Whole genome sequencing and molecular epidemiology of paediatric Staphylococcus aureus bacteraemia

J Glob Antimicrob Resist. 2022 Jun:29:197-206. doi: 10.1016/j.jgar.2022.03.012. Epub 2022 Mar 25.

Abstract

Objectives: The role Staphylococcus aureus antimicrobial resistance genes and toxins play in disease severity, management and outcome in childhood is an emerging field requiring further exploration.

Methods: A prospective multisite study of Australian and New Zealand children hospitalised with S. aureus bacteraemia (SAB) occurred over 24 months (2017-2018). Whole genome sequencing (WGS) data were paired with clinical information from the ISAIAH cohort.

Results: 353 SAB isolates were sequenced; 85% methicillin-susceptible S. aureus ([MSSA], 301/353) and 15% methicillin-resistant S. aureus ([MRSA], 52/353). There were 92 sequence types (STs), most commonly ST5 (18%) and ST30 (8%), grouped into 23 clonal complexes (CCs), most frequently CC5 (21%) and CC30 (12%). MSSA comprised the majority of healthcare-associated SAB (87%, 109/125), with principal clones CC15 (48%, 11/21) and CC8 (33%, 7/21). Panton-Valentine leukocidin (PVL)-positive SAB occurred in 22% (76/353); predominantly MSSA (59%, 45/76), community-onset (92%, 70/76) infections. For community-onset SAB, the only microbiological independent predictor of poor outcomes was PVL positivity (aOR 2.6 [CI 1.0-6.2]).

Conclusion: From this WGS paediatric SAB data, we demonstrate the previously under-recognized role MSSA has in harbouring genetic virulence and causing healthcare-associated infections. PVL positivity was the only molecular independent predictor of poor outcomes in children. These findings underscore the need for further research to define the potential implications PVL-producing strains may have on approaches to S. aureus clinical management.

Keywords: Bacteraemia; Molecular; Outcomes; Paediatrics; Staphylococcus aureus; Whole genome sequencing.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Australia / epidemiology
  • Bacteremia* / epidemiology
  • Bacteremia* / microbiology
  • Child
  • Humans
  • Methicillin-Resistant Staphylococcus aureus*
  • Molecular Epidemiology
  • Prospective Studies
  • Staphylococcal Infections* / epidemiology
  • Staphylococcal Infections* / microbiology
  • Staphylococcus aureus
  • Whole Genome Sequencing