β-lactam resistant phenotypes reported by VITEK®2 advanced expert systemTM (AES) compared to whole genome sequencing in Enterobacterales from North and Latin America

Diagn Microbiol Infect Dis. 2024 Sep;110(1):116358. doi: 10.1016/j.diagmicrobio.2024.116358. Epub 2024 May 17.

Abstract

The VITEK®2 AES β-lactam phenotypes of 488 Enterobacterales from North and Latin America generated by the VITEK®2 were compared to the resistance genotypes provided by whole genome sequencing (WGS). The AES provided phenotypic reports for 447 (91.6 %) isolates, including isolates harbouring carbapenemases (195; 43.6 %), ESBLs (103; 23.0 %) and transferable AmpCs (tAmpC; 28; 6.3 %) genes, as well as wildtype isolates (WT; 121; 27.1 %). Overall, the AES report was accurate for 433/447 (96.9 %) isolates. The AES accurately reported carbapenemase, ESBL, and tAmpC phenotypes for 93.7 %, 93.7 %, and 98.4 % of isolates, respectively, and sensitivity/specificity rates were 96.4 %/91.7 %, 98.1 %/92.4 %, 82.1 %/99.5 %, and 100 %/98.8 %. 14 isolates carrying carbapenemase (7 total; 3 KPC, 2 MBL, 2 OXA-48-like), ESBL (2), and tAmpC-encoding genes (5) were not correctly identified by AES. The AES phenotypic report detected resistance mechanisms among Enterobacterales rapidly and could significantly aid future antimicrobial stewardship initiatives and patient care.

Keywords: AmpC; Antimicrobial susceptibility testing; Carbapenemase; ESBL; Whole genome sequencing; β-lactam resistance; β-lactamase.

Publication types

  • Comparative Study

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins* / genetics
  • Enterobacteriaceae Infections* / microbiology
  • Enterobacteriaceae* / drug effects
  • Enterobacteriaceae* / genetics
  • Genome, Bacterial / genetics
  • Genotype
  • Humans
  • Latin America
  • Microbial Sensitivity Tests*
  • North America
  • Phenotype*
  • Whole Genome Sequencing*
  • beta-Lactam Resistance / genetics
  • beta-Lactamases* / genetics
  • beta-Lactams / pharmacology

Substances

  • beta-Lactamases
  • Bacterial Proteins
  • Anti-Bacterial Agents
  • carbapenemase
  • beta-Lactams