Comparative clinical characteristics of non-typhoidal Salmonella and Escherichia coli bloodstream infections in children from Ningbo, China

Background Non-typhoidal Salmonella (NTS) and Escherichia coli ( E. coli ) are two main enterobacteria causing bloodstream infections (BSIs) in children. Understanding the clinical characteristics of NTS-BSIs and E. coli -BSIs is helpful for early empirical treatments. Methods A retrospective study was conducted using the medical records of pediatric patients hospitalized with NTS-BSI ( n = 47) and E. coli -BSI ( n = 99) at the Women and Children’s Hospital of Ningbo University from 2012 to 2023. Clinical characteristics, laboratory data, treatment, and outcome of NTS-BSI and E. coli -BSI were compared. Antimicrobial susceptibilities were also analyzed. Results During the study period, the detection rates of NTS-BSI and E. coli -BSI in blood cultures were 0.020% and 0.043%, respectively, both showing an overall upward trend, with the detection rate of E. coli -BSI being significantly higher than that of NTS-BSI. Compared with E. coli -BSI patients, NTS-BSI patients were older (median: 15 vs. 0.6 months, P = 0.008) and had higher rates of fever (93.6% vs. 59.6%, P < 0.001) and diarrhea (66.0% vs. 4.0%, P < 0.001) but lower rates of hospital stays over 2 weeks (14.9% vs. 53.5%, P < 0.001) and intensive care unit (ICU) admission (4.3% vs. 53.5%, P < 0.001). C-reactive protein (CRP) level was also lower in NTS-BSI patients compared with E. coli -BSI patients (16.45 mg/L vs. 21.65 mg/L, P < 0.001). Compared with E. coli strains, NTS isolates exhibited lower antibiotic resistance to ampicillin-sulbactam ( P = 0.021), ampicillin ( P < 0.001), trimethoprim-sulfamethoxazole ( P < 0.001), ceftriaxone ( P < 0.001), ceftazidime ( P = 0.041), and aztreonam ( P < 0.001). Conclusions This study highlighted significant differences in clinical characteristics between pediatric NTS-BSI and E. coli -BSI, particularly in age distribution, fever, diarrhea, CRP levels, antibiotic resistance, and treatment outcomes.