Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2023

Bacteraemia and Antimicrobial Resistance in Paediatric Patients across Australia, 2020-21 (93401)

Anita Williams 1 , Geoff Coombs 2 3 4 , Jan Bell 5 , Denise Daley 3 4 , Christopher Blyth 1 6 7 8
  1. Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, Nedlands, WA, Australia
  2. Antimicrobial Resistance and Infectious Disease (AMRID) Research Laboratory, Murdoch University, Murdoch, WA, Australia
  3. Department of Microbiology, PathWest Laboratory Medicine WA, Fiona Stanely Hospital, Murdoch, WA, Australia
  4. Australian Group on Antimicrobial Resistance, Fiona Stanely Hospital, Murdoch, WA, Australia
  5. Australian Group on Antimicrobial Resistance, Adelaide, SA, Australia
  6. Department of Infectious Diseases, Perth Children's Hospital, Nedlands, WA, Australia
  7. Department of Microbiology, PathWest Laboratory Medicine WA, QEII Medical Centre, Nedlands, WA, Australia
  8. School of Medicine, The University of Western Australia, Nedlands, WA, Australia

Bacteraemia is associated with significant morbidity and mortality in children. Increasing rates of antimicrobial resistance (AMR) are reported globally, with bacteraemia surveillance providing a unique opportunity to assess AMR and outcomes.

The Australian Group on Antimicrobial Resistance (AGAR) program captures clinical and microbiological data of Staphylococcus aureus, Enterococcus spp. and key Gram-negative isolates detected in blood cultures from across Australia. EUCAST 2022 was used for MIC interpretation through the AMR package in R (version 1.8.2).

Thirty laboratories across Australia submitted 25,958 isolates from 1 January 2020 to 31 December 2021, with 1,679 isolates (6.5%) from patients aged <18 years. The most reported isolates were S. aureus (36.2%) and Escherichia coli (22.5%). E. coli was the most frequent isolate in patients <1 year, whereas S. aureus was predominant in patients ≥1 year. Most patients were aged <1 year (46%); neonates (≤28 days) accounted for 18% of all isolates reported. At 30 days, 3.5% of patients had died, with 22.0% of patients who died had a multi-drug resistant organism.

Eight hundred Enterobacterales were reported over the two years; 47.3% were E. coli, 15.3% were Klebsiella pneumoniae complex and 13.3% were Enterobacter cloacae complex. The proportion of Enterobacterales resistant to gentamicin/tobramycin was 11.6%, to ceftazidime/ceftriaxone was 12.9%, and 13.2% to ciprofloxacin. Seventy-four isolates (9.4%) had either ESBL (60), pAmpC (8), ESBL and pAmpC (3), carbapenemase (2), or ESBL and carbapenemase (1) genes.  

There were 61 isolates of Pseudomonas aeruginosa with 19.7% resistant to piperacillin-tazobactam and 13.1% resistant to cefepime/ceftazidime and 9.8% to ciprofloxacin.

Of the 607 S. aureus reported in 2020-21, 13.2% were methicillin-resistant (MRSA), and the majority were community-onset. Overall, 13.2% of S. aureus isolates were resistant to erythromycin, 12.4% to clindamycin, and 5.3% to ciprofloxacin, with resistance higher in MRSA than methicillin-susceptible isolates. The most frequently isolated MRSA strain was ST93-IV.

Enterococcus spp. (n: 170) were more frequently hospital onset and from patients aged <1 year. Eight isolates were resistant to vancomycin (4.7%), and three to teicoplanin (1.8%); all were E. faecium and hospital onset.