Comparison of outcomes in urinary tract infections caused by AmpC-harboring organisms treated with AmpC stable versus AmpC susceptible agents

Abstract

There is minimal data on the optimal treatment of lower inoculum infections such as urinary tract infections (UTIs) caused by SPICE organisms which encode the betalactamase enzyme, AmpC. This single-center, retrospective review of adult hospitalized patients with UTIs caused by a SPICE organism compared outcomes amongst patients treated with drugs susceptible to AmpC hydrolysis versus drugs stable against AmpC. Of 156 patients, similar rates of clinical response, 30-day infection related readmission, 30-day infection recurrence, 30-day mortality rates, and median length of hospital stay were found between the two groups. Notably, 44% of patients with ceftriaxone resistance reported had recent β-lactam exposure versus only 11% of patients without ceftriaxone resistance (P=0.002). Based on our data, there does not appear to be a difference in clinical response or any of the secondary outcomes in patients with UTIs treated with AmpC stable and AmpC susceptible agents.