Risk for primary cephalosporin resistance in Gram-negative bacteremia

Objective: This study aimed to examine the clinical risk factors for cephalosporin resistance in patients with Gram-negative bacteremia caused by Escherichia coli (EC), Klebsiella pneumoniae (KP), Enterobacter cloacae (ENC), and Pseudomonas aeruginosa (PS). Methods: This retrospective cohort study included 400 adults with Gram-negative bacteremia. The goal was to review 100 cases involving each species and approximately half resistant and half susceptible to first-line cephalosporins, ceftriaxone (EC or KP), or cefepime (ENC or PS). Logistic regression was used to identify factors predictive of resistance. Results: A total of 378 cases of Gram-negative bacteremia were included in the analysis. Multivariate analysis identified significant risk factors for resistance, including admission from a chronic care hospital, skilled nursing facility, or having a history of infection within the prior 6 months (OR 3.00, P <.0001), requirement for mechanical ventilation (OR 3.76, P <.0001), presence of hemiplegia (OR 3.54, P =.0304), and presence of a connective tissue disease (OR 3.77, P =.0291). Conclusions: Patients without the identified risk factors should be strongly considered for receiving ceftriaxone or cefepime rather than carbapenems and newer broad-spectrum agents.