyler, Shaun
  • Xu, Bianli
  • Reimer, Aleisha
  • Nadon, Celine
  • Knox, J David
  • Wang, Gehua

publication date

  • August 2016