Risk factors and microbiological features of recurrent Escherichia coli bloodstream infections

Understanding the risk factors and microbiological features in recurrent Escherichia coli BSI is helpful for clinicians. Data of patients with E. coil BSI from 2017 to 2018 were collected. Antimicrobial resistance rates of E. coli were determined. We also identified the ST131 and ESBL genotype to evaluate the molecular epidemiology of E. coli. Whole genome sequencing was conducted on the available ESBL-producing E. coli samples. Of 808 patients with E. coli BSI, 57 (6.31%) experienced recurrence; 29 developed at 4-30 days after initial BSI (early onset recurrence) and 28 at 31-270 days after initial BSI (late onset recurrence). One hundred forty-nine patients with single episode, whose samples were available for determining the molecular epidemiology, were selected for comparison. Vascular catheterization (adjusted odds ratio [aOR], 4.588; 95% confidence interval [CI], 1.049-20.068), ESBL phenotype (aOR, 2.037; 95% CI, 1.037-3.999) and SOFA score ≥9 (aOR, 3.210; 95% CI, 1.359-7.581) were independent risk factors for recurrence. The proportion of ST131 and ESBL genotype was highest in early onset recurrent BSI (41.4% and 41.4%, respectively), from which E. coil had the highest resistance rates to most antimicrobial agents. Whole genome sequencing on 27 of ESBL-producing E. coli (11 from single episode, 11 from early onset recurrence, and 5 from late onset recurrence) demonstrated that various virulence factors, resistant genes, and plasmid types existed in isolates from all types of BSI. Risk factors contributing to the recurrence and microbiological features of E. coli causing recurrent BSI may be helpful for management planning in the clinical setting.