Clinical Predictors of Escherichia coli Versus Staphylococcus aureus Bacteremia at the Emergency Department

<b>Background:</b> Bacteremia is a life-threatening condition encountered in the emergency department (ED). <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> are among the most common pathogens, but early differentiation is challenging. Identifying clinical predictors may help guide empirical treatment while awaiting culture results. <b>Methods:</b> This retrospective analytical study included adults aged 18 years or older who presented with bacteremia in the ED between 1 January 2016 and 31 December 2018 and had blood cultures positive for either <i>S. aureus</i> or <i>E. coli</i>. Clinical predictors of <i>E. coli</i> bacteremia were identified using multivariable logistic regression analysis. <b>Results:</b> Among 327 patients, 272 (83.2%) had <i>E. coli</i> bacteremia. Significant predictors of <i>E. coli</i> bacteremia included hypertension (adjusted OR 2.12; 95% CI: 1.03-4.39; <i>p</i> = 0.041), solid organ tumor (adjusted OR 3.72; 95% CI: 1.63-8.51; <i>p</i> = 0.002), and higher body temperature (adjusted OR 1.49 per °C; 95% CI: 1.15-1.93; <i>p</i> = 0.002). The model showed good fit (Hosmer-Lemeshow <i>p</i> = 0.326). <b>Conclusions:</b> Patients presenting with hypertension, solid organ tumor, or elevated body temperature at the ED are more likely to have <i>E. coli</i> bacteremia than <i>S. aureus</i>. These predictors may support early empirical antibiotic decision-making.