Table 1_Distribution, carbapenem resistance and DTR dynamics of ESKAPEEc pathogens from pediatric bloodstream infections in Sichuan Province, 2017-2025: epidemiological characteristics under COVID-19 pandemic and emerging linezolid MIC creep.docx

Detection rates increased during the pandemic period and declined thereafter. Carbapenem resistance rates in Escherichia coli and Klebsiella pneumoniae were significantly higher in the post-pandemic period compared with the pre-pandemic baseline. The overall DTR prevalence was 8.6%, with Acinetobacter baumannii exhibiting the highest DTR burden (87.3%) despite a declining temporal trend, whereas DTR in K. pneumoniae increased progressively over time.

Reliance on CR criteria alone failed to identify a substantial proportion of DTR-positive E. coli isolates. All Staphylococcus aureus isolates remained susceptible to vancomycin and linezolid in vitro, with stable vancomycin MIC distributions; however, a high-MIC subpopulation among linezolid-treated MRSA isolates increased significantly over time (r=0.767, P = 0.016). Distinct age-stratified differences were observed in both pathogen distribution and resistance profiles.</p>Conclusions<p>The COVID-19 pandemic exerted a bidirectional and sustained impact on the pediatric ESKAPEEc landscape and resistance ecology in Sichuan Province.

Post-pandemic escalation of carbapenem resistance persists. The persistently high DTR burden in A. baumannii and early MIC drift toward linezolid in MRSA represent two critical regional threats in pediatric infectious disease management. Regional surveillance systems should incorporate DTR metrics alongside CR monitoring and implement age-stratified, precision-based antimicrobial stewardship strategies.</p>